Electroconvulsive therapy is an effective and rapid treatment for depression. In patients with depression, the function of the paraventricular nucleus of the hypothalamus (PVN) is frequently altered. Electroconvulsive seizure (ECS), which is a model of electroconvulsive therapy, upregulates the expression of c-fos in the PVN of animal models. Therefore, we hypothesized that ECS alters gene expression and function in the PVN. The PVN was microdissected from mouse brain sections following ECS treatment, and total RNA was analyzed by microarray. Two hours after ECS, the levels of expression of 2.6% (589 genes) of the genes showed a greater than 2-fold decrease and 0.9% (205 genes) showed a greater than 2-fold increase. Among these genes, 72 of the downregulated genes and 12 of the upregulated genes have been proposed to be associated with psychiatric disorders, such as depression, by knowledge database analyses. The groups of downregulated genes included neuropeptides (Cck), kinases (Prkcb, Camk2a), transcription factors (Tcf4), and transporters (Aqp4), and these have been suggested to be associated with psychiatric disorders and/or PVN function. The results of the present study indicated that ECS treatment could modulate PVN functions through altered gene expression, which may contribute to its antidepressant effects.

The ventromedial nucleus of the hypothalamus (VMH) plays an important role in feeding and energy homeostasis. Electroconvulsive seizure (ECS) therapy is highly effective in the treatment of several psychiatric diseases, including depression, but may also have beneficial effects in other neurological diseases. Although it has been reported that the neurons of the VMH are strongly activated by ECS stimulation, the specific effects of ECS in this hypothalamic subnucleus remain unknown. To address this issue, we investigated the changes in gene expression in microdissected-VMH samples in response to ECS in mice, and examined the behavioral effects of ECS on feeding behavior. ECS significantly induced the expression of immediate-early genes such as Fos, Fosb, and Jun, as well as Bdnf, Adcyap1, Hrh1, and Crhr2 in the VMH. Given that signals of these gene products are suggested to have anorexigenic roles in the VMH, we also examined the effect of ECS on food intake and body weight. Repeated ECS had a suppressive effect on food intake and body weight gain under both regular and high-fat diet conditions. Furthermore, gold-thioglucose-induced hypothalamic lesions, including the VMH and the arcuate nucleus, abolished the anorexigenic effects of ECS, indicating the requirement for the activation of the hypothalamus. Our data show an effect of ECS on increased expression of anorexigenic factors in the VMH, and suggest a role in the regulation of energy homeostasis by ECS.

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