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Effect of Forced‐Running Stress on β‐Adrenergic Receptors in Rat Brain Regions and Liver
Author(s) -
Nakamura Toyonori
Publication year - 1992
Publication title -
psychiatry and clinical neurosciences
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.609
H-Index - 74
eISSN - 1440-1819
pISSN - 1323-1316
DOI - 10.1111/j.1440-1819.1992.tb00833.x
Subject(s) - hippocampus , endocrinology , medicine , pons , receptor , midbrain , hypothalamus , cerebellum , behavioural despair test , cerebral cortex , agonist , chemistry , central nervous system , antidepressant
Rats were exposed to forced‐running stress for 1 day, 3 days or a long term (approximately 2 weeks), and P‐adrenergic receptor binding was then assayed using [ 3 H]dihydroalprenoloI (DHA) in six brain regions and the liver. In the pons + med.obl., hypothalamus and midbrain, a reduction in Fadrenergic receptor density was first evident on day 1. In contrast, a decrease in Fadrenergic receptor density in the cerebral cortex and hippocampus was first evident on day 3. Decreased [ 3 H]DHA binding in the pons + med.obl., cerebral cortex and hippocampus subsequently plateaued for the duration of the forced‐running stress. In the midbrain and hypothalamus, however, decreased [ 3 H]DHA binding subsequently returned to control levels despite the exposure to the forced‐running stress. In the cerebellum and the liver, [ 3 H]DHA binding did not change significantly throughout the stress. These results indicate that the forced‐running stress induces both the time‐ and region‐specific changes in Fadrenergic receptors. Moreover, the rats showed either a behavioral depression or a spontaneous recovery of running activity during the 2 weeks following the end of the long‐term stress. Thus, we also examined the relationship of P‐adrenergic receptors to these behavioral differences. [ 3 H]DHA binding for the behavioral depression group was lower in the hippocampus and higher in the liver than for the spontaneous recovery group.