Motivation, Emotion, Feeding, DrinkigIncreased response to NPY of hypothalamic VMN neurons in postnatally overfed juvenile ratsHeidel, Einar1,3; Plagemann, Andreas2; Davidowa, Helga1Author Information 1Institute of Physiology, Faculty of Medicine (Charité), Humboldt University Berlin, Tucholskystr. 2, D-10117 Berlin, Germany 2Institute of Experimental Endocrinology, Faculty of Medicine (Charité), Humboldt University Berlin, Tucholskystr. 2, D-10117 Berlin, Germany. 3Corresponding Author: Einar Heidel ACKNOWLEDGEMENTS: This work was supported by the German Ministry for Research and Technology (Grant 01 ZZ 9511). Received 17 March 1999; accepted 18 April 1999 NeuroReport: June 23rd, 1999 - Volume 10 - Issue 9 - p 1827-1831 Buy Abstract RATS postnatally overnourished due to a reduced litter size become persistently overweight. A presumed pathophysiological mechanism consists of a change in the activity and responsiveness to neuropeptides of the neuronal system regulating feeding behavior. This study aimed to find differences in the action of neuropeptide Y, orexin-A and cholecystokinin on single unit activity of the ventromedial hypothalamic nucleus in brain slices of normal and postnatally overfed juvenile rats. NPY inhibited significantly more neurons (15 of 23) of obese than of normal rats (6 of 27; p <0.01, χ2). Orexin-A and CCK-8S mainly activated the neurons without significant differences between the groups. In conclusion, the stronger inhibition by NPY of VMN neurons which signal satiety might contribute to increased feeding behavior in postnatally overfed rats. © 1999 Lippincott Williams & Wilkins, Inc.