To evaluate the influences of adrenocortical hormone on the signal transduction system in young brain, the authors observed the effects of bilateral adrenalectomy on the induction of immediate early genes(IEGs) such as c-fos, jun B, and TIS I by
electroconvulsive shock(ECS) in the young rats.
The young(70g) male Sprague-Dawley rats were treated with ECS(130V, 0.5sec) at day 3 or 14 after bilateral adrenalectomy. They were sacrificed at 0, 15, 30, 45, and 60 minutes after ECS, and cerebral cortex and hippocampus were dissected from
their
brains. The induction of IEGs were assessed with northern hybridization. The band intensities of the autoradiographs measured by densitometer were compared by between adrenalectomized group and shamoperated control group.
In the cerebral cortex, c-fos and jun B appeared and disappeared carlier, and enhanced in the earlier phase of the induction in the adrenalectomized group. These trends were more prominent for jun B than for c-fos, and were more prominent at day
14
than
at day 3 after adrenalectomy. The induction of TIS I was attenuated at day 14 after adrenalectomy. In the hippocampus, the induction of c-fos and jun B by ECS was not influenced by adrenalectomy. The induction of TIS I was attenuated at day 3
after
adrenalectomy.
These results suggest that adrenalectomy has influences on the induction of IEGs by ECS in rat brain differently, depending on the brain region, the kind of IEGs, the age of rats, and the time passed after adrenalectomy.
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