Responses of amygdala single units to odors in the rat

Single unit activity was recorded from the cortical, medial, and basal nuclei of the amygdala of anesthetized rats during controlled presentation of odor stimuli. Some of the odors were derived from volatile organic compounds, while others consisted of the odor of natural substances. The odors elicited responses in 46% of cortical nucleus units, in 42% of basal nucleus units, and in a smaller proportion (21%) of medial nucleus units. In samples of hippocampal and cortical single units also tested for response to odors, 33% of hippocampal units responded, while no cortical units responded. These results are consistent with the general idea that the amygdala has some role in the processing of odors that are important in many species-typical actions. However, no support was found for the hypothesis that certain amygdala units respond exclusively to particular natural odors.