[The relationship between free-running period and monoamines in the SCN].
Free-running period of blinded rats that had kept in a cage with a running wheel varied markedly between 23.4-24.7 h. The free-running period correlated negatively with motor activity (r = -0.61, P less than 0.005). In the SCN, 5-HT concentration correlated positively with motor activity (r = 0.70, P less than 0.005), consequently correlated negatively to the free-running period (r = -0.79, P less than 0.005). Similarly, 5-HIAA content showed weakly negative correlation to the free-running period (r = -0.45, P less than 0.05) but such correlation was never observed in other monoamines and their metabolites examined (NE, DA, DOPAC and HVA). Further, no correlation was seen between free-running period and contents of amines and their metabolites, including 5-HT and 5-HIAA, in the areas tested other than SCN. These facts suggest that motor activity affects the activity of serotonergic system in SCN, resulting in the change in the free-running period.
Shioiri
T
T
Department of Psychiatry, Shiga University of Medical Science, Otsu, Japan.
D000818:Animals; D002940:Circadian Rhythm; D004298:Dopamine / Q000378:metabolism; D006897:Hydroxyindoleacetic Acid / Q000378:metabolism*; D008297:Male; D009043:Motor Activity / Q000502:physiology*; D009638:Norepinephrine / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D012701:Serotonin / Q000378:metabolism* / Q000502:physiology; D013493:Suprachiasmatic Nucleus / Q000378:metabolism*
D012701:Serotonin; D006897:Hydroxyindoleacetic Acid; D004298:Dopamine; D009638:Norepinephrine