Induction of receptive field plasticity in the auditory cortex of the guinea pig during instrumental avoidance conditioning.
Classical tone conditioning shifts frequency tuning in the auditory cortex to favor processing of the conditioned stimulus (CS) frequency versus other frequencies. This receptive field (RF) plasticity is associative, highly specific, rapidly acquired, and indefinitely retained-all important characteristics of memory. The investigators determined whether RF plasticity also develops during instrumental learning. RFs were obtained before and up to 24 hr after 1 session of successful 1-tone avoidance conditioning in guinea pigs. Long-term RF plasticity developed in all subjects (N = 6). Two-tone discrimination training also produced RF plasticity, like classical conditioning. Because avoidance responses prevent full elicitation of fear by the CS, long-term RF plasticity does not require the continual evocation of fear, suggesting that neural substrates of fear expression are not essential to RF plasticity.
Bakin
J S
JS
Department of Psychobiology and Center for the Neurobiology of Learning and Memory, University of California, Irvine 92697-3800, USA.
South
D A
DA
Weinberger
N M
NM
D000818:Animals; D001245:Association Learning / Q000502:physiology; D001303:Auditory Cortex / Q000502:physiology*; D001362:Avoidance Learning / Q000502:physiology*; D003214:Conditioning, Classical / Q000502:physiology*; D003216:Conditioning, Operant / Q000502:physiology*; D005072:Evoked Potentials, Auditory / Q000502:physiology; D005239:Fear / Q000502:physiology; D006168:Guinea Pigs; D008297:Male; D011939:Mental Recall / Q000502:physiology; D009473:Neuronal Plasticity / Q000502:physiology*; D009474:Neurons / Q000502:physiology; D010897:Pitch Discrimination / Q000502:physiology