Effects of dorsal raphe stimulation on cerebral glucose utilization in the anaesthetized rat

The aim of this study was to determine the effects of electrical stimulation of the dorsal raphe nucleus on local cerebral glucose utilization (LCGU) in the alpha-chloralose anaesthetized rat. Activation of the dorsal raphe nucleus effected significant increases in LCGU, ranging from 13 to 52% in 8 brain structures out of 33 investigated. Increases were restricted to extrapyramidal and limbic non-specific areas, and no modifications were observed in cortical areas. The comparison with our previous results, showing that a similar raphe activation induced a global decrease in local cerebral blood flow, suggests that the ascending serotonergic system may be of importance in the regulation of the cerebral circulation.