A few interesting bits about the brain that I've seen the past few weeks...
First, contrary to long-held popular belief, adult brain cells do keep growing. So you can teach an old brain new tricks. Furthermore, it seems that a marijuana-like drug can accelerate neurogenesis, and may have anti-anxiety and anti-depressive effects. (Despite what the SSRI-pushers claim, the anti-depressant effects of drugs like Prozac, Zoloft and Paxil apparently have more to do with neurogenesis than with correcting some "chemical imbalance".)
Secondly, new brain cells follow the flow of cerebrospinal fluid (CSF). This should be very interesting to people who practice craniosacral therapy. It also puts me in mind of a suggestion I heard several years ago that mild depressive symptoms and irritability can result from chronic mild dehydration; if depression is linked to neurogenesis, and new neurons need a good flow of CSF to get around to where they need to be in your brain, maybe a little more water can help keep your brain wet and healthy. So drink up. ("I ain't sayin' that you oughta, it's water, you gotta".)
Thirdly - the really weird one. The Straight Dope covers the link between protozoan Toxoplasma gondii - a parasite found in cat shit - and schizophrenia:
Forty-five percent of schizophrenics tested positive in one study for both T. gondii and D-lysergic acid diethylamide, better known as LSD. To quote a recent paper: "These results support the hypothesis that T. gondii may cause schizophrenia and may do so by producing or triggering the production of an hallucinogenic chemical...Production of such a compound may have been favored by natural selection because an infected, hallucinating rodent would be more easily captured by a cat." In other words, schizophrenia in humans may be a side effect of T. gondii's attempt to set cats up with a steady supply of tripping mice, the better to ensure its own reproductive success. Told you this was bizarre.
Uncle Cecil notes that roughly a third of all humans are infected, with the rate in some tropical countries approaching 100 percent; since we're not all hearing the voices, obviously there's more than just the presence of the protozoan involved. Still, wacky stuff. Stay away from the cat poop. (Especially if you're a pregnant woman - T. gondii can cause lethal brain damage in the fetus.)