Effect of electroconvulsive shock on the uptake and release of noradrenaline and 5-hydroxytryptamine in rat brain slices.

The uptake and release of [3H]noradrenaline and [3H]-5-hydroxytryptamine (5-HT) were studied in cerebral cortex slices from rats 30 min and 24 h after a single electroconvulsive shock (ECS) and 24 h after a series of five shocks given over 10 days. Both the Km and Vmax for 5-HT uptake were lower than controls 24 h after a single ECS, whereas after 5 ECS spread over 10 days both parameters remained depressed, though only the fall in Vmax was significant. Noradrenaline uptake was not altered after a single ECS, but the Vmax and Km were elevated following chronic ECS treatment. Neither ECS treatment schedule had any effect on the potassium-stimulated release of either transmitter. It is possible that the changes in monoamine uptake seen following ECS are an adaptive response to alterations in the synaptic cleft concentration of these transmitters.