EFFECTS OF EFFERENT ACTIVITY ON ENTRAINMENT OF THE APLYSIA EYE

1. 1. The effects of efferent optic nerve activity on the speed of entrainment of the ocular oscillators in Aplysia were investigated by severing one optic nerve in 21 animals and evaluating reentrainment rates to a light cycle phase advanced 10hr in relation to a prior light schedule. 2. 2. Reentrainment to this phase advanced light cycle was essentially complete in both the intact and denervated eyes within 3 days; and there was no indication that the time course of entrainment was significantly different in the two eyes. 3. 3. The phase angle of the rhythm of neurally isolated eyes, however, consistently phase led the intact eyes by approx 1 hr. Thus, the results indicate that while efferent activity does not significantly effect the speed of entrainment, it appears to influence steady-state phase angle. © 1979.