Somatostatin mRNA in the hippocampal formation following electroconvulsive shock in the rat

The effect of electroshock on the brain levels of somatostatin mRNA were evaluated by in situ hybridization using a selective oligonucleotide probe. Rats were submitted to single or repeated (7 days, one session for each day) sessions of electroshock. There was a marked increase of the expression of somatostatin mRNA in the hippocampal formation, mostly in the multiform layer of the hilus of the dentate gyrus, following repeated but not single electroshock. Our findings show that repeated ECS is associated with increase in the synthesis of somatostatin. The results also support previous data indicating that the hippocampal formation is selectively affected by the treatment.