Autoradiographic distribution of neuropeptide Y binding sites in the brain of the carp Cyprinus carpio L. (Cyprinidae, Teleostei).

The present study reports the distribution of neuropeptide Y (NPY)-binding sites in the brain of the adult carp Cyprinus carpio L. Radioiodinated NPY was used as tracer in the autoradiographic procedure. The NPY-binding sites (NPY-bs) were widely distributed in the carp brain. Generally, a good match was observed between the distribution of NPY-bs and the distribution of NPY-immunoreactive (NPY-ir) elements previously reported in the forebrain of the carp. Low to moderate concentration of NPY-bs were found in the telencephalon, this finding indicates that NPY may play a role in the processing of olfactory inputs and in more complex behaviours like spatial learning acquisition and retention, whose importance could correlated with similar results obtained in mammals. Moreover, in the rhombencephalon, the presence of NPY-bs at level of lobus vagus and the lobus facialis suggests that NPY may be implicated in food-seeking behaviour and swallowing reflex.