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Exposure of male Syrian hamsters to a short daylength of 8L:16D leads to gonadal regression. This effect of photoperiod was prevented by pinealectomy or chronic exposure of the brain to exogenous melatonin delivered from in-dwelling cannulae. However, the effect of melatonin was dependent on the neural site of application. Melatonin delivered into the mid-brain, lateral hypothalamus or amygdala was ineffective. In contrast, bilateral administration of melatonin to the medial or amygdala was ineffective. In contrast, bilateral administration of melatonin to the medial hypothalamus prevented testicular regression and maintained high circulating levels of luteinizing hormone and prolactin. These findings suggest that the medial hypothalamus contains target sites for melatonin involved in pineal-mediated photoperiodic responses.
M H Hastings, and
A P Walker, and
A C Roberts, and
J Herbert
April 2001,
Brain research. Molecular brain research,
M H Hastings, and
A P Walker, and
A C Roberts, and
J Herbert
May 1996,
Endocrinology,
M H Hastings, and
A P Walker, and
A C Roberts, and
J Herbert
September 1985,
Journal of reproduction and fertility,
M H Hastings, and
A P Walker, and
A C Roberts, and
J Herbert
October 1999,
Journal of biological rhythms,
M H Hastings, and
A P Walker, and
A C Roberts, and
J Herbert
November 1995,
Journal of neuroendocrinology,
M H Hastings, and
A P Walker, and
A C Roberts, and
J Herbert
June 1996,
Journal of neuroendocrinology,
M H Hastings, and
A P Walker, and
A C Roberts, and
J Herbert
January 1979,
Endocrinology,
M H Hastings, and
A P Walker, and
A C Roberts, and
J Herbert
July 1985,
Neuroendocrinology,
M H Hastings, and
A P Walker, and
A C Roberts, and
J Herbert
May 1981,
Neuroscience letters,
M H Hastings, and
A P Walker, and
A C Roberts, and
J Herbert
February 1979,
Endocrinology,
