Vagus Nerve Stimulation Enhances Extinction of Conditioned Fear in Rats and Modulates Arc Protein, CaMKII, and GluN2B-Containing NMDA Receptors in the Basolateral Amygdala

Figure 3

VNS accelerates molecular mechanisms of extinction learning. (a) Timeline of behavioral protocol. On days 1 and 2 rats were subjected to auditory fear conditioning (AFC). One cohort was sacrificed 45 min after AFC. Another cohort underwent a conditioned fear response test (CFRT; day 3), followed by extinction training (EXT) or extended-extinction (EE) training (day 4), and was sacrificed 45 min later. (b-c) Rats given VNS during extinction training show higher levels of p-CaMKII and GluN2B compared to rats given sham during extinction training and rats that underwent auditory fear conditioning alone (FC; ) and do not differ from rats that underwent extended extinction. (d) Rats given VNS during extinction training show lower levels of Arc protein compared to all other groups ().

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