Parallel Development and Maturation of GABAergic Interneurons and Corticotrophin-releasing Factor Signaling within the Amygdala Complex.

The amygdala complex is known to play a critical role in supporting adaptive behaviors in response to environmental stimuli, particularly during sensitive periods of brain development. Through its connections, the amygdala modulates hippocampal and striatal-dependent memories and shapes distinct cortical function within the emotional and cognitive domains. Major neural circuit remodeling is known to occur in the amygdala during postnatal development through adolescence, which includes the maturation of its excitatory connectivity and the progressive organization of local GABAergic inhibitory interneurons. Thus, the goal of this paper is to review current knowledge on how developmental trajectories of distinct GABAergic interneuron populations within the amygdala are temporally staggered to enable successive sensitive periods during which environmental input impacts amygdala-dependent emotional learning, threat processing, and social behavior. This review will discuss the early emerging somatostatin and neuropeptide Y interneurons, later maturing parvalbumin-positive interneurons, and developmental changes in stress-responsive corticotrophin-releasing factor signaling. We examine how these trajectories may shape age-appropriate behavior and sensitivity to early life adversity as GABAergic circuits within the amygdala mature.