Some key parameters in contextual fear conditioning and extinction in adult rats

In this study we evaluated the effects of the number of sessions, the number of unconditioned stimuli per acquisition session and the distribution of extinction sessions to assess fear acquisition and extinction and determine under which conditions generalization occurred in adult, male rats. We observed that the organization and spacing of sessions were relevant factors in the acquisition and extinction of contextual fear memories. Extinction occurred with significantly greater robustness when sessions were spread over two days. Furthermore, results indicated that exposure to a single 0.3 mA, 0.5 s footshock in two different sessions could produce context-specific fear, while more acquisition sessions or more footshocks within a single session produced a generalization of the fear response to a new context. Notably, when generalization occurred, successive re-exposure to the generalized context produced extinction in a similar way to the paired exposure. Together, the present findings identify clear procedural and behavioral parameters amenable to neural systems analysis of three clinically relevant outcomes of contextual fear conditioning, i.e., memory acquisition, storage and extinction.PMID:38266780 | DOI:10.1016/j.bbr.2024.114874

Source: Behavioural Brain Research - January 24, 2024 Category: Neurology Authors: M ónica Navarro-Sánchez Isis Gil-Miravet Daniel Montero-Caballero Esther Castillo-G ómez Andrew L Gundlach Francisco E Olucha-Bordonau Source Type: research