DIETARY PREFERENCES IN MONOSODIUM GLUTAMATE-LESIONED RATS - AGE-VARIABLE INFLUENCE OF HYPOTHALAMIC NEUROPEPTIDE-Y

In this study, we measured hypothalamic neuropeptide Y (NPY) and the f ood preferences in weanling and adult monosodium glutamate (MSG)-lesio ned and control rats. The MSG lesion was induced by three subcutaneous injections (4 g/kg body wt) during the first week of life of the rats . All treated and control weanling rats strongly preferred a high carb ohydrate (HC) diet to a high fat (HC) diet. Adult control rats ate 60% more HF diet (P < 0.001) and 25% less HC diet (P < 0.01) than MSG-tre ated rats. At weaning and in adulthood, NPY concentrations in MSG-rats were markedly lower in the arcuate and paraventricular nuclei (P < 0. 01 or less) than in control rats. The MSG treatment did not affect car bohydrate preference observed at weaning. It was associated with a lim ited development of fat appetite in adulthood. NPY could influence the dietary preferences more in adulthood, likely when all neuropeptiderg ic systems are mature. (C) 1997 Elsevier Science Ireland Ltd.