From chemotaxis to neuroscience

It may seem that bacterial behavior has little connection to neuroscience, but the connection is quite deep. Anyone who studied bacterial chemotaxis was astonished how complex, sensitive and robust this molecular machinery is, and by the fact that bacteria sense, process the sensory cues, and make behavior/motor decisions which appear to be quite optimal under the constrains of the world they live. One can’t help but wonder if bacteria think in some primordial way, that is: sense, process the information, and make decisions to improve one’s chances of survival.

On the other extreme, neuroscience studies the enormously complex human brain, and (sometimes) tries to explain what the intelligence is. Various degrees of intelligence are inherent to all animals and perhaps simple organisms. If intelligence is the ability to sense and process information to make optimized decisions, why stop at animals? In the spectrum of creatures that possess some intelligence, bacteria are even not the dumbest ones - certainly above the level of viruses. The question on the nature of intelligence is as old and deep as the question of what is a live organism, and hard boundaries are difficult to draw in either of them.