Optical Imaging of Plastic Changes Induced by Fear Conditioning in The Auditory Cortex of Guinea Pig

Abstract

In this study, the plastic change in the auditory cortex induced by a fear conditioning with pairing of sound (Conditioned Stimulus, CS) and electric foot-shock (Unconditioned Stimulus, US) was investigated by using of an optical recording. To investigate the effect of association learning, optical signals in the auditory cortex to CS (12 kHz pure tone) and non-CS (8 and 16 kHz pure tone) were recorded before and after the conditioning. As a result, the response area only to CS increased after the conditioning. On the other hand, to investigate whether auditory information could be retrieved by electric foot-shock after association learning or not, auditory response to foot-shock was also investigated before and after the conditioning. As a result, the optical response in the auditory cortex to only electric foot-shock without any sound stimuli could not be observed before the conditioning but clearly appeared after the conditioning.