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. In the AN mice, without exception, the rhythms are free running. In the bi and mono animals they are either synchronized to the L/D cycle, or synchronized but phase shifted in comparison with C57 Black/6, or free running. For the mono and bi animals, the typical or atypical mode of synchronization of their rhythms to the L/D cycle appears to be correlated with the ganglion cell density. It is well known that such a retinal component ensures the retino-hypothalamic connections. In the C57 Black/6 and AN mice, differential pulse voltammetric measurements of 5-hydroxyindoleacetic acid (5-HIAA, peak 3) extracellular concentrations have been also realized together with polygraphic recordings of the sleep/waking cycle. In both strains, the height of the 5-HIAA peak 3 recorded in the cortex is always the highest during active waking, and decreases during slow wave sleep and paradoxical sleep. Further, a circadian variation of this signal is superimposed to that of the waking state amount. Such circadian variations are synchronized to the L/D cycle in C57 Black/6 animals and free running in the AN mice.
Faradji-Prevautel
H
H
Department of Experimental Medicine, University Claude-Bernard Lyon I, France.
Cespuglio
R
R
Jouvet
M
M
D000818:Animals; D000853:Anophthalmos / Q000503:physiopathology; D001143:Arousal / Q000502:physiology; D002452:Cell Count; D002940:Circadian Rhythm / Q000502:physiology*; D003010:Clorgyline / Q000494:pharmacology; D005124:Eye Abnormalities / Q000503:physiopathology*; D010134:Fenclonine / Q000494:pharmacology; D051379:Mice; D008810:Mice, Inbred C57BL; D008815:Mice, Inbred Strains; D010293:Pargyline / Q000494:pharmacology; D011903:Raphe Nuclei / Q000502:physiology*; D012160:Retina / Q000473:pathology / Q000502:physiology*; D012165:Retinal Ganglion Cells / Q000166:cytology / Q000473:pathology; D012701:Serotonin / Q000502:physiology*
D012701:Serotonin; D010293:Pargyline; D003010:Clorgyline; D010134:Fenclonine