| Abstract: | Regional neural metabolic activity, as assessed by semiquantitative deoxyglucose (DG) autoradiography, was related to dehydration and ingestive behavior in 6-day-old rat pups. During simple ingestive responding, changes in relative DG uptake (representative of changes in neural metabolic activity) occurred primarily in hindbrain sensory and motor nuclei. Producing cellular dehydration resulted in activity changes primarily in the basal forebrain (FB). When Ss were dehydrated and allowed to ingest during the DG-uptake period, activity changes were seen in the hindbrain and FB areas that responded to ingestion or dehydration alone, as well as in regions that were not affected by either manipulation alone. Extracellular dehydration produced fewer and different FB responses in neural metabolic activity. During ingestion, the only effects of extracellular dehydration that overlapped with those of cellular dehydration appeared in circumventricular hypothalamic regions and brain stem motor nuclei. There appeared to be only a limited final common pathway for these 2 types of dehydration-induced drinking. Findings in infant rats depict distributed neural systems subserving ingestion and responding to state change and provide a starting point early in ontogeny for the developmental analysis of neural substrates of ingestive systems. (PsycINFO Database Record (c) 2010 APA, all rights reserved) |
