Neuronal localization of M2 muscarinic receptor immunoreactivity in the rat amygdala

▶There is a high density of neuropilar M2 immunoreactivity in the amygdala, especially in rostral portions of the basolateral amygdala. ▶A subset of M2+ nonpyramidal neurons that express GABA, somatostatin, and neuropeptide Y were observed in the lateral nucleus and adjacent external capsule. ▶Large spiny and large aspiny neurons associated with the intercalated nuclei were M2R+. ▶Many neuropeptide Y containing axons in the basolateral amygdala were M2R+. ▶Discrete subpopulations of M2R+ neurons were also seen in the central and medial nuclei.