Valence-dependent contribution by the basolateral amygdala to active but not inhibitory avoidance and reward-seeking

Abstract

The basolateral amygdala (BLA) is integral for promoting instrumental actions to avoid aversive events, and also contributes to certain aspects of reward-seeking. However, this sometimes requires discriminating between stimuli to ascertain whether it is more appropriate to initiate or suppress actions to obtain these goals. The present study examined BLA involvement in different avoidance strategies in male and female rats well-trained on different lever-press avoidance and reward-seeking tasks. Active/inhibitory avoidance required discrimination between tones presented pseudorandomly in a session that signaled shocks could be avoided by making or withholding a press on a lever inserted coincidentally with tone presentation. BLA inactivation (via infusion of GABA agonists) reduced active avoidance while slightly enhancing inhibitory avoidance in the same session. Similarly, on a dual-cued appetitive go/no-go task, BLA inactivation also impaired active, but not inhibitory reward-seeking. These treatments also disrupted performance in rats trained on a simpler, single-cue active avoidance task with no inhibitory component. However, rats trained on a single-cue reward task were impervious to the effects of BLA inactivation. Few sex differences were observed. These data reveal a fundamental contribution by the BLA in promoting actions to avoid punishments or secure rewards when an actor must discriminate between different stimuli to ascertain whether actions should be made or withheld, and may attenuate inhibitory avoidance when active strategies are sometimes required. Yet, under more rudimentary conditions where a single stimulus provokes actions, the valence of the pursued goal biases BLA involvement, as it remains critical for instrumental avoidance, but not reward-seeking.