Figure 3. 5-HT_1A expression displayed extensive overlapping expression with neuropeptides cholecystokinin-8 (CCK8), neuropeptide Y (NPY) and the neuropeptide Y-1 receptor (NPY_1R).

Immunocytochemical double labeling examples are presented for 5-HT_1A and CCK8 in fungiform (FP) and foliate (FOL) papillae, for 5-HT_1A and NPY in fungiform and foliate papillae, and for 5-HT_1A and NPY-1R in foliate papillae. Since these neuropeptides are known to be expressed in type II cells, these co-expression patterns corroborate expression of 5-HT_1A in type II cells. Scale bars are 15 microns.