Threat imminence dictates the role of the bed nucleus of the stria terminalis in contextual fear.

Threat imminence dictates the role of the bed nucleus of the stria terminalis in contextual fear. Neurobiol Learn Mem. 2019 Nov 15;:107116 Authors: Goode TD, Acca GM, Maren S Abstract Recent work indicates that the bed nucleus of the stria terminalis (BNST) is critically involved in the regulation of conditioned fear responses to unpredictable threats. Here we examined whether the involvement of the BNST in contextual fear conditioning in male rats depends on the imminence of shock after placement in the conditioning chamber. Specifically, we hypothesized that the BNST supports contextual freezing after conditioning with delayed, but not imminent, footshock (relative to placement in the context). Rats were implanted with cannulae targeting the BNST and underwent a contextual fear conditioning procedure in which a single footshock unconditioned stimulus (US) was delivered either 1 minute or 9 minutes after the rat was placed in the context; the rats received a total of four identical conditioning sessions over two days, all with equivalent exposure to the context. Contexts associated with either imminent or delayed US onsets produced distinct patterns of freezing and shock-induced activity but freezing in each case was context-dependent. Reversible inactivation of the BNST reduced the expression of contextual freezing in the context paired with delayed (9 min), but not imminent (1 min), footshock onset. Implications of these data are ...
Source: Neurobiology of Learning and Memory - Category: Neurology Authors: Tags: Neurobiol Learn Mem Source Type: research