Drugs that encourage the growth of new neurons in the brain are now headed for clinical trials.
In the last ten years, scientists have discovered that new neurons are born in the adult brain and that increases or decreases in this cell growth may be involved in myriad brain diseases, including depression, schizophrenia and stroke. Subsequent research has shown that existing drugs, including Prozac and other antidepressants, boost neurogenesis. In fact, that property may be an integral component of the drugs' effectiveness -- for example; some experiments suggest that new cell growth in the hippocampus is necessary for antidepressants to work.
Clinical trials of the company's lead candidate, known as BCI-540, began earlier this year. The drug, originally developed for Alzheimer's disease, boosts brain cell growth by 20 percent. Schoeneck says the drug has so far shown no signs of gastrointestinal or sexual side effects, two of the most problematic side effects of current antidepressants.
Drugs that boost brain cell growth may also aid cognition. Previous research has shown that neurogenesis in the hippocampus, a brain area integral to learning and memory, is important for maintaining plasticity in that part of the brain, which in turn is linked to memory function. "With aging, there's a decrease in neurogenesis," says Kriegstein. "The hypothesis is that if you could boost neurogenesis to compensate for that age-related decline, you might maintain functional levels."
BrainCells is also testing a compound, known as BCI-632, for its cognitive enhancing properties. "It's the most neurogenic compound we've seen," says Schoeneck. While the compound hasn't yet been tested in humans, it appears to boost at least one type of memory in rodents. The company aims to begin clinical trials next year.
They start out as industrial yeast or nonpathogenic strains of E. coli, but LS9 modifies them by custom-designing their DNA. Because crude oil is only a few molecular stages removed from the fatty acids normally excreted by yeast or E. coli during fermentation, it does not take much fiddling to get the desired result.
Using genetically modified bugs for fermentation is essentially the same as using natural bacteria to produce ethanol, although the energy-intensive final process of distillation is virtually eliminated because the bugs excrete a substance that is almost pump-ready.
"Our plan is to have a demonstration-scale plant operational by 2010 and, in parallel, we'll be working on the design and construction of a commercial-scale facility to open in 2011," says Mr Pal, adding that if LS9 used Brazilian sugar cane as its feedstock, its fuel would probably cost about $50 a barrel.