Galanin (GAL) and Neuropeptide Y (NPY) are neuropeptides involved in
behaviors associated with anxiety. Both neuropeptides interact in several
central functions. However, the potential behavioral and cellular interactions
between them in anxiety are unknown. GAL was found to act through GAL
receptor 2 (GALR2) to enhance NPYY1 receptor (NPYY1R) mediated anxiolytic
behaviors in rats. Using receptor autoradiography, c-fos expression and in situ
proximity ligation assay, the medial paracapsular intercalated nuclei of the
amygdala were determined to be a key area in the interaction probably
involving the formation of GALR2/NPYY1R heteroreceptor complexes. In cell
cultures co-stimulation of GALR2 and NPYY1R induced changes in the
functions of these receptors. The changes involved a potentiation of the
decrease in the phosphorylation of CREB induced by NPYY1R and a delay in
the internalization of NPYY1R. These results indicate that GALR2/NPYY1R
interactions can provide a novel integrative amygdaloid mechanism in anxiety.
