 |
||||
|
||||
|
||||
|
||||
Previous Article | Next Article
Volume 17, Number 22, Issue of November 15, 1997 pp. 8909-8918
Photoperiodically Driven Changes in Fos Expression within the Basal Tuberal Hypothalamus and Median Eminence of Japanese Quail
Received May 27, 1997; revised Aug. 29, 1997; accepted Sept. 3, 1997.
Simone L. Meddle and Brian K. Follett Biotechnology and Biological Sciences Research Council Group on Photoperiodism & Reproduction, School of Biological Sciences, University of Bristol, Bristol BS8 1UG, United Kingdom
The rapid photoperiodic response in Japanese quail is so precise that it allows neural analyses of how photoperiodic information is transduced into an endocrine response. After transfer from short [SD; 6L:18D (6:18 hr light/dark cycle)] to long (LD; 20L:4D) days, luteinizing hormone (LH) first rises 20 hr after dawn. Using Fos immunocytochemistry, we examined the basal tuberal hypothalamus (BtH) to determine the relationship between brain cell activation and the first endocrine changes. Two separate cell populations within the BtH expressed Fos-like immunoreactivity (FLI) by hour 18 of the first LD. Importantly, this activation occurred before the LH rise. Median eminence activation appeared within glial cells, whereas activated infundibular nucleus cells were neuronal, providing support to the view that gonadotropin-releasing hormone (GnRH) release can be controlled at the terminals by glia. The FLI induction parallels LH changes, suggesting that gene expression may be involved in events preceding photostimulation and is the earliest photoperiodically stimulated physiological change yet reported.
Additional experiments provided further support for this hypothesis. First, photoperiodically induced activation is not a result peculiar to castrates because intact birds displayed similar results. Second, the critical length of 14 hr of light had to be exceeded to cause both BtH activation and a LH rise 30 hr from dawn. Finally, valuable evidence of the response specificity was provided by using a unique property of the quail photoperiodic clock in which exposure to 10L:26D, but not 10L:14D, causes photoinduction. The 36 hr paradigm increased both plasma LH and BtH activation.
Key words: Japanese quail; Coturnix coturnix japonica; photoperiodism; c-fos; glia; luteinizing hormone
This article has been cited by other articles:
N. Nakao, H. Ono, and T. Yoshimura
Thyroid hormones and seasonal reproductive neuroendocrine interactions
Reproduction, July 1, 2008; 136(1): 1 - 8.
[Abstract] [Full Text] [PDF]
J. Balthazart
Activation of Luteinizing Hormone Secretion by Photoperiod and Social Stimuli: Different Paths to the Same Destination
Endocrinology, December 1, 2007; 148(12): 5611 - 5613.
[Full Text] [PDF]
S. Yasuo, T. Yoshimura, S. Ebihara, and H.-W. Korf
Temporal Dynamics of Type 2 Deiodinase Expression after Melatonin Injections in Syrian Hamsters
Endocrinology, September 1, 2007; 148(9): 4385 - 4392.
[Abstract] [Full Text] [PDF]
F. G. Revel, M. Saboureau, P. Pevet, J. D. Mikkelsen, and V. Simonneaux
Melatonin Regulates Type 2 Deiodinase Gene Expression in the Syrian Hamster
Endocrinology, October 1, 2006; 147(10): 4680 - 4687.
[Abstract] [Full Text] [PDF]
S. Yasuo, M. Watanabe, N. Nakao, T. Takagi, B. K. Follett, S. Ebihara, and T. Yoshimura
The Reciprocal Switching of Two Thyroid Hormone-Activating and -Inactivating Enzyme Genes Is Involved in the Photoperiodic Gonadal Response of Japanese Quail
Endocrinology, June 1, 2005; 146(6): 2551 - 2554.
[Abstract] [Full Text] [PDF]
T. Yamamura, K. Hirunagi, S. Ebihara, and T. Yoshimura
Seasonal Morphological Changes in the Neuro-Glial Interaction between Gonadotropin-Releasing Hormone Nerve Terminals and Glial Endfeet in Japanese Quail
Endocrinology, September 1, 2004; 145(9): 4264 - 4267.
[Abstract] [Full Text] [PDF]
M. Watanabe, S. Yasuo, T. Watanabe, T. Yamamura, N. Nakao, S. Ebihara, and T. Yoshimura
Photoperiodic Regulation of Type 2 Deiodinase Gene in Djungarian Hamster: Possible Homologies between Avian and Mammalian Photoperiodic Regulation of Reproduction
Endocrinology, April 1, 2004; 145(4): 1546 - 1549.
[Abstract] [Full Text] [PDF]
G. F. Ball and J. Balthazart
Birds Return Every Spring Like Clockwork, but Where Is the Clock?
Endocrinology, September 1, 2003; 144(9): 3739 - 3741.
[Full Text] [PDF]
S. Yasuo, M. Watanabe, N. Okabayashi, S. Ebihara, and T. Yoshimura
Circadian Clock Genes and Photoperiodism: Comprehensive Analysis of Clock Gene Expression in the Mediobasal Hypothalamus, the Suprachiasmatic Nucleus, and the Pineal Gland of Japanese Quail under Various Light Schedules
Endocrinology, September 1, 2003; 144(9): 3742 - 3748.
[Abstract] [Full Text] [PDF]
S. L. Meddle, D. L. Maney, and J. C. Wingfield
Effects of N-Methyl-D-Aspartate on Luteinizing Hormone Release and Fos-Like Immunoreactivity in the Male White-Crowned Sparrow (Zonotrichia leucophrys gambelii)
Endocrinology, December 1, 1999; 140(12): 5922 - 5928.
[Abstract] [Full Text]
|
|
|
|
 |
|