TY - JOUR T1 - Disruption of Arcuate/Paraventricular Nucleus Connections Changes Body Energy Balance and Response to Acute Stress JF - The Journal of Neuroscience JO - J. Neurosci. SP - 6707 LP - 6713 DO - 10.1523/JNEUROSCI.20-17-06707.2000 VL - 20 IS - 17 AU - M. Elizabeth Bell AU - Seema Bhatnagar AU - Susan F. Akana AU - SuJean Choi AU - Mary F. Dallman Y1 - 2000/09/01 UR - http://www.jneurosci.org/content/20/17/6707.abstract N2 - The mediobasal hypothalamus regulates functions necessary for survival, including body energy balance and adaptation to stress. The purpose of this experiment was to determine the contribution of the arcuate nucleus (ARC) in controlling these two functions by the paraventricular nucleus (PVN). Circular, horizontal cuts (1.0 mm radius) were placed immediately above the anterior ARC to sever afferents to the PVN. In shams the knife was lowered to the same coordinates but was not rotated. Food intake and body weight were monitored twice daily, at the beginning and end of the light cycle, for 1 week. On the final day the animals were restrained for 30 min. Lesioned animals had increased food intake in light and dark periods, higher weight gain per day, and more body fat as compared with shams. There was no difference in caloric efficiency. Unlike shams, lesioned rats had no predictable relationship between plasma insulin and leptin. Plasma ACTH was increased at 0 min in lesioned rats but was decreased 15 and 30 min after restraint as compared with shams. There was no difference in plasma corticosterone. Immunostaining revealed that α-melanocortin (αMSH) and neuropeptide Y (NPY) accumulated below the cuts, and both were decreased in PVN. Food intake and body weight were correlated negatively to αMSH, but not NPY in PVN. There was no difference in proopiomelanocortin (POMC) mRNA, but NPY mRNA was reduced in the ARC of lesioned animals. We conclude that ARC controls body energy balance in unstressed rats, possibly by αMSH input to PVN, and that ARC also is necessary for PVN regulation of ACTH. ER -