This Article Full Text Full Text (PDF) All Versions of this Article: 147/4/1744    most recent Author Manuscript (PDF) Purchase Article View Shopping Cart Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Copyright Permission Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Kuramochi, M. Articles by Yada, T. Search for Related Content PubMed PubMed Citation Articles by Kuramochi, M. Articles by Yada, T.

Galanin-Like Peptide Stimulates Food Intake via Activation of Neuropeptide Y Neurons in the Hypothalamic Dorsomedial Nucleus of the Rat

Department of Physiology, Division of Integrative Physiology (M.K., T.O., D.K., T.Y.), and Department of Neuropsychiatry (M.K., S.K.), Jichi Medical School, Minamikawachi, Tochigi 329-0498, Japan

Address all correspondence and requests for reprints to: Dr. Toshihiko Yada, Department of Physiology, Division of Integrative Physiology, Jichi Medical School, Minamikawachi, Kawachi, Tochigi 329-0498, Japan. E-mail: tyada{at}jichi.ac.jp.

Galanin-like peptide (GALP), a 29-amino-acid neuropeptide, is located in the hypothalamic arcuate nucleus (ARC), binds to galanin receptor subtype 2, and induces food intake upon intracerebroventricular (icv) injection in rats. However, neural mechanisms underlying its orexigenic action remain unclear. We aimed to identify the nuclei and neuron species that mediate the food intake in response to icv GALP injection. Intracerebroventricular injection of GALP, as powerfully as that of neuropeptide Y (NYP), increased food intake for the initial 2 h. GALP injected focally into the dorsomedial nucleus (DMN), but not the ARC, lateral hypothalamus, or paraventricular nucleus (PVN), stimulated food intake for 2 h after injection. In contrast, galanin injected into the DMN had no effect. DMN-lesion rats that received icv GALP injection showed attenuated feeding compared with control rats. Intracerebroventricular GALP injection increased c-Fos expression in NPY-containing neurons in the DMN, but not the ARC. GALP increased the cytosolic calcium concentration ([Ca²⁺]_i) in NPY-immunoreactive neurons isolated from the DMN, but not the ARC. Furthermore, both anti-NPY IgG and NPY antagonists, when preinjected, counteracted the feeding induced by GALP injection. These data show that icv GALP injection induces a potent short-term stimulation of food intake mainly via activation of NPY-containing neurons in the DMN.

This article has been cited by other articles:

				D. Kohno, M. Nakata, F. Maekawa, K. Fujiwara, Y. Maejima, M. Kuramochi, T. Shimazaki, H. Okano, T. Onaka, and T. Yada Leptin Suppresses Ghrelin-Induced Activation of Neuropeptide Y Neurons in the Arcuate Nucleus via Phosphatidylinositol 3-Kinase- and Phosphodiesterase 3-Mediated Pathway Endocrinology, May 1, 2007; 148(5): 2251 - 2263. [Abstract] [Full Text] [PDF]