5-Hydroxyindoles compounds and nitric oxide voltammetric detection in the rat brain: changes occurring throughout the sleep-wake cycle.

The release of serotonin may occur throughout the sleep-wake cycle according to 2 different modalities: - by the axonal nerve endings during waking; - by the dendrites and/or the soma of the nucleus raphe dorsalis (nRD) during sleep. Neuronal nitric oxide (NO), synthesised by constitutive NO synthase (NOS), is colocalized with neurotransmitters such as GABA, acetylcholine, somatostatin, serotonin, etc. In order to evaluate its modalities of release throughout the rat sleep-wake cycle, a sensor allowing its specific detection in freely moving animals was prepared.

Circadian rest-activity rhythms in the anophthalmic, monocular and binocular ZRDCT/An mice. Retinal and serotoninergic (raphe) influences.

In the present study, two strains of mice were used: the control C57 Black/6 and the experimental ZRDCT/An, composed of anophthalmic (AN), monocular (mono) and binocular (bi) animals. The circadian rest-activity rhythms of these mice, submitted to a 12 h/12 h light/dark (L/D) cycle, present different characteristics. In C57 Black/6 animals the rhythms are classically synchronized to the L/D cycle with a maximal activity during the dark period, mainly at its beginning.