RAPID EYE-MOVEMENTS OF PARADOXICAL SLEEP - PHOTIC MODULATION OF CENTRAL MONO-AMINE ACTIVITY

The rapid eye movements (REMs) of paradoxical sleep evoke light-modulated potentials in the suprachiasmatic nucleus of the hypothalamus and in the ventral tegmental area of the mesencephalon, the junction of the cerebral monoamine pathways and origin of the mesolimbic dopamine system. Section of the lateral eye muscles abolishes only the REMs of paradoxical sleep without changing EEG or muscle atony of this state. Following lateral eye section in rats on a 12 h: 12 h light:dark cycle, the circadian rhythm of locomotor activation induced by low dose amphetamine-treatment is increased in amplitude and loses its normal relation to the light:dark cycle. These data support other evidence that the REMs of paradoxical sleep could serve as a regular source of photic information to parts of the brain which modulate biological rhythms in relation to daylight and darkness. Blinking may also be playing a related role. © 1979.