Quantified Coexpression Analysis of Central Amygdala Subpopulations.

Molecular identification and characterization of fear controlling circuitries is a promising path towards developing targeted treatments of fear-related disorders. Three-color in situ hybridization analysis was used to determine whether somatostatin (SOM, Sst ), neurotensin (NTS, Nts ), corticotropin-releasing factor (CRF, Crf ), tachykinin 2 (TAC2, Tac2 ), protein kinase c-δ (PKC-δ, Prkcd ), and dopamine receptor 2 (DRD2, Drd2 ) mRNA colocalize in male mouse amygdala neurons. Expression and colocalization was examined across capsular (CeC), lateral (CeL), and medial (CeM) compartments of the central amygdala. The greatest expression of Prkcd and Drd2 were found in CeC and CeL. Crf was expressed primarily in CeL, while Sst -, Nts -, and Tac2 -expressing neurons were distributed between CeL and CeM. High levels of colocalization were identified between Sst , Nts , Crf , and Tac2 within the CeL, while little colocalization was detected between any mRNAs within the CeM. These findings provide a more detailed understanding of the molecular mechanisms that regulate the development and maintenance of fear and anxiety behaviors.