Journal of comparative physiology

, Volume 102, Issue 3, pp 251–256

On the role of eyes and brain photoreceptors in the sparrow: Entrainment to light cycles

  • Joseph P. McMillan
  • Henry C. Keatts
  • Michael Menaker
Article

DOI: 10.1007/BF01464359

Cite this article as:
McMillan, J.P., Keatts, H.C. & Menaker, M. J. Comp. Physiol. (1975) 102: 251. doi:10.1007/BF01464359

Summary

The eyes and extraretinal brain photoreceptor(s) of the House Sparrow (Passer domesticus) both contribute to entrainment of the locomotor rhythm. During exposure to a light cycle of low intensity 25 sparrows were entrained and eight free-ran (Table 1). Birds free-running under these conditions became entrained after the intensity of light reaching the brain was increased by plucking their head feathers (Fig. 1). Following carbon black injection beneath the skin over the skull of 23 of these entrained birds, 13 remained entrained and 10 free-ran (Figs. 1 and 2). The injected-entrained birds resynchronized to a 6 hour phase delay in the light cycle. Six of these birds were blinded (bilateral orbital enucleation) and subsequently free-ran. When the carbon black was then removed they re-entrained (Fig. 3).

Copyright information

© Springer-Verlag 1975

Authors and Affiliations

  • Joseph P. McMillan
    • 1
    • 2
  • Henry C. Keatts
    • 1
    • 3
  • Michael Menaker
    • 1
  1. 1.Department of ZoologyUniversity of TexasAustinUSA
  2. 2.College of the Virgin IslandsSt. ThomasUSA
  3. 3.Biology DepartmentSuffolk County Community CollegeSelden, L.I.USA