Effects of idebenone, a cerebral metabolism activator, on muricidal behavior in rats with raphe lesions.

The effects of idebenone, a cerebral metabolism activator, on mouse-killing behavior (muricide) in rats with lesions of the midbrain raphe nuclei were studied. Single administration of idebenone (30 and 100 mg/kg, IP) inhibited the muricidal behavior in the raphe-lesioned rats in a dose-dependent manner. Idebenone also suppressed muricide in the olfactory bulbectomized rats, although the effect was less marked than that shown in the raphe-lesioned rats. In addition, the antimuricidal effect of idebenone was augmented with repeated administration. These results support previous findings that idebenone has an activating action on central serotonergic neurons in rats and in patients with cerebrovascular dementia, and suggest that idebenone may improve some of the depressive symptoms often observed in patients with cerebrovascular lesions and other forms of brain disturbance.