2026-04-17T06:58:42Zhttps://recercat.cat/oai/request

oai:recercat.cat:2072/4718532025-05-08T14:51:34Zcom_2072_98col_2072_378192

00925njm 22002777a 4500 dc Tapias-Espinosa, Carles author Kádár, Elisabet author Segura Torres, Pilar author Universitat Autònoma de Barcelona. Institut de Neurociències author 2018 Extinction-based therapies (EBT) are the psychological treatments of choice for certain anxiety disorders, such as post-traumatic stress disorder. However, some patients relapse and suffer spontaneous recovery (SR) of anxiety symptoms and persistence of avoidance behaviour, which underlines the need for improving EBT. In rats, recent evidence has highlighted the relevance of the temporal distribution of extinction sessions in reducing SR of auditory fear conditioning, although it has seldom been studied in procedures involving proactive avoidance responses, such as two-way active avoidance conditioning (TWAA). We examined whether the temporal distribution of two extinction sessions separated by 24h or 7days (contiguous versus spaced extinction paradigms, respectively), influences SR after 28days of a TWAA task. c-Fos expression, as a marker of neuronal activation, was also measured by immunohistochemistry 90min after the SR test in the amygdala and the medial prefrontal cortex. The temporal distribution of extinction sessions did not affect the degree of extinction learning. However, only the rats that underwent the 7-day spaced extinction paradigm maintained the level of extinction in the long term, showing no SR in TWAA. This behavioural finding was consistent with a greater number of c-Fos-labelled neurons in the infralimbic cortex in the 7-day group, and in the Lateral and Central nuclei of the amygdala in the 24-hour group. These findings show that a time-spaced extinction paradigm reduces the spontaneous recovery of active avoidance behaviour, and that this behavioural advantage appears to be related to the activation of the infralimbic cortex. Amygdala Infralimbic cortex Post-traumatic stress disorder (PTSD) Temporal distribution of extinction sessions Two-way active avoidance extinction C-fos Spaced sessions of avoidance extinction reduce spontaneous recovery and promote infralimbic cortex activation