Extinction learning, which consists of the inhibition of retrieval, can be learned without retrieval

• DOI: 10.1073/pnas.1423465112
• Publication Date: 2014-12-31T02:59:56Z
• Authors: Jociane de Carval...; Cristiane Regina ...; Bianca Schmidt; Flávia Ferreira; Ivan Izquierdo
• Keywords: Male; Protein Synthesis Inhibitors; Sirolimus; Muscimol; Models, Neurological; Fear; Models, Psychological; Extinction, Psychological; Rats; 03 medical and health sciences; 0302 clinical medicine; Conditioning, Psychological; Animals; Learning; GABA-A Receptor Agonists; Rats, Wistar; CA1 Region, Hippocampal; Anisomycin

Significance Blockade of the retrieval of contextual fear conditioning by intrahippocampal muscimol administration does not impede extinction of the task measured up to 1 wk later, its eventual spontaneous recovery at 14 d, or its inhibition by two different protein synthesis inhibitors given into the hippocampus. These results show that extinction and retrieval are separate processes and strongly suggest that extinction is triggered or gated by the conditioned stimulus even in the absence of retrieval.