Fornix-fimbria section and the partial reinforcement extinction effect.
Rats were trained to run in an alley for food reward given on every trial (continuous reinforcement, CR) or on a random 50% of trials (partial reinforcement, PR) and were then extinguished. Sham-operated controls showed the normal partial reinforcement extinction effect (PREE), in that PR-trained animals were significantly more resistant to extinction than CR-trained animals. The PREE was significantly reduced by lesions of the fornix-fimbria. The reduction was largely a consequence of a reduction in resistance to extinction in PR-trained rats with fimbria-fornix lesions. These results are discussed in the light of other experiments that have studied disconnections in the septo-hippocampal system.
D000818:Animals; D001522:Behavior, Animal / Q000502:physiology*; D005108:Extinction, Psychological; D006624:Hippocampus / Q000503:physiopathology*; D008297:Male; D010805:Physical Conditioning, Animal; D051381:Rats; D011919:Rats, Inbred Strains; D012055:Reinforcement Schedule; D012686:Septal Nuclei / Q000503:physiopathology