Is there a universal neural code for sensation, similar to the genetic code, in which the complexity of sense and experience can be reduced to a few simple rules? According to Prof. Ehud Ahissar of the Weizmann Institute's Neurobiology Department, who studies how rats use their whiskers to sense their environment, the answer might be no.
To get a fix on their surroundings, rats whisk their whiskers back and forth as they move about. But how does the rat's brain map out a three-dimensional object using this movement? Sensing begins in the neurons at the whisker bases, which then fire signals off to the brain. The scientists, Marcin Szwed, Knarik Bagdasarian and Ahissar, found that the neurons encode information in a completely different form when perceiving each of the three dimensions in the rat's immediate surroundings - the horizontal, the vertical and the radial (distance from the whisker base). In other words, three different types of code are involved in the seemingly simple act of feeling out a three-dimensional object.
Prof. Ehud Ahissar's research is supported by the Nella and Leon Benoziyo Center for Neurosciences; the Carl and Micaela Einhorn-Dominic Institute for Brain Research; the Irving B. Harris Foundation; the Edith C. Blum Foundation; and Ms. Esther Smidof, Switzerland. Prof. Ahissar is the incumbent of the Helen Diller Family Professorial Chair in Neurobiology.