Corticosterone modulation of neurotransmitter receptors in rat hippocampus: a quantitative autoradiographic study

The effect of adrenalectomy (ADX) and corticosterone (CORT) replacement on neurotransmitter receptors was studied in dorsal hippocampus of rat using quantitative autoradiography. ADX for one week causes an increase in [3H]5-HT binding to 5-HT1 receptors which is significant in the CA1 cell field. CORT treatment of ADX rats for 3-5 days results in localized reductions of [3H]5-HT binding including a partial reversal of the increase observed after ADX in CA1. CORT treatment of ADX animals also decreases binding of [3H]QNB to muscarinic receptors in the dorsal hippocampus, with a significant effect in an area designated as subiculum. No influence of CORT was detected on [3H]prazosin binding to alpha 1 adrenergic receptors in dorsal hippocampus. Possible mechanisms for hormone effects on neurotransmitter receptor levels are discussed.