Distribution of type I corticotropin-releasing factor (CRF1) receptors on GABAergic neurons within the basolateral amygdala.

The neuropeptide corticotropin-releasing factor (CRF) plays a critical role in mediating anxiety-like responses to stressors, and dysfunction of the CRF system has been linked to the etiology of several psychiatric disorders. Extra-hypothalamic CRF can also modulate learning and memory formation, including amygdala-dependent learning. The basolateral nucleus of the amygdala (BLA) contains dense concentrations of CRF receptors, yet the distribution of these receptors on specific neuronal subtypes within the BLA has not been characterized. Here, we quantified the expression of CRF receptors on three nonoverlapping classes of GABAergic interneurons: those containing the calcium-binding protein parvalbumin (PV), and those expressing the neuropeptides somatostatin (SOM) or cholecystokinin (CCK). While the majority of PV+ neurons and roughly half of CCK+ neurons expressed CRF receptors, they were expressed to a much lesser extent on SOM+ interneurons. Knowledge of the distribution of CRF receptors within the BLA can provide insight into how manipulations of the CRF system modulate fear and anxiety-like behaviors.