Changes in the sensory response of single cells in the septal area following repeated sensory stimulation

Abstract

The influence of previous sensory experience on the sensory response of single cells in the septal area was examined. Previous electrophysiological and behavioral research is congruent with the possibility that the response of cells in the septal area to sensory stimuli changes as a function of previous sensory experience. The experiment tested the hypothesis that the response of cells in the septal area to a sensory stimulus changes as a function of previous experience with that stimulus. The experiment also tested the hypothesis that the response of these cells changes as a function of the animal's previous experience with non-modality-specific information. The rate of firing of single cells in the septal area was measured during repeated presentations of noise bursts and light flashes. To test the hypothesis that the response to a stimulus changes as a function of experience with the stimulus, the response of septal neurons was noted for each of 28 presentations of one of the stimuli. For seventy-eight (88 percent) of the 90 recorded cells the response to the stimulus changed appreciably after repeated exposures. To test the hypothesis that the response changes as a function of experience with non-modality-specific information, the response of cells in the septal area to one of the stimuli was recorded before and after repeated presentations of the other stimulus. It was maintained that changes in response following presentations of a stimulus from a second sensory modality are the result of experience with non-modality-specific sensory information. Thirty-six (84 percent) of 43 cells recorded with this procedure responded differently to a stimulus following the repeated presentation of a stimulus from a second sensory modality. The relevance of the results to the understanding of the sensory and behavioral functions of the septal area was noted.