Integration of Hetero Inputs to Guinea Pig Auditory Cortex Established by Fear Conditioning
The present study used an optical imaging paradigm to investigate plastic changes in the auditory cortex induced by fear conditioning, in which a sound (Conditioned Stimulus, CS) was paired with an electric foot-shock (Unconditioned Stimulus, US). We report that, after conditioning, auditory information could be retrieved on the basis of an electric foot-shock alone. Before conditioning, the auditory cortex showed no response to a foot-shock presented in the absence of sound. In contrast, after conditioning, the mere presentation of a foot-shock without any sound succeeded in eliciting activity in the auditory cortex. Additionally, the magnitude of the optical response in the auditory cortex correlated with variation in the electrocardiogram. The area activated in the auditory cortex, in response to the electric foot-shock, also showed a considerable correspondence to that elicited by the CS sound. These results suggest that integration of different sensory modalities in the auditory cortex was established by fear conditioning.
KeywordsPyramidal Neuron Fear Conditioning Auditory Cortex Basal Forebrain Medial Geniculate Body
This work was supported by the twenty-first Century Center of Excellence (COE) Program and the Global COE Program at Tamagawa University and Grants-in-Aid for Scientific Research (A) 19200014, Young Scientists (B) 21700435 and Scientific Research on Innovative Areas 21120006 from MEXT in Japan.
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