The role of nucleus accumbens shell in learning about neutral versus excitatory stimuli during Pavlovian fear conditioning.
We studied the role of nucleus accumbens shell (AcbSh) in Pavlovian fear conditioning. Rats were trained to fear conditioned stimulus A (CSA) in Stage I, which was then presented in compound with a neutral stimulus and paired with shock in Stage II. AcbSh lesions had no effect on fear-learning to CSA in Stage I, but selectively prevented learning about the neutral conditioned stimulus (CS) in Stage II. These results add to a growing body of evidence indicating an important role for the ventral striatum in fear-learning. They suggest that the ventral striatum and AcbSh, in particular, directs learning toward or away from a CS as a consequence of how well that CS predicts the shock unconditioned stimulus (US). AcbSh is required to reduce the processing of established predictors, thereby permitting neutral or less predictive stimuli to be learned about.
Bradfield
Laura A
LA
School of Psychology, The University of New South Wales, Sydney 2052, Australia.
McNally
Gavan P
GP
D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects; D003214:Conditioning, Classical / Q000187:drug effects / Q000502:physiology*; D004597:Electroshock / Q000009:adverse effects; D018690:Excitatory Amino Acid Agonists / Q000494:pharmacology; D005239:Fear; D046352:Freezing Reaction, Cataleptic / Q000187:drug effects / Q000502:physiology; D016202:N-Methylaspartate / Q000494:pharmacology; D009714:Nucleus Accumbens / Q000187:drug effects / Q000293:injuries / Q000502:physiology*; D051381:Rats
D018690:Excitatory Amino Acid Agonists; D016202:N-Methylaspartate