D-Glucose infusions into the basal ventromedial hypothalamus and feeding

Abstract

Following symmetrical bilateral infusion of d-glucose into the basal ventromedial hypothalamus (BVMH), using Alzet minipumps (1 μl/h of 10% d-glucose for 6 days), average daily food intake was reduced by 27% for the period of treatment. Symmetrical bilateral infusions into the posterior medial hypothalamus had a transitory effect on feeding, as did asymmetrical and unilateral infusions. Infusion of l-glucose into the BVMH did not yield a chronic reduction in food intake. Included in the infused solutions were tracer amounts of [ 14C]glucose, [ 14C]proline or [ 14C]leucine to permit radioautographic estimations of infusate dispersal in the brain and axonal transport patterns from the infusion sites. Infusions were generally well-restricted to 1–1.5 mm of the cannulae tips, and descending transport of amino acids was highest in substantia nigra and midline structures of the mesencephalon and pons including central gray, ventral tegmental area, raphe and ventral tegmental nuclei. These results provide evidence for an energy intake regulatory mechanism situated in the BVMH whose outputs may modulate activity in the substantia nigra and midline brain stem areas.