Electroconvulsive shock produces large increases in interstitial concentrations of dopamine in the rat striatum: an in vivo microdialysis study.

This study examined the effects of electroconvulsive shock (ECS) on interstitial concentrations of dopamine (DA) and its metabolites, 3,4-dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA), the serotonin metabolite 5-hydroxyindoleacetic acid (5-HIAA), and the purine metabolite uric acid, in the striatum using on-line microdialysis in freely moving rats. Interstitial striatal DA increased to 1310% of baseline when the ECS was administered 18 to 24 hours after implantation of the dialysis probe. DOPAC (+ 19%), HVA (+ 30%), 5-HIAA (+10%), and uric acid (+111%) were increased to a smaller extent. The ECS-induced increase in DA was derived from a Ca++ sensitive pool since perfusion of a modified solution in which Ca++ had been replaced with Mg++ blocked this effect.