A. Akabayashi et al., GALANIN-CONTAINING NEURONS IN THE PARAVENTRICULAR NUCLEUS - A NEUROCHEMICAL MARKER FOR FAT INGESTION AND BODY-WEIGHT GAIN, Proceedings of the National Academy of Sciences of the United Statesof America, 91(22), 1994, pp. 10375-10379
The physiological function of the peptide galanin (Gal) remains to be
established. It is known to exist in high concentrations within the hy
pothalamus and to modulate the secretion of specific hormones, as well
as to potentiate food consumption. Our study provides evidence for an
essential function of neuronal Gal, within a specific hypothalamic ar
ea, in stimulating the behavioral process of fat ingestion and body we
ight gain. Through analyses of peptide levels via RIA and of gene expr
ession via in situ hybridization, a close positive association is esta
blished between Gal in the paraventricular nucleus (PVN), particularly
its midlateral region, and fat ingestion. No such relationship is det
ected for Gal in other brain areas or between PVN Gal and ingestion of
carbohydrate or protein, supporting the behavioral and anatomical spe
cificity of this relationship. Through PVN injection studies with anti
sense oligonucleotides to Gal mRNA, a dramatic decline in fat ingestio
n and body weight suggests that endogenous Gal contributes to the natu
ral appetite for fat. Thus, Gal in the PVN is identified as a neuroche
mical marker for fat ingestion and, consequently, body weight gain.