Acute and long lasting neurochemical effects of monosodium glutamate administration to mice.

Acute administration of excitatory amino acids alters the release of anterior pituitary hormones. The neurochemical effects of monosodium glutamate (MSG) administration to adult mice were examined 30 minutes and 60 days after an acute injection (4 mg/g). The permanent effects of an acute injection of MSG were limited to a slight loss of neurons in the ventral arcuate nucleus and a 21% reduction in hypothalamic 5-HIAA levels. Thirty minutes after MSG administration hypothalamic DA and DOPAC levels were increased 27% and 25%, respectively and MOPEG levels were increased 75% in the hypothalamus and 34% in the remaining whole brain. These findings show that the acute administration of MSG results in alterations in hypothalamic monoamine metabolism which may be related to the neuroendocrine consequences of excitatory amino acid administration.