A Central Amygdala-Substantia Innominata Neural Circuitry Encodes Aversive Reinforcement Signals

Abstract

Summary: Aversive stimuli can impact motivation and support associative learning as reinforcers. However, the neural circuitry underlying the processing of aversive reinforcers has not been elucidated. Here, we report that a subpopulation of central amygdala (CeA) GABAergic neurons expressing protein kinase C-delta (PKC-δ+) displays robust responses to aversive stimuli during negative reinforcement learning. Importantly, projections from PKC-δ+ neurons of the CeA to the substantia innominata (SI) could bi-directionally modulate negative reinforcement learning. Moreover, consistent with the idea that SI-projecting PKC-δ+ neurons of the CeA encode aversive information, optogenetic activation of this pathway produces conditioned place aversion, a behavior prevented by simultaneous ablating of SI glutamatergic neurons. Taken together, our data define a cell-type-specific neural circuitry modulating associative learning by encoding aversive reinforcement signals. : Cui et al. show that central amygdala PKC-δ+ neurons can modulate negative reinforcement learning by transmitting aversive signals to the substantia innominata. Keywords: central amygdala, negative reinforcement learning, substantia innominate, aversive signals