Transitional states of the neuronal serotonergic site

Binding of [³H]5-HT was studied wuing purified neuronal membranes isolted frrom horse brain striatum. It is shown that the preincubation of these membranes with an agonist (5-HT, bufotenin) followed by washibng, modifined the binding of [³H]5-GT from a low affinity to a high affinity constant. This effect was blocked by previous pretreatment of the membranes with a sulfhydryl group reagent (N-ethylmaleimide) and was reversed by guanoside 5′-triphosphate.