BETA-ADRENERGIC RECEPTORS MEDIATE A STRESS-INDUCED DECREASE IN IGF-IIMESSENGER-RNA IN THE RAT CEREBELLUM

1. Exposure to a combined forced swimming-confinement stress resulted in a decrease in insulin-like growth factor II (IGF-II) mRNA levels in the whole brain (without the cerebellum) and in the isolated brain ar eas of the cerebral cortex, the hippocampus, and the cerebellum. 2. In an effort to elucidate the neurotransmitter systems involved in this stress-induced decrease, animals were injected prior to exposure to th e stress, with either propranolol, diazepam, or MK-801. 3. Administrat ion of diazepam or MK-801 did not affect the stress-induced decrease i n IGF-II mRNA in any of the three brain areas examined. 4. Administrat ion of propranolol prior to the exposure to the stress inhibited the s tress-induced decrease in IGF-II mRNA in the cerebellum. Propranolol h ad no such effect in the cerebral cortex or the hippocampus. 5. Our re sults suggest that in the cerebellum, the stress-induced decrease in I GF-II mRNA is mediated by beta(2)-adrenergic receptors.