A Caltech Library Service

Circadian Rhythm of Neuron R15 of Aplysia californica: In vivo Photoentrainment

Audesirk, Gerald and Strumwasser, Felix (1975) Circadian Rhythm of Neuron R15 of Aplysia californica: In vivo Photoentrainment. Proceedings of the National Academy of Sciences of the United States of America, 72 (6). pp. 2408-2412. ISSN 0027-8424.

See Usage Policy.


Use this Persistent URL to link to this item:


(1) The neuron R15 in the parietovisceral ganglion of Aplysia has a circadian rhythm of spiking activity when recorded in the isolated ganglion. The rhythm is entrained in vivo by light-dark cycles. (2) The phase of the R15 rhythm is a function not only of the entraining light schedule, but also of the time of dissection. Changes in the dissection time during the light portion of the light-dark cycle yield little change in the subsequent R15 peak time. Dissections during the dark portion produce peak times that vary with dissection time with a slope that is approximately one. (3) The circadian rhythm of R15 can be phase-shifted in vivo by changes in the phase of the entraining light-dark cycle in one to two weeks. R15 neurons of blinded Aplysia, however, show little or no phase shift in this time. (4) It is concluded that the eyes are important as receptors for the photoentrainment of the R15 rhythm in vivo, but that neural connections from the eyes to R15 are not required.

Item Type:Article
Related URLs:
URLURL TypeDescription
Additional Information:Copyright © 1975 by the National Academy of Sciences Communicated by Colin S. Pittendrigh, April 10, 1975 This work was supported by a National Science Foundation predoctoral fellowship to G.A., by a National Institutes of Health Predoctoral Training Grant and by National Institutes of Health Grant NS07071 and a grant from the Alfred P. Sloan Foundation to F.S. We would like to thank Drs. Serge Daan and Colin Pittendrigh for their critical reading of this manuscript.
Subject Keywords:effects of dissection time; role of eyes in photoentrainment
Issue or Number:6
Record Number:CaltechAUTHORS:AUDpnas75
Persistent URL:
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:6961
Deposited By: Archive Administrator
Deposited On:03 Jan 2007
Last Modified:02 Oct 2019 23:37

Repository Staff Only: item control page