Studying bacteria can improve neurobiologists' understanding of the human mind, Daniel E. Koshland, professor of biochemistry at the University of California, said last night.

Koshland told a capacity audience in Science Center B that bacteria responds to its environment in much the same way as the neurons of the brain react to their surroundings.

He explained that the human mind contains so many neurons that direct observation of neuron behavior is difficult.

Bacteria behave in certain patterns, Koshland said. "They are attracted and repelled by certain things just as human beings are."

"For example, if I smell Chanel No. 5, I'm attracted," he added.

Mark Spitz

Koshlan explained that biochemists are able to determine how bacteria are feeling by observing their paths in microscopes. Bacteria that are in supportive environments tend to swim in smooth paths, while bacteria in "obnoxious" environments, repelled by chemicals or extreme temperatures, "tumble" as they travel.

Koshland said his experiments indicate bacteria are able to remember past experiences just as human beings can. By observing their tumbling activities, he discovered that the memory of bacteria is very sophisticated, including both long and short-term recall.

Koshland said that there is some evidence that psychological diseases, including schizophrenia, are caused by reactions of the individual neurons of the brain to chemicals. Neurons, he said, may react to chemical imbalances to create behavioral disorders.

Koshland said psychological diseases are also influenced by hereditary and environmental factors. A person with a biochemical lesion, which usually causes schizophrenia, might avoid the disease if he were brought up in a tranquil environment.

Bacteria do respond to alcohol, Koshland said. He added, "It's bad for them in the same way it's bad for us--only there's no evidence that they get hangovers."