Memory processing and apamin induce immediate early gene expression in mouse brain.
The present study analyses the effects of learning on the spatial pattern and the time-course of changes of immediate early gene messenger RNA's (c-fos and c-jun) in mouse brain produced by training in an appetitive bar-pressing task. Activation of c-fos and c-jun after training is strictly located in the hippocampal formation and is learning-dependent. Levels of both proto-oncogene mRNAs in the trained group were 4 to 5 times higher than in the sham-conditioned group. Injections of apamin, a bee venom neurotoxin that selectively blocks a class of Ca(2+)-activated K+ channels and improves learning and memory retention, produced as compared to untrained animals a 3- to 5-fold increase of expression of c-fos and c-jun with the same pattern as that observed in the trained animals. Post-training injection of 0.2 mg/kg apamin enhanced 1.4-fold the expression of both immediate early genes in CA1, CA3 and dentate gyrus as compared to trained saline-injected mice. All these results suggest that apamin-induced increase of immediate early gene expression might be related to the apamin-induced facilitation of learning.
Heurteaux
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C
Institut de Pharmacologie Moléculaire et Cellulaire, UPR 411 du CNRS, Sophia Antipolis, Valbonne, France.
Messier
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Destrade
C
C
Lazdunski
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M
D000818:Animals; D001030:Apamin / Q000494:pharmacology*; D002118:Calcium / Q000378:metabolism; D005786:Gene Expression Regulation / Q000187:drug effects; D016762:Genes, fos; D016758:Genes, jun; D006624:Hippocampus / Q000187:drug effects / Q000378:metabolism*; D007858:Learning / Q000502:physiology; D008297:Male; D008568:Memory / Q000502:physiology*; D051379:Mice; D008807:Mice, Inbred BALB C; D015221:Potassium Channels / Q000187:drug effects*; D013268:Stimulation, Chemical
D015221:Potassium Channels; D001030:Apamin; D002118:Calcium