Electrical Stimulation of the Hypothalamic Paraventricular Nuclei Inhibits Pineal Melatonin Synthesis in Male Rats
作者:
Stefan Reuss,
James Olcese,
Lutz Vollrath,
期刊:
Neuroendocrinology
(Karger Available online 1985)
卷期:
Volume 41,
issue 3
页码: 192-196
ISSN:0028-3835
年代: 1985
DOI:10.1159/000124177
出版商: S. Karger AG
关键词: Electrical stimulation;Melatonin;Paraventricular nucleus;Pineal;Rat
数据来源: Karger
摘要:
Recent findings have shown that lesions of the hypothalamic paraventricular nuclei (PVN) disrupt the synthesis of melatonin in the rat pineal gland. In order to further clarify the role of the PVN in the control of pineal function, the effects of electrical stimulation of these nuclei were investigated in acutely blinded adult male Sprague-Dawley rats. Following electrical stimulation, pineal serotonin-N-acetyltransferase (NAT) activity and pineal melatonin content were measured by means of radioenzymatic and radioimmunoassay methods, respectively. Stimulation had no significant effect on pineal melatonin synthesis throughout the early part of the dark phase, but caused a significant reduction in NAT activity during the light phase and the latter part of the dark phase. The pineal melatonin content appeared reduced, but due to large individual variations this reduction was not statistically significant. Stimulation duration experiments reveal that reduction of NAT activity is time dependent, with significant inhibition occurring after 30 min of stimulation. These observations further support the involvement of the PVN in the melatonin rhythm generating pathway and suggest that electrical activation of fibers in the PVN is similar to the effects of light on pineal melatonin synthesis.
点击下载:
PDF
(1052KB)
返 回