The Relationship between Prefrontal Cortex Neuron Activity in the Two Hemispheres on Performance of a Choice Task in a Two-Ring Maze

Abstract

Neuron activity in two symmetrical areas of the prefrontal cortex in the left and right hemispheres of the rat brain (55 and 47 neurons, respectively) was recorded as the animals performed a behavioral choice task in a two-ring maze. Experiments were performed in two sets of conditions – i) working with a conditioned signal, when excursions to the side indicated by the signal were reinforced, and ii) without a signal, when any excursion was reinforced. The levels of involvement of a neuron in different steps of the behavioral program were evaluated in terms of the level of differential activity, i.e., differences in neuron activity in right- and left-sided performances. In conditions in which the animal took the decision without orienting itself to external signals (in two behavioral situations: working without signals and erroneous performance of the program), there was a predominance of differential activity in the left hemisphere. In correct performances of the program, activity dominated in the right hemisphere. This appears to be evidence of a consistent dynamic in the interaction between the hemispheres depending on external and internal conditions and the special role of the right hemisphere in learning mechanisms and inclusion of the external determinant in the adaptive response system.