Circadian rhythm of optic nerve impulses recorded in darkness from isolated eye of Aplysia.
The isolated eye of the sea hare Aplysia califomica shows a circadian rhythm of optic nerve impulses when kept in total darkness. Peak activity on the first day of isolation occurs during the projected " dawn" of the light-dark cycle to which the whole animal had previously been entrained. Eyes from animals previously exposed to constant light show a free-running rhythm. This simple photoreceptor provides a quantized output with an ideal control (the other eye) for studies on rhythms.
D000200:Action Potentials; D000818:Animals; D002940:Circadian Rhythm; D003624:Darkness; D008974:Mollusca / Q000502:physiology*; D009799:Ocular Physiological Phenomena; D009900:Optic Nerve / Q000502:physiology*; D012623:Seawater