title: Diurnal changes in the rabbit's visual evoked potential.
abstract: Rabbits that have been exposed to the natural cycles of day and night exhibit marked diurnal changes in the shape of their Visual Evoked Potential in constant environmental conditions. The results of exposure to artificial 24 hr light-dark cycles strongly suggest that it is the regular alternation of daylight and darkness which acts as the synchronizing "Zeitgeber" for the V.E.P. rhythm which exists after exposure to the natural cycles of day and night. It would seem further that the V.E.P. changes reflect a square-wave like rhythm in the sensitivity of the visual system to photic stimuli, in which the sensitivity is much higher at night than in the day-time. The probable importance of the diurnal V.E.P. rhythm for the occurrence of daily fluctuations in behaviour is discussed.
mesh_terms: D000818:Animals; D002940:Circadian Rhythm; D004569:Electroencephalography; D005071:Evoked Potentials; D005260:Female; D008297:Male; D010775:Photic Stimulation; D011817:Rabbits / Q000502:physiology*; D013997:Time Factors; D014785:Vision, Ocular / Q000502:physiology*