Early and prolonged widespread increase in brain protein synthesis following a single electroconvulsive shock in free-moving rats

The autoradiographic method with L-[S-35] methionine ([S-35]Met) was used t o determine the effect of a single electroconvulsive shock (ECS) on local r ates of protein synthesis in the adult rat brain in free-moving conditions. We have estimated the relative contribution of methionine derived from pro tein breakdown to the intracellular precursor amino acid pool (tRNA pool) f or protein synthesis. In steady-state conditions, we showed a large contrib ution (around 60%) of Met recycling into the precursor pool (lambda = 0.37 +/- 0.11), after a single ECS. In all the 36 brain regions examined, appare nt rates of protein synthesis were greatly increased (21-50%) 3 h after a s ingle ECS indicating a generalized effect in rat brain. This ECS-induced ac tivation of the overall rate of brain protein synthesis persisted for at le ast 24 h after cessation of ECS. This is consistent with the hypothesis tha t electroconvulsive therapy is associated with long-term molecular changes in neuronal activity. (C) 1999 Elsevier Science B.V. All rights reserved.