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Theoretical Leap. Many researchers feel that memories are stored and recalled by a combination of macromolecules or large molecules that probably differ considerably from one individual to another. Thus they reject the notion of some science-fiction writers that memory molecules—and thereby memories—may one day be transferred from one brain to another. "The immune response is a learned reaction," says Rockefeller University's Edelman, again citing the parallel between memory and immunology. "There is no Marcel Proust for immunology. I doubt that there's one for the neurosciences."
While focusing down on individual cells in the course of their investigations into the grand scheme of the brain, neuroscientists—like the Persian fairy tale's three princes of Serendip—have been making fortuitous discoveries that have already resulted in improved clinical treatment of several serious illnesses.
Among them:
SCHIZOPHRENIA. Doctors know that two groups of drugs, which include chlorpromazine and haloperidol, are remarkably effective in relieving the thought disorders, hallucinations and extreme withdrawal of schizophrenia, a chronic psychosis that affects one person out of every 100. Both drugs, if administered in excess, can produce symptoms similar to those of Parkinson's disease, a neurological disorder characterized by uncontrollable tremors and lack of coordination. Parkinson's disease is caused by a lack of dopamine, a substance that transmits nerve impulses, in the brain centers that coordinate movement. Biochemical and electrophysiological studies have shown that chlorpromazine and haloperidol block the action of dopamine. Thus brain researchers suspect that schizophrenia results, at least in part, from an excess of dopamine.
Another clue to schizophrenia, says Dr. Seymour Kety, chief of the psychiatric research laboratories at Massachusetts General Hospital, lies in the discovery of an enzyme in the brains of both animals and man that can convert normal brain chemicals like tryptamine to dimethyltryptamine, a well-known hallucinogen. Kety and other scientists speculate that in schizophrenics such a process may be out of control.
DEPRESSION. Some severe psychiatric illnesses can now be controlled chemically. Researchers have theorized that depression may result when certain brain substances called monoamines are either lacking or are broken.down too quickly. A new class of drugs neutralizes monoamine oxidase (MAO), the enzyme that destroys these substances. The drugs, known as MAO inhibitors, thus prolong the useful life of the monoamines in the brain. The drugs by themselves are not considered a cure for depression, but they can give relief to the victim of acute depression while psychotherapy attempts to get at the root of his problem.