Noradrenergic subsensitivity and supersensitivity of the cerebral cortex after reserpine treatment.

Changes in the sensitivity of the cyclic adenosine 3', 5'-monophosphate response of rat brain cerebral cortical slices to norepinephrine were measured in vitro after the rats received i.p. injections of reserpine (1 mg/kg). Subsensitivity was evident 1 hour after a single reserpine treatment compared with saline controls. However, if reserpine was injected daily for 4 days followed by 1 day without reserpine treatment, a supersensitive response to NE was shown compared to the controls. Mean pD2 values are presented to illustrate the shifts of the dose-response curves after reserpine treatment. The present work demonstrated the induction of noradrenergic sub- and supersensitivity to norepinephrine in rat cerebral cortical slices after acute and 4-day reserpine treatment, respectively.