CYCLIC NUCLEOTIDES IN MURINE BRAIN - TEMPORAL RELATIONSHIP OF CHANGES INDUCED IN ADENOSINE-3',5'-MONOPHOSPHATE AND GUANOSINE 3',5'-MONOPHOSPHATE FOLLOWING MAXIMAL ELECTROSHOCK OR DECAPITATION

c(Cyclic)AMP levels increased about 5-fold in the cerebral cortex and 2-fold in the cerebellum following electroconvulsive shock (ECS). The peak levels of cAMP occurred at 45 s after ECS in the cerebral cortex and at 15 s in the cerebellum. In the cerebral cortex ECS produced twice the cAMP accumulation as did decapitation in a comparable time period; the relative effect of a number of neurotropic agents on the cAMP accumulation was essentially the same, whether stimulated by decapitation or by ECS. In the cerebellum the levels of cGMP also increased following ECS. The cGMP levels were greatest at 60 s after ECS during the postictal depression. An association between elevated cerebellar cGMP and depression seemed unlikely, since CNS depressants either lowered or had no effect on cGMP levels. Cyclic nucleotide profiles following treatments such as ECS or decapitation may be useful in elucidating the molecular events involved in seizures, brain injury and ischemia.