INTRODUCTION: The central nucleus of the amygdala (CeA) has primarily been studied as a structure involved in processing of aversive behaviors, whereas its role in appetitively-motivated learning is less understood. The published data show involvement of the basolateral amygdala (BL), which sends projections to the CeA, in encoding sensory‑specific features during appetitive learning. In contrast, the CeA was implicated in modulation of incentive motivation to pursue an associated external reward. Previously we reported that after appetitive, but not aversive learning, expression of c-Fos, a protein closely linked to synaptic plasticity, is significantly increased in the CeA. AIM(S): We aimed at testing the hypothesis that appetitive learning depends on c-Fos expressing neural circuits in the CeA. METHOD(S): We first compared c‑Fos expression pattern in the amygdala following place preference and place avoidance training and examined inputs from the BL on the activated CeA neurons. Then we used c-fos-driven targeting of channelrhodopsin and trained the animals in an operant conditioning task, in which they learned to associate auditory stimulus with food reinforcement. To further test the role of c-fos-expressing neurons in appetitive learning, we locally blocked behaviorally-induced c-fos expression using a shRNA. RESULTS: The c‑Fos expression in the CeA wassignificantly higher following place preference than place avoidance training, with over 90% of the c‑Fos positive cells receiving projections from the BL. Optogenetic stimulation of the neurons increased bar-pressing responses but only when the conditioned stimulus was present. Blocking c-fos expression resulted in impairment of appetitively but not aversively motivated discrimination learning and decreased motivation to seek reward. CONCLUSIONS: The results reveal that c-fos expression in the CeA neurons is necessary for appetitively but not aversively motivated learning, modulating of incentive motivation but not reward consumption. FINANCIAL SUPPORT: Tomasz Lebitko was supported by NCN grant Sonata UMO-2012/05/D/NZ3/02085 to Tomasz Jaworski.
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.