Cat's Eye

All for One

2012-02-18T00:12:00.002-06:00

Thompson speaks for all of us when he indicates that he's ready for spring to arrive. Rather than sitting on a blanket on the couch he'd much rather be sitting in an open window enjoying the fresh air...

Diego-san's Haiku

2012-02-17T00:04:00.001-06:00

I eye you, so that
we see eye to eye even
though we're not equal

3D

2012-02-16T00:19:00.003-06:00

This is what it would look like if you had Theo laying on your chest. Betcha wish you had Theo laying on your chest.

This Explains A Lot About Me...

2012-02-15T00:35:00.001-06:00

How Your Cat Is Making You Crazy

Jaroslav Flegr is no kook. And yet, for years, he suspected his mind had been taken over by parasites that had invaded his brain. So the prolific biologist took his science-fiction hunch into the lab. What he’s now discovering will startle you. Could tiny organisms carried by house cats be creeping into our brains, causing everything from car wrecks to schizophrenia? A biologist’s science- fiction hunch is gaining credence and shaping the emerging science of mind- controlling parasites. By Kathleen McAuliffe The Atlantic

No one would accuse Jaroslav Flegr of being a conformist. A self-described “sloppy dresser,” the 63-year-old Czech scientist has the contemplative air of someone habitually lost in thought, and his still-youthful, square-jawed face is framed by frizzy red hair that encircles his head like a ring of fire.

Certainly Flegr’s thinking is jarringly unconventional. Starting in the early 1990s, he began to suspect that a single-celled parasite in the protozoan family was subtly manipulating his personality, causing him to behave in strange, often self-destructive ways. And if it was messing with his mind, he reasoned, it was probably doing the same to others.

The parasite, which is excreted by cats in their feces, is called Toxoplasma gondii (T. gondii or Toxo for short) and is the microbe that causes toxoplasmosis—the reason pregnant women are told to avoid cats’ litter boxes. Since the 1920s, doctors have recognized that a woman who becomes infected during pregnancy can transmit the disease to the fetus, in some cases resulting in severe brain damage or death. T. gondii is also a major threat to people with weakened immunity: in the early days of the AIDS epidemic, before good antiretroviral drugs were developed, it was to blame for the dementia that afflicted many patients at the disease’s end stage. Healthy children and adults, however, usually experience nothing worse than brief flu-like symptoms before quickly fighting off the protozoan, which thereafter lies dormant inside brain cells—or at least that’s the standard medical wisdom.

But if Flegr is right, the “latent” parasite may be quietly tweaking the connections between our neurons, changing our response to frightening situations, our trust in others, how outgoing we are, and even our preference for certain scents. And that’s not all. He also believes that the organism contributes to car crashes, suicides, and mental disorders such as schizophrenia. When you add up all the different ways it can harm us, says Flegr, “Toxoplasma might even kill as many people as malaria, or at least a million people a year.”

An evolutionary biologist at Charles University in Prague, Flegr has pursued this theory for decades in relative obscurity. Because he struggles with English and is not much of a conversationalist even in his native tongue, he rarely travels to scientific conferences. That “may be one of the reasons my theory is not better known,” he says. And, he believes, his views may invite deep-seated opposition. “There is strong psychological resistance to the possibility that human behavior can be influenced by some stupid parasite,” he says. “Nobody likes to feel like a puppet. Reviewers [of my scientific papers] may have been offended.” Another more obvious reason for resistance, of course, is that Flegr’s notions sound an awful lot like fringe science, right up there with UFO sightings and claims of dolphins telepathically communicating with humans.

But after years of being ignored or discounted, Flegr is starting to gain respectability. Psychedelic as his claims may sound, many researchers, including such big names in neuroscience as Stanford’s Robert Sapolsky, think he could well be onto something. Flegr’s “studies are well conducted, and I can see no reason to doubt them,” Sapolsky tells me. Indeed, recent findings from Sapolsky’s lab and British groups suggest that the parasite is capable of extraordinary shenanigans. T. gondii, reports Sapolsky, can turn a rat’s strong innate aversion to cats into an attraction, luring it into the jaws of its No. 1 predator. Even more amazing is how it does this: the organism rewires circuits in parts of the brain that deal with such primal emotions as fear, anxiety, and sexual arousal. “Overall,” says Sapolsky, “this is wild, bizarre neurobiology.” Another academic heavyweight who takes Flegr seriously is the schizophrenia expert E. Fuller Torrey, director of the Stanley Medical Research Institute, in Maryland. “I admire Jaroslav for doing [this research],” he says. “It’s obviously not politically correct, in the sense that not many labs are doing it. He’s done it mostly on his own, with very little support. I think it bears looking at. I find it completely credible.”

What’s more, many experts think T. gondii may be far from the only microscopic puppeteer capable of pulling our strings. “My guess is that there are scads more examples of this going on in mammals, with parasites we’ve never even heard of,” says Sapolsky.

Familiar to most of us, of course, is the rabies virus. On the verge of killing a dog, bat, or other warm-blooded host, it stirs the animal into a rage while simultaneously migrating from the nervous system to the creature’s saliva, ensuring that when the host bites, the virus will live on in a new carrier. But aside from rabies, stories of parasites commandeering the behavior of large-brained mammals are rare. The far more common victims of parasitic mind control—at least the ones we know about—are fish, crustaceans, and legions of insects, according to Janice Moore, a behavioral biologist at Colorado State University. “Flies, ants, caterpillars, wasps, you name it—there are truckloads of them behaving weirdly as a result of parasites,” she says.

Consider Polysphincta gutfreundi, a parasitic wasp that grabs hold of an orb spider and attaches a tiny egg to its belly. A wormlike larva emerges from the egg, and then releases chemicals that prompt the spider to abandon weaving its familiar spiral web and instead spin its silk thread into a special pattern that will hold the cocoon in which the larva matures. The “possessed” spider even crochets a specific geometric design in the net, camouflaging the cocoon from the wasp’s predators.

Flegr himself traces his life’s work to another master of mind control. Almost 30 years ago, as he was reading a book by the British evolutionary biologist Richard Dawkins, Flegr was captivated by a passage describing how a flatworm turns an ant into its slave by invading the ant’s nervous system. A drop in temperature normally causes ants to head underground, but the infected insect instead climbs to the top of a blade of grass and clamps down on it, becoming easy prey for a grazing sheep. “Its mandibles actually become locked in that position, so there’s nothing the ant can do except hang there in the air,” says Flegr. The sheep grazes on the grass and eats the ant; the worm gains entrance into the ungulate’s gut, which is exactly where it needs to be in order to complete—as the Lion King song goes—the circle of life. “It was the first I learned about this kind of manipulation, so it made a big impression on me,” Flegr says.

After he read the book, Flegr began to make a connection that, he readily admits, others might find crazy: his behavior, he noticed, shared similarities with that of the reckless ant. For example, he says, he thought nothing of crossing the street in the middle of dense traffic, “and if cars honked at me, I didn’t jump out of the way.” He also made no effort to hide his scorn for the Communists who ruled Czechoslovakia for most of his early adulthood. “It was very risky to openly speak your mind at that time,” he says. “I was lucky I wasn’t imprisoned.” And during a research stint in eastern Turkey, when the strife-torn region frequently erupted in gunfire, he recalls being “very calm.” In contrast, he says, “my colleagues were terrified. I wondered what was wrong with myself.”

His bewilderment continued until 1990, when he joined the biology faculty of Charles University. As it happened, the 650-year-old institution had long been a world leader in documenting the health effects of T. gondii, as well as developing methods for detecting the parasite. In fact, just as Flegr was arriving, his colleagues were searching for infected individuals on whom to test their improved diagnostic kits, which is how he came to be asked one day to roll up his sleeve and donate blood. He discovered that he had the parasite—and just possibly, he thought, the key to his baffling self-destructive streak.

He delved into T. gondii’s life cycle. After an infected cat defecates, Flegr learned, the parasite is typically picked up from the soil by scavenging or grazing animals—notably rodents, pigs, and cattle—all of which then harbor it in their brain and other body tissues. Humans, on the other hand, are exposed not only by coming into contact with litter boxes, but also, he found, by drinking water contaminated with cat feces, eating unwashed vegetables, or, especially in Europe, by consuming raw or undercooked meat. Hence the French, according to Flegr, with their love of steak prepared saignant—literally, “bleeding”—can have infection rates as high as 55 percent. (Americans will be happy to hear that the parasite resides in far fewer of them, though a still substantial portion: 10 to 20 percent.) Once inside an animal or human host, the parasite then needs to get back into the cat, the only place where it can sexually reproduce—and this is when, Flegr believed, behavioral manipulation might come into play.

Researchers had already observed a few peculiarities about rodents with T. gondii that bolstered Flegr’s theory. The infected rodents were much more active in running wheels than uninfected rodents were, suggesting that they would be more-attractive targets for cats, which are drawn to fast-moving objects. They also were less wary of predators in exposed spaces. Little, however, was known about how the latent infection might influence humans, because we and other large mammals were widely presumed to be accidental hosts, or, as scientists are fond of putting it, a “dead end” for the parasite. But even if we were never part of the parasite’s life cycle, Flegr reasoned, mammals from mouse to man share the vast majority of their genes, so we might, in a case of mistaken identity, still be vulnerable to manipulations by the parasite.

In the Soviet-stunted economy, animal studies were way beyond Flegr’s research budget. But fortunately for him, 30 to 40 percent of Czechs had the latent form of the disease, so plenty of students were available “to serve as very cheap experimental animals.” He began by giving them and their parasite-free peers standardized personality tests—an inexpensive, if somewhat crude, method of measuring differences between the groups. In addition, he used a computer-based test to assess the reaction times of participants, who were instructed to press a button as soon as a white square popped up anywhere against the dark background of the monitor.

The subjects who tested positive for the parasite had significantly delayed reaction times. Flegr was especially surprised to learn, though, that the protozoan appeared to cause many sex-specific changes in personality. Compared with uninfected men, males who had the parasite were more introverted, suspicious, oblivious to other people’s opinions of them, and inclined to disregard rules. Infected women, on the other hand, presented in exactly the opposite way: they were more outgoing, trusting, image-conscious, and rule-abiding than uninfected women.

The findings were so bizarre that Flegr initially assumed his data must be flawed. So he tested other groups—civilian and military populations. Again, the same results. Then, in search of more corroborating evidence, he brought subjects in for further observation and a battery of tests, in which they were rated by someone ignorant of their infection status. To assess whether participants valued the opinions of others, the rater judged how well dressed they appeared to be. As a measure of gregariousness, participants were asked about the number of friends they’d interacted with over the past two weeks. To test whether they were prone to being suspicious, they were asked, among other things, to drink an unidentified liquid.

The results meshed well with the questionnaire findings. Compared with uninfected people of the same sex, infected men were more likely to wear rumpled old clothes; infected women tended to be more meticulously attired, many showing up for the study in expensive, designer-brand clothing. Infected men tended to have fewer friends, while infected women tended to have more. And when it came to downing the mystery fluid, reports Flegr, “the infected males were much more hesitant than uninfected men. They wanted to know why they had to do it. Would it harm them?” In contrast, the infected women were the most trusting of all subjects. “They just did what they were told,” he says.

Why men and women reacted so differently to the parasite still mystified him. After consulting the psychological literature, he started to suspect that heightened anxiety might be the common denominator underlying their responses. When under emotional strain, he read, women seek solace through social bonding and nurturing. In the lingo of psychologists, they’re inclined to “tend and befriend.” Anxious men, on the other hand, typically respond by withdrawing and becoming hostile or antisocial. Perhaps he was looking at flip sides of the same coin.

Closer inspection of Flegr’s reaction-time results revealed that infected subjects became less attentive and slowed down a minute or so into the test. This suggested to him that Toxoplasma might have an adverse impact on driving, where constant vigilance and fast reflexes are critical. He launched two major epidemiological studies in the Czech Republic, one of men and women in the general population and another of mostly male drivers in the military. Those who tested positive for the parasite, both studies showed, were about two and a half times as likely to be in a traffic accident as their uninfected peers.

When I met Flegr for the first time, last September, at his office on the third floor of Charles University’s Biological Sciences building, I was expecting something of a wild man. But once you get past the riotous red hair, his style is understated. Thin and slight of build, he’s soft-spoken, precise with his facts, and—true to his Toxo status—clad in old sneakers, faded bell-bottom jeans, and a loose-fitting button-up shirt. As our conversation proceeds, I discover that his latest findings have become—to quote Alice in Wonderland—“curiouser and curiouser,” which may explain why his forehead has the deep ruts of a chronic worrier, or someone perpetually perplexed.

He’s published some data, he tells me, that suggest infected males might have elevated testosterone levels. Possibly for that reason, women shown photos of these men rate them as more masculine than pictures of uninfected men. “I want to investigate this more closely to see if it’s true,” he says. “Also, it could be women find infected men more attractive. That’s something else we hope to test.”

Meanwhile, two Turkish studies have replicated his studies linking Toxoplasma to traffic accidents. With up to one-third of the world infected with the parasite, Flegr now calculates that T. gondii is a likely factor in several hundred thousand road deaths each year. In addition, reanalysis of his personality-questionnaire data revealed that, just like him, many other people who have the latent infection feel intrepid in dangerous situations. “Maybe,” he says, “that’s another reason they get into traffic accidents. They don’t have a normal fear response.”

It’s almost impossible to hear about Flegr’s research without wondering whether you’re infected—especially if, like me, you’re a cat owner, favor very rare meat, and identify even a little bit with your Toxo sex stereotype. So before coming to Prague, I’d gotten tested for the parasite, but I didn’t yet know the results. It seemed a good time to see what his intuition would tell me. “Can you guess from observing someone whether they have the parasite—myself, for example?,” I ask.

“No,” he says, “the parasite’s effects on personality are very subtle.” If, as a woman, you were introverted before being infected, he says, the parasite won’t turn you into a raving extrovert. It might just make you a little less introverted. “I’m very typical of Toxoplasma males,” he continues. “But I don’t know whether my personality traits have anything to do with the infection. It’s impossible to say for any one individual. You usually need about 50 people who are infected and 50 who are not, in order to see a statistically significant difference. The vast majority of people will have no idea they’re infected.”

Still, he concedes, the parasite could be very bad news for a small percentage of people—and not just those who might be at greater risk for car accidents. Many schizophrenia patients show shrinkage in parts of their cerebral cortex, and Flegr thinks the protozoan may be to blame for that. He hands me a recently published paper on the topic that he co-authored with colleagues at Charles University, including a psychiatrist named Jiri Horacek. Twelve of 44 schizophrenia patients who underwent MRI scans, the team found, had reduced gray matter in the brain—and the decrease occurred almost exclusively in those who tested positive for T. gondii. After reading the abstract, I must look stunned, because Flegr smiles and says, “Jiri had the same response. I don’t think he believed it could be true.” When I later speak with Horacek, he admits to having been skeptical about Flegr’s theory at the outset. When they merged the MRI results with the infection data, however, he went from being a doubter to being a believer. “I was amazed at how pronounced the effect was,” he says. “To me that suggests the parasite may trigger schizophrenia in genetically susceptible people.”

One might be tempted to dismiss the bulk of Flegr’s work as hokum—the fanciful imaginings of a lone, eccentric scholar—were it not for the pioneering research of Joanne Webster, a parasitologist at Imperial College London. Just as Flegr was embarking on his human trials, Webster, then a freshly minted Ph.D., was launching studies of Toxo-infected rodents, reasoning, just as Flegr did, that as hosts of the parasite, they would be likely targets for behavioral manipulation.

She quickly confirmed, as previous researchers had shown, that infected rats were more active and less cautious in areas where predators lurk. But then, in a simple, elegant experiment, she and her colleagues demonstrated that the parasite did something much more remarkable. They treated one corner of each rat’s enclosure with the animal’s own odor, a second with water, a third with cat urine, and the last corner with the urine of a rabbit, a creature that does not prey on rodents. “We thought the parasite might reduce the rats’ aversion to cat odor,” she told me. “Not only did it do that, but it actually increased their attraction. They spent more time in the cat-treated areas.” She and other scientists repeated the experiment with the urine of dogs and minks, which also prey on rodents. The effect was so specific to cat urine, she says, that “we call it ‘fatal feline attraction.’”

She began tagging the parasite with fluorescent markers and tracking its progress in the rats’ bodies. Given the surgically precise way the microbe alters behavior, Webster anticipated that it would end up in localized regions of the brain. But the results defied expectations. “We were quite surprised to find the cysts—the parasite’s dormant form—all over the brain in what otherwise appeared to be a happy, healthy rat,” she says. Nonetheless, the cysts were most abundant in a part of the brain that deals with pleasure (in human terms, we’re talking sex, drugs, and rock and roll) and in another area that’s involved in fear and anxiety (post-traumatic stress disorder affects this region of the brain). Perhaps, she thought, T. gondii uses a scattershot approach, disseminating cysts far and wide, enabling a few of them to zero in on the right targets.

To gain more clarity on the matter, she sought the aid of the parasitologist Glenn McConkey, whose team at the University of Leeds was probing the protozoan’s genome for signs of what it might be doing. The approach brought to light a striking talent of the parasite: it has two genes that allow it to crank up production of the neurotransmitter dopamine in the host brain. “We never cease to be amazed by the sophistication of these parasites,” Webster says.

Their findings, reported last summer, created immediate buzz. Dopamine is a critical signaling molecule involved in fear, pleasure, and attention. Furthermore, the neurotransmitter is known to be jacked up in people with schizophrenia—another one of those strange observations about the disease, like its tendency to erode gray matter, that have long puzzled medical researchers. Antipsychotic medicine designed to quell schizophrenic delusions apparently blocks the action of dopamine, which had suggested to Webster that what it might really be doing is thwarting the parasite. Scientists had already shown that adding the medicine to a petri dish where T. gondii is happily dividing will stunt the organism’s growth. So Webster decided to feed the antipsychotic drug to newly infected rats to see how they reacted. Lo and behold, they didn’t develop fatal feline attraction. Suddenly, attributing behavioral changes to the microbe seemed much more plausible.

As the scientific community digested the British team’s dopamine discoveries, Robert Sapolsky’s lab at Stanford announced still more attention-grabbing news. The neuroscientist and his colleagues found that T. gondii disconnects fear circuits in the brain, which might help to explain why infected rats lose their aversion to cat odor. Just as startling, reports Sapolsky, the parasite simultaneously is “able to hijack some of the circuitry related to sexual arousal” in the male rat—probably, he theorizes, by boosting dopamine levels in the reward-processing part of the brain. So when the animal catches a whiff of cat scent, the fear center fails to fully light up, as it would in a normal rat, and instead the area governing sexual pleasure begins to glow. “In other words,” he says, “Toxo makes cat odor smell sexy to male rats.”

The neurobiologist Ajai Vyas, after working with Sapolsky on this study as a postdoctoral student, decided to inspect infected rats’ testicles for signs of cysts. Sure enough, he found them there—as well as in the animals’ semen. And when the rat copulates, Vyas discovered, the protozoan moves into the female’s womb, typically infecting 60 percent of her pups, before traveling on up to her own brain—creating still more vehicles for ferrying the parasite back into the belly of a cat.

Could T. gondii be a sexually transmitted disease in humans too? “That’s what we hope to find out,” says Vyas, who now works at Nanyang Technological University, in Singapore. The researchers also discovered that infected male rats suddenly become much more attractive to females. “It’s a very strong effect,” says Vyas. “Seventy-five percent of the females would rather spend time with the infected male.”

After I return from Prague, Flegr informs me that he’s just had a paper accepted for publication that, he claims, “proves fatal feline attraction in humans.” By that he means that infected men like the smell of cat pee—or at least they rank its scent much more favorably than uninfected men do. Displaying the characteristic sex differences that define many Toxo traits, infected women have the reverse response, ranking the scent even more offensive than do women free of the parasite. The sniff test was done blind and also included urine collected from a dog, horse, hyena, and tiger. Infection did not affect how subjects rated these other samples.

“Is it possible cat urine may be an aphrodisiac for infected men?,” I ask. “Yes. It’s possible. Why not?” says Flegr. I think he’s smiling at the other end of the phone line, but I’m not sure, which leaves me wondering whether I’ve stumbled onto a topic ripe for a Saturday Night Live skit, or a matter worthy of medical concern. When I ask Sapolsky about Flegr’s most recent research, he says the effects Flegr is reporting “are incredibly cool. However, I’m not too worried, in that the effects on humans are not gigantic. If you want to reduce serious car accidents, and you had to choose between curing people of Toxo infections versus getting people not to drive drunk or while texting, go for the latter in terms of impact.”

In fact, Sapolsky thinks that Toxo’s inventiveness might even offer us some benefits. If we can figure out how the parasite makes animals less fearful, he says, it might give us insights into how to devise treatments for people plagued by social-anxiety disorder, phobias, PTSD, and the like. “But frankly,” he adds, “this mostly falls into the ‘Get a load of this, can you believe what nature has come up with?’ category.”

Webster is more circumspect, if not downright troubled. “I don’t want to cause any panic,” she tells me. “In the vast majority of people, there will be no ill effects, and those who are affected will mostly demonstrate subtle shifts of behavior. But in a small number of cases, [Toxo infection] may be linked to schizophrenia and other disturbances associated with altered dopamine levels—for example, obsessive-compulsive disorder, attention-deficit hyperactivity disorder, and mood disorders. The rat may live two or three years, while humans can be infected for many decades, which is why we may be seeing these severe side effects in people. We should be cautious of dismissing such a prevalent parasite.”

The psychiatrist E. Fuller Torrey agrees—though he came to this viewpoint from a completely different angle than either Webster or Flegr. His opinion stems from decades of research into the root causes of schizophrenia. “Textbooks today still make silly statements that schizophrenia has always been around, it’s about the same incidence all over the world, and it’s existed since time immemorial,” he says. “The epidemiology literature contradicts that completely.” In fact, he says, schizophrenia did not rise in prevalence until the latter half of the 18th century, when for the first time people in Paris and London started keeping cats as pets. The so-called cat craze began among “poets and left-wing avant-garde Greenwich Village types,” says Torrey, but the trend spread rapidly—and coinciding with that development, the incidence of schizophrenia soared.

Since the 1950s, he notes, about 70 epidemiology studies have explored a link between schizophrenia and T. gondii. When he and his colleague Robert Yolken, a neurovirologist at Johns Hopkins University, surveyed a subset of these papers that met rigorous scientific standards, their conclusion complemented the Prague group’s discovery that schizophrenic patients with Toxo are missing gray matter in their brains. Torrey and Yolken found that the mental illness is two to three times as common in people who have the parasite as in controls from the same region.

Human-genome studies, both scientists believe, are also in keeping with that finding—and might explain why schizophrenia runs in families. The most replicated result from that line of investigation, they say, suggests that the genes most commonly associated with schizophrenia relate to the immune system and how it reacts to infectious agents. So in many cases where the disease appears to be hereditary, they theorize, what may in fact be passed down is an aberrant or deficient immune response to invaders like T. gondii.

Epstein-Barr virus, mumps, rubella, and other infectious agents, they point out, have also been linked to schizophrenia—and there are probably more as yet unidentified triggers, including many that have nothing to do with pathogens. But for now, they say, Toxo remains the strongest environmental factor implicated in the disorder. “If I had to guess,” says Torrey, “I’d say 75 percent of cases of schizophrenia are associated with infectious agents, and Toxo would be involved in a significant subset of those.”

Just as worrisome, says Torrey, the parasite may also increase the risk of suicide. In a 2011 study of 20 European countries, the national suicide rate among women increased in direct proportion to the prevalence of the latent Toxo infection in each nation’s female population. According to Teodor Postolache, a psychiatrist and the director of the Mood and Anxiety Program at the University of Maryland School of Medicine, a flurry of other studies, several conducted by his own team, offers further support of T. gondii’s link to higher rates of suicidal behavior. These include investigations of general populations as well as groups made up of patients with bipolar disorder, severe depression, and schizophrenia, and in places as diverse as Turkey, Germany, and the Baltimore/Washington area. Exactly how the parasite may push vulnerable people over the edge is yet to be determined. Postolache theorizes that what disrupts mood and the ability to control violent impulses may not be the organism per se, but rather neurochemical changes associated with the body’s immune response to it. “As far-fetched as these ideas may sound,” says Postolache, “the American Foundation for Suicide Prevention was willing to put money behind this research.”

Given all the nasty science swirling around this parasite, is it time for cat lovers to switch their allegiance to other animals?

Even Flegr would advise against that. Indoor cats pose no threat, he says, because they don’t carry the parasite. As for outdoor cats, they shed the parasite for only three weeks of their life, typically when they’re young and have just begun hunting. During that brief period, Flegr simply recommends taking care to keep kitchen counters and tables wiped clean. (He practices what he preaches: he and his wife have two school-age children, and two outdoor cats that have free roam of their home.) Much more important for preventing exposure, he says, is to scrub vegetables thoroughly and avoid drinking water that has not been properly purified, especially in the developing world, where infection rates can reach 95 percent in some places. Also, he advises eating meat on the well-done side—or, if that’s not to your taste, freezing it before cooking, to kill the cysts.

As concerns about the latent infection mount, however, experts have begun thinking about more-aggressive steps to counter the parasite’s spread. Inoculating cats or livestock against T. gondii might be one way to interrupt its life cycle, offers Johns Hopkins’ Robert Yolken. Moving beyond prevention to treatment is a taller order. Once the parasite becomes deeply ensconced in brain cells, routing it out of the body is virtually impossible: the thick-walled cysts are impregnable to antibiotics. Because T. gondii and the malaria protozoan are related, however, Yolken and other researchers are looking among antimalarial agents for more-effective drugs to attack the cysts. But for now, medicine has no therapy to offer people who want to rid themselves of the latent infection; and until solid proof exists that Toxo is as dangerous as some scientists now fear, pharmaceutical companies don’t have much incentive to develop anti-Toxo drugs.

Yolken hopes that will change. “To explain where we are in Toxo research today,” he says, “the analogy I always give is the ulcer bacteria. We first needed to find ways of treating the organism and showing that the disease went away when you did that. We will have to show that when we very effectively treat Toxoplasma, some portion of psychiatric illness goes away.”

But T. gondii is just one of an untold number of infectious agents that prey on us. And if the rest of the animal kingdom is anything to go by, says Colorado State University’s Janice Moore, plenty of them may be capable of tinkering with our minds. For example, she and Chris Reiber, a biomedical anthropologist at Binghamton University, in New York, strongly suspected that the flu virus might boost our desire to socialize. Why? Because it spreads through close physical contact, often before symptoms emerge—meaning that it must find a new host quickly. To explore this hunch, Moore and Reiber tracked 36 subjects who received a flu vaccine, reasoning that it contains many of the same chemical components as the live virus and would thus cause the subjects’ immune systems to react as if they’d encountered the real pathogen.

The difference in the subjects’ behavior before and after vaccination was pronounced: the flu shot had the effect of nearly doubling the number of people with whom the participants came in close contact during the brief window when the live virus was maximally contagious. “People who had very limited or simple social lives were suddenly deciding that they needed to go out to bars or parties, or invite a bunch of people over,” says Reiber. “This happened with lots of our subjects. It wasn’t just one or two outliers.”

Reiber has her eye trained on other human pathogens that she thinks may well be playing similar games, if only science could prove it. For example, she says, many people at the end stages of AIDS and syphilis express an intense craving for sex. So, too, do individuals at the beginning of a herpes outbreak. These may just be anecdotal accounts, she concedes, but based on her own findings, she wouldn’t be surprised if these urges come from the pathogen making known its will to survive.

“We’ve found all kinds of excuses for why we do the things we do,” observes Moore. “‘My genes made me do it.’ ‘My parents are to blame.’ I’m afraid we may have reached the point where parasites may have to be added to the laundry list of excuses.”

She has a point. In fact, I’ve been wondering whether T. gondii might in some small way be contributing to my extreme extroversion—why I can’t resist striking up conversations everywhere I go, even when I’m short of time or with strangers I’ll never see again. Then it occurs to me that cysts in my brain might be behind my seesaw moods or even my splurges on expensive clothes. Maybe, I think with mounting conviction, the real me would have displayed better self-control, had I not been forced to swim upstream against the will of an insidious parasite. With my feline pal Pixie on my lap (for the record, she’s an outdoor cat), I call to get the results of my Toxo test. Negative. I don’t have the latent infection.

I call to tell Flegr the good news. Even though I’m relieved, I know my voice sounds flat. “It’s strange to admit,” I say, “but I think I’m a little disappointed.” He laughs. “People who have cats often feel that way, because they think the parasite explains why they behave this way or that,” he says. “But,” I protest, “you thought the same way.” Then it hits me. I may have dodged T. gondii, but given our knack for fooling ourselves—plus all those parasites out there that may also be playing tricks on our minds—can anyone really know who’s running the show?

Valentines Day

2012-02-14T00:05:00.002-06:00

What better way to celebrate Valentines Day than an act of brotherly love? Most surprising is Diego-san actually tolerated his brother's attention for a few minutes.

On Notice

2012-02-13T00:05:00.004-06:00

Uh oh. Received a reminder from the vet that Theo's annual checkup is coming up soon. I was supposed to get his teeth cleaned last year but never got around to scheduling that appointment so I'm sure I'll hear about that this year... Where did the year go?

Black Sabbath Minus One

2012-02-12T00:00:00.002-06:00

I had to work yesterday. Diego-san seemed to agree with me that Saturdays are not days meant for work.

Palindrome

2012-02-11T00:02:00.003-06:00

Yesterday was the same backward and forward: 2/10/2012. Today not so much. I shared this factoid with Thompson and this was the look I got.

Pavlov's Cats

2012-02-10T00:12:00.004-06:00

The boyz have learned when the TV goes off, it's dinner time....

Thompson's Secret

2012-02-09T00:02:00.004-06:00

Thompson seems to be the only one in the house that knows that a sweet face goes a lot further in being able to secure a surprise treat than does mischief, howling, and waking up the treat giver at two in the morning.

Too Cool

2012-02-08T00:18:00.003-06:00

Fonzie liked to keep his comb in his back jeans pocket. Diego-san prefers to keep his comb somewhere where he can keep an eye on it. To each his own I guess.

Clarification

2012-02-07T00:25:00.001-06:00

Theo wants to know why we don't celebrate Tuxedo Tuesday in our house. I told him every day is Tuxedo Tuesday as far as I'm concerned.

Close But No Cigar...

2012-02-06T00:06:00.003-06:00

Thompson has discovered these friends aren't quite as warm as his brothers...

Super Sunday

2012-02-05T00:06:00.001-06:00

There's a football game today?

Zen Master

2012-02-04T00:06:00.001-06:00

Takes time to breath in the sun.

Enough Prep Time Already

2012-02-03T06:00:00.001-06:00

It's Friday, five days into the work/play week. Theo wants to know why everybody isn't bright eyed and bushy tailed by now...

Partners, Finally

2012-02-02T00:09:00.001-06:00

Theo and Diego-san do not often agree but here is a situation where they did find consensus. Neither one was interested in watching old baseball players talk about an old baseball game.

Don't Want to Be Prepared

2012-02-01T00:03:00.003-06:00

Ears up, eyes shut, Thompson is hoping nothing exciting goes on in the house.

Be Prepared

2012-01-31T00:09:00.002-06:00

Ears way up, eyes wide open. Now all Theo needs is for something exciting to happen in the house.

Belly Full

2012-01-30T00:12:00.003-06:00

If he wore a belt, he'd loosen it a notch...

Secret Sunday Plot

2012-01-29T00:11:00.006-06:00

Obviously Thompson has something to share with Theo that I'm not privvy too...

Laundry Day

2012-01-28T00:09:00.001-06:00

All aboard!

TGIF (LLIWARW)

2012-01-27T00:32:00.002-06:00

Thompson's glad it's Friday (looks like it was a rough week).

What's in a Nickname?

2012-01-26T00:01:00.002-06:00

Because of his massive sized paws I sometimes call Diego-san my little cuddly bear. I think he prefers to be known as a massive and ferocious black bear. Just a small difference in perspectives I guess.

Mr. Big Eyes

2012-01-25T00:01:00.003-06:00

It's the face that has launched a million smiles.

Historic Video

2012-01-24T00:09:00.006-06:00

I was fortunate to be around (with my iPhone) to capture history in the making. This is the first time I'd ever seen Theo play the role of peacemaker. His normal role is that of instigator.

What's the brouhaha all about? Diego-san was not happy that Thompson wanted him to share the sun puddle he'd been lying in all morning.

Cat Pile!

2012-01-23T00:21:00.001-06:00

Diego-san + Thompson = clump.

Junk Food Junkie

2012-01-22T00:15:00.001-06:00

Normally I have a pretty good diet. Most my meals consist of vegetables and fish. I only eat fast food a handful of times a year. Yesterday was one of those times.

I was out running some errands and I saw a KFC. I felt too tired to cook a dinner and I had been interested in the new hot wings KFC is advertising so I decided to stop in and get some. When I brought them home Diego-san's curiousity was obviously picqued by the new smell. He almost never shows any interest in the food I normally eat for dinner. I put the wings on a dish and sat down to eat and Diego-san did all he could to get a hold of one of the wings. I finally had to lock him in another room so I could eat my meal in peace.

I never knew I had a boy so interested in the worst of the worse fast food.

P.S. The wings were nothing special.

A Questioning Face

2012-01-21T00:12:00.004-06:00

Often as I leave the house Theo will run from the front door where I leave, to the side window where I walk by on the way to the garage. Sometimes the look on his face suggests a questioning on why I would want to leave the warmth and familiarity of the inside world for the vast confusion of a world he's never been allowed to explore. Not sure I have an answer for that.

To Each His Own

2012-01-20T00:12:00.000-06:00

Some think outside the box. Thompson thinks outside the bed.

Glamour Shot

2012-01-19T00:06:00.002-06:00

Can't look any handsomer.

Different Backyard

2012-01-18T00:38:00.003-06:00

We've had a very mild winter in the frozen tundra. We've barely gotten any snow, and temperatures up until the past few days had been downright balmy. Diego-san doesn't seem to mind the missing snow anymore than I do. (Although it does make it harder to tell if we have been visited by any bunny rabbits.)

A Different Type of Thinking Cap

2012-01-17T00:36:00.003-06:00

A fellow can get a lot of good thinking done when his brother is licking the back of his head.

MLK Day

2012-01-16T00:33:00.001-06:00

I'll have to teach Theo who Dr. Martin Luther King was so he has a better understanding why I get to enjoy a three day weekend with all the boyz...

Spectator's Perspective

2012-01-15T00:31:00.000-06:00

Watching Thompson watch Diego-san and Theo tussle.

Deceptive Appearance

2012-01-14T00:26:00.001-06:00

He's the light of our life...

Friday the 13th

2012-01-13T00:19:00.002-06:00

Theo is clearly not the superstititous type. He's always letting Diego-san walk in front of him (partially in preparation for chasing him all over the house)...

He's Watching You

2012-01-12T00:05:00.002-06:00

When I curl up in a ball it's to try and block out the entire world... not so with Thompson.

Bar Boy

2012-01-11T00:30:00.002-06:00

I learned 101 songs in my first year of learning guitar. Of course almost all of them sound exactly alike, similar chords and simple strumming patterns. Diego-san obviously can't wait to hear the next 100.

Life Goes On

2012-01-10T00:09:00.007-06:00

The late great Mr. Max and I lived in an apartment for several years. The best view for Mr. Max from our last apartment was out the living room window that overlooked the area behind the apartment complex. Outside our window was the biggest tree on the grounds and Max spent hours watching the birds and squirrels.

I came home one afternoon and saw that the tree had been removed. For days Max acted very lost and that memory is one of many that has stayed with me over the years. I always wonder if it was a matter of him missing the tree or if he was overwhelmingly startled by what must have been a day of very loud noise from chain saws and whatever else was used to remove such a large tree.

I got home the other night and found a notice hung on my door. The city had been out and determined that the ash tree on the boulevard was in declining health so they have decided to remove it. I have another huge ash tree in my front yard about 15 feet from the other tree, and it's in the exact same condition as far as I can tell. That the trees were nearing the end of their lives hasn't been news to me. The emerald ash borer has been found in several trees in the city and I read that the city has a plan to remove all the ash trees within the next few years.

I do wonder how the boyz will react, especially if I decide it's time to remove the ash tree in the front yard, the tree that is closest to the picture window in our living room. Diego-san and Thompson in particular love to watch the action in the tree. I would likely replace the tree with another type of tree, but it will be years before it grows tall enough for much squirrel and bird action. I just hope the boyz aren't as traumatized as Mr. Max seemed to be...

What's the Password?

2012-01-09T00:22:00.004-06:00

Theo takes his job as upstairs sentry very seriously.

Plan for Sunday

2012-01-08T00:06:00.001-06:00

Just a lotta chillin'.

Par-Tay

2012-01-07T00:05:00.001-06:00

Got a softball and a comb.... Looks like Theo has some wild plans brewing...

Lost His Pillow

2012-01-06T00:06:00.003-06:00

The problem with some warm and soft pillows is that they have a tendency after a while to get up and move somewhere else.

Simon's Cat

2012-01-05T00:10:00.001-06:00

Another Simon's Cat cartoon that Theo and Diego-san can relate to...

Resolutions Part 3

2012-01-04T00:32:00.002-06:00

Theo resolves to do his part to make our house even more entertaining in 2012.

Resolutions Part 2

2012-01-03T00:29:00.001-06:00

Diego-san indicated to me he has already given up on his 2012 resolution. As hard as he tries, he just cannot be any more handsome...

Resolutions

2012-01-02T00:22:00.006-06:00

Thompson's resolution for the new year is to sit somewhere where both ears get in the sunlight.

Happy 2012

2012-01-01T00:22:00.002-06:00

I reminded Theo to stop writing "2011" on his checks. He indicated that would not be a problem.

Brotherly Pillow

2011-12-31T00:00:00.002-06:00

Some pillows are much softer and warmer than others.

Action Position

2011-12-30T00:03:00.003-06:00

Thompson has a difficult time pouncing but he certainly is quite capable of springing into action at just about any moment...

Cuddle Face

2011-12-29T05:41:00.000-06:00

Diego-san sometimes seeks the warmth that the spotlight can't provide...

Which Way Will It Arrive?

2011-12-28T00:07:00.004-06:00

Ever since I told Theo that the new year is almost here, he's been waiting expectedly for it to arrive. Unfortunately for him I told him last week...

Wishful Thinking

2011-12-27T00:36:00.003-06:00

Given Thompson's stripes, Theo decided to see if his brother, just by chance, might taste like a candy cane...

Happy Holidays

2011-12-25T00:00:00.001-06:00

Hello! My name is Thelonious Dribble and some of you may know I’m the youngest in the house with my brothers Thompson, Diego-san and also the food fella. I feel very lucky because my housemates asked if I would do our 2011 holiday letter! Usually they don’t ask me to do anything except leave them alone… but I don’t mind because I’m up for doing anything anytime anyplace! Did I already mention anytime? For those who have never met me, come on over and visit! I love to meet new people. In the meantime the next best thing you can do is listen to the squeaky bathroom door at the food fella’s work because he said it sounds just like my MEOW! It reminds him of home where I try to follow him into the bathroom and I cry and cry until he finally opens the door!

This past year was a very special year for us because we got a tent for Christmas and the food fella made sure it was stocked with nip toys all year. There’s nothing I love more than licking my nip banana. Unless it’s licking my nip fish! Or my nip stick of dyno-mite! Sometimes Thompson or Diego-san will grab one of the toys from the tent but usually they just go away when I join them in licking the toy! Our house motto is it’s good to be licked every now and then!

Thompson is a pretty good big brother. He likes to wrestle and growl at me. He usually spends his day sleeping in the living room and sometimes I’ll even join him for a nap. But not for long. Because I’m on the go! Got things to do!

I look up to my other brother, Diego-san, a lot. And not just because when I chase him he likes to jump up somewhere I can’t jump up to! He howls and hisses at me and I know he just would love if I could jump as high as him! His are loving whaps on the top of my head!

The newest thing in our house this year was the food fella trying to learn how to play what he calls a gee-tar! It’s very loud and it’s even louder when he does what he calls singing and my brothers and I call CAT-erwalling! Diego-san sits next to him when he practices his gee-tar but Thompson and I usually stay downstairs until the racket is finally over. You think with all the time he practices he would get better. We’re all crossing our paws! (Thompson uses his back paws to cross!) If it’s not the noise from the gee-tar it’s the noise he makes telling us all about the ringing he hears in his ear. Sometimes when I sit on his chest he asks if I can hear the ringing. When I butt my head against his head I do hear the wind whistling in one ear and out the other! But that’s definitely more of a whistle then a ring though so I’m not sure I know what he’s talking about just like most other stuff.

Well I hope you liked my letter. I have to get going. I gotta look for some food or play with my brothers. Or look for some food. I hope y’all have a great holiday full of nip and fun! Oh and by the way, my food dish is empty!

XXOO,

Theo, Thompson, Diego-san, and DMa

On the Ball

2011-12-24T00:27:00.003-06:00

Thompson has claimed a choice spot to await for Santa's arrival...

Sunny Side Up

2011-12-23T00:03:00.002-06:00

Diego-san demonstrates he's in the holiday spirit by happily rolling over in the sun. He hopes all cats in the world are so lucky...

Double Wide Shower

2011-12-22T00:00:00.001-06:00

Theo is glad the showering area is large enough for two; I'm not so sure Thompson agrees.

Wise Guy

2011-12-21T00:06:00.003-06:00

I do believe that Diego-san is sticking his tongue out at the photographer. Little does he know that Santa doesn't deliver to wise guys.

Hats Off

2011-12-20T00:07:00.001-06:00

Thompson just shakes his head at some of the silly stuff I put on top of my head...

Ear Positioning

2011-12-19T00:08:00.002-06:00

Must be nice to be able to hear stuff off to the left at the same time you are listening to stuff in front of you. Then again, maybe that's why Theo usually has a puzzled look on his face...

Shades

2011-12-18T00:08:00.003-06:00

Rather than buy a fancy pair of sunglasses, I decided using Diego-san to block out sunlight was a more appealing option.

Allez Cuisine

2011-12-17T00:15:00.004-06:00

The boyz are sending out a big thank you to Daisy the curly cat. After reading how much she and her brother Harley enjoy bonito flakes, I decided to try some. Not only for the boyz, but also for myself since being a fan of the TV show, "Iron Chef," I knew that Iron Chef Michiba used bonito flakes as a staple of many of his dishes.

We got our first shipment of bonito this week and as soon as I opened the package all three boyz came into the kitchen with eyes wide open. I put a little in their dinner dishes and they couldn't snarf it down fast enough. I have yet to try using it in my cooking, but the boyz thank Daisy for introducing such a tasty treat into the house....

Playful T

2011-12-16T00:02:00.003-06:00

One word that rarely describes Thompson is "playful." Playing with cat toys is challenging because to do it upright means trying to time batting the toy with hopping to maintain balance. Usually when he plays he does so on his side and often substitutes his back paws or his nose for his missing front leg. Last night for some reason he was in an extra playful mood, hiding inside the empty spot in one of our cat scratchers and then later batting the ball around in this toy. I didn't have my camera handy and just caught the last moments of playtime. Somehow though, to see Thompson play ALWAYS makes me feel happy.

No to Muppetry

2011-12-15T00:09:00.001-06:00

I went to see the new Muppet movie. I told Diego-san afterward that because there doesn't appear to be any feline muppets that perhaps he ought to sign up. He was not amused.

Zen-like Chaos

2011-12-14T00:07:00.004-06:00

Things couldn't get any wilder on a Wednesday...

Last Line of Defense

2011-12-13T00:04:00.001-06:00

Theo finds himself in the challenging situation of being the last thing standing (or laying) between the sun and the laundry basket.

Choices

2011-12-12T00:08:00.002-06:00

Diego-san indicated it was too bad I had to spend my day at work earning money to feed and house him. For him, lying on his back in the sun sounds far better.

Possible Overtime Required

2011-12-11T00:01:00.003-06:00

It's been a busy Sunday for Thompson. He's already had to change positions on the couch three times.

Spokescat

2011-12-10T00:09:00.000-06:00

We've asked Theo to write this year's annual holiday card for friends and family. He's taking the responsibility seriously, pondering what he should write about by guarding the chase the mouse in the circle toy. It's how he gets his best thinking done.

An Occasional Difference or Two

2011-12-09T00:12:00.004-06:00

Although they usually get along pretty well, Thompson and Theo don't always see things eye to eye.

Don't Be Fooled

2011-12-08T00:19:00.002-06:00

He may not always look like it in his pictures but Diego-san is a pretty soft and cuddly guy.

Strengths

2011-12-07T00:05:00.006-06:00

Diego-san might be the most intelligent and Theo might be the most determined, but Thompson is the wisest boy. He's very good at assessing a situation, determining if he wants to be involved and then getting what he wants.

Our Lil Conservationist

2011-12-06T00:04:00.003-06:00

Given the trickle from the faucet, Theo was worried that we are running out of water until I reassured him that I would dilute the supply we have to make it last longer.

Sympathizer

2011-12-05T00:13:00.000-06:00

Thompson showed which side he was on after I hollered at Diego-san for jumping up in the kitchen sink and licking all the dirty dishes...

A Cartoon Depiction - Simon's Cat

2011-12-04T00:08:00.002-06:00

This is exactly like Theo and Diego-san's ever uneasy relationship...

Psssst...

2011-12-03T00:07:00.001-06:00

Hey Diego-san... there appears to be some worms, or a shadow of a turkey on the ground in front of you...

Theo the Artist

2011-12-02T00:12:00.005-06:00

Not all of us have the artistic soul of Theo- here he tries to dramatize his black and white coloring with the use of darkness and light. Either that or he just forgot to move when the sun did.

Thompson's Thought for the Day

2011-12-01T00:26:00.001-06:00

We all need someone to look up to (especially if he can provide some food).

Priorities, Man

2011-11-30T00:06:00.000-06:00

Diego-san was more interested in giving me the evil eye than he was watching the Muppet Show.

Two Out of Three Ain't Bad

2011-11-29T00:07:00.005-06:00

Theo was practicing the part of the Big Bad Wolf from Little Red Riding Hood. He definitely got the big ears (better to hear you), and the big eyes (better to see you) down, but his teeth are tiny and probably wouldn't scare Little Red Riding Hood much.

Good Question

2011-11-28T00:08:00.002-06:00

Thompson wonders why every weekend can't be a four day weekend.

Good Help is Hard to Find

2011-11-27T00:04:00.002-06:00

Diego-san was going to point out to the cleaning guy that he missed something but that would probably mean the big old noisy sucking machine would have to make a reappearance...

Premium Seats

2011-11-26T00:01:00.001-06:00

Diego-san tried to scalp his ticket to me but I passed. So he was the one who got to enjoy the front row to all the action.

Tuxedo Friday

2011-11-25T00:08:00.002-06:00

Yup, today tastes like the day after Thanksgiving.

Happy Thanksgiving

2011-11-24T00:06:00.002-06:00

Among many other things, Thompson is thankful he has many comfortable places to lay his head.

Reporting for Duty

2011-11-23T00:20:00.005-06:00

We got our first snowfall over the weekend. It was just enough snow that I felt obligated to shovel the public sidewalk in front of my house. As I was preparing to go outside, Diego-san was being extra needy of attention so I told him I could use a little help shoveling and suggested I let him go outside and swish his impressive tail around to clear the snow. I certainly couldn't lose him in the snow given his color.

As I went to the front door Diego-san hopped up on the bookcase next to the door as if to indicate he was willing to try what I suggested. Alas, I changed my mind and decided it probably wasn't a good idea to use him as my snow swisher.

Math Tutors

2011-11-22T00:18:00.005-06:00

The boyz decided to help me with my geometry by showing me what a cat triangle looks like.

Sunny Day

2011-11-21T00:08:00.001-06:00

All paws in.

A Personal Trainer

2011-11-20T00:05:00.002-06:00

Thompson wants to emphasize the importance of regular neck exercises. First you look one way, then you turn your head the other way. Repeat and zzzzzzzzzzz.......

Diego-san's Haiku

2011-11-19T00:03:00.002-06:00

The sun is shining
but maybe only on me
we are best of friends

House Motto

2011-11-18T00:09:00.002-06:00

Sometimes we all just need a good licking.

Disappointment

2011-11-17T00:07:00.002-06:00

I told Theo there was a mouse by the computer. Hard as he tried, he just couldn't find it...

We All Agree

2011-11-16T00:19:00.002-06:00

Thompson's thinking the fella on the other side is pretty darn good lookin.

Mr. Know It All

2011-11-15T00:04:00.002-06:00

Diego-san's secret for knowing EVERYTHING that goes on in the house? He keeps one ear to the ground.

Planning for the Future

2011-11-14T00:10:00.001-06:00

Theo's practicing his behind the wheel driving position for the day I let him take driver's ed.

Misleading Caption

2011-11-13T00:01:00.002-06:00

Thompson is questioning how he got the title, 'cat scratcher.' He said he doesn't itch any more than the other two boyz.

Life on the Other Side of the Tracks

2011-11-12T00:07:00.001-06:00

Life is so hard for Diego-san. It's hard to know which of the twenty choice spots in the house to rest in ; it's hard to choose whether to lie sunny side up, or over easy; it's hard to choose whether to try and steal Thompson's dinner or Theo's dinner after he finishes his own. Sigh.

11/11/11

2011-11-11T00:04:00.001-06:00

This is the second day in the current month where Thompson feels it is appropriate to try and be one with the world.

An Endorsement

2011-11-10T00:01:00.003-06:00

Sunlight not only feels good, but it smells good too.