|
|
||||||||
ENVIRONMENTAL, EXERCISE AND RESPIRATORY PHYSIOLOGY
ULP-CNRS UMR 7518, Neurobiologie des Rythmes, IFR Neurosciences 37, Strasbourg, France
Submitted 15 January 2004 ; accepted in final form 16 August 2004
In the Syrian hamster, winter seasonal inhibition of reproduction occurs in response to decreasing day length. This inhibitory response is modulated by nonphotic cues. In particular, access to a running wheel has been shown to produce incomplete gonadal regression. The present study sought to determine whether this occurs as a consequence of wheel effect on adaptation of the circadian system to short days or whether downstream physiological responses are involved. Short-day adaptation of the circadian clock, which is located in the suprachiasmatic nucleus (SCN) of the hypothalamus, was tested by lengthening the photosensitive phase of the SCN (assayed by light-induced c-Fos expression in the SCN) as a parameter. We found that wheel-running activity does not inhibit the integration of the photoperiodic change by the SCN even if complete testicular regression is prevented. Moreover, this exercise was even capable of accelerating the lengthening of the photosensitive phase after the transfer to short day length. Thus, although wheel-running activity inhibits the short photoperiod-induced gonadal regression, it acts on the SCN to accelerate the integration of the photoperiodic change by the biological clock.
c-fos; wheel-running activity
This article has been cited by other articles:
![]() |
H. N. Jones, L. A. Woollett, N. Barbour, P. D. Prasad, T. L. Powell, and T. Jansson High-fat diet before and during pregnancy causes marked up-regulation of placental nutrient transport and fetal overgrowth in C57/BL6 mice FASEB J, January 1, 2009; 23(1): 271 - 278. [Abstract] [Full Text] [PDF] |
||||
![]() |
F. Scherbarth, J. Rozman, M. Klingenspor, G. Brabant, and S. Steinlechner Wheel running affects seasonal acclimatization of physiological and morphological traits in the Djungarian hamster (Phodopus sungorus) Am J Physiol Regulatory Integrative Comp Physiol, September 1, 2007; 293(3): R1368 - R1375. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |