NEUROPEPTIDE-Y INJECTION INTO THE 4TH CEREBROVENTRICLE STIMULATES C-FOS EXPRESSION IN THE PARAVENTRICULAR NUCLEUS AND OTHER NUCLEI IN THE FOREBRAIN - EFFECT OF FOOD-CONSUMPTION

Injection of neuropeptide Y (NPY) into the cerebroventricular system o f the rat results in a robust feeding response. In this study, we obse rved that NPY injection into the fourth ventricle augmented feeding an d Fos-like immunoreactivity (FLI) in the paraventricular nucleus (PVN) and in other neighboring nuclei in the forebrain previously implicate d in stimulation of feeding. Since the rostral transport of NPY in cer ebrospinal fluid after injection into the fourth ventricle is unlikely and the topography of FLI as well as feeding behavior seen in this st udy are similar to those observed previously after NPY injection into the lateral cerebroventricle, these findings are in accord with the vi ew that feeding induced by NPY injection into the fourth ventricle may also be mediated by NPY receptive elements in the forebrain.