Scientists have recently discovered that a microbial parasite may be making people schizophrenic. (Link). It seems that the parasite, Toxoplasma gondii, has evolved to live in cats and rats. In cats, it sheds eggs that are eaten by rats. The rats remain perfectly healthy… almost. There is a subtle but important effect: whereas uninfected rats are terrified by the smell of cat urine, infected rats are attracted to it, making them convenient meals for felines, and so the parasite completes its life cycle.
Toxoplasma gondii also infects three billion humans--half the people on the planet. It damages astrocytes, cells in the brain that have been found to be damaged in schizophrenics. High levels of antibodies to Toxoplasma in pregnant women mean that their children are more likely to develop schizophrenia. And in cell cultures, growth of Toxoplasma is stopped by haldoperidol (Haldol), an anti-psychotic drug. Haldol also restores infected rats’ fear of cat urine; it’s as effective as Toxoplasma-specific antibiotics.
If microbes can cause schizophrenia in humans, risky behavior in rats, and gymnastics in ants (also described in the Yahoo article), then we still have a lot to learn about how to be healthy. We have had microscopes for hundreds of years, but it takes more than microscopes to discover links between microbes and illness. There are hundreds of different kinds of microbes in the human body, and most of them are harmless (as far as we know). What we need is to be able to get down to the biochemical level with broad-spectrum chemical probes, diagnostic devices small enough to be safely implanted in living humans, real-time DNA and protein analysis, and computers powerful enough to analyze massive reams of information and look for useful patterns.
Medical research is advancing rapidly, and the next ten years may see a number of new discoveries based on early versions of microbe-analyzing tools. But molecular manufacturing could make it a lot easier to do such research. Vastly more powerful computers, smaller and more numerous sensors, and molecular analysis tools that can be reshaped for each molecule of interest, should make it a lot more practical to learn exactly what our microbe companions are doing to us.
Mike Treder is a fellow of the IEET, and the Executive Director of the non-profit
Center for Responsible Nanotechnology, an organization working to raise awareness of the issues presented by advanced nanotechnology.
IEET Blog