Melatonin inhibits in vitro serotonergic phase shifts of the suprachiasmatic circadian clock.
Melatonin inhibits in vitro serotonergic phase shifts of the suprachiasmatic circadian clock.
复制标题
褪黑素在体外抑制视交叉上生物钟的血清素能相移。
DOI：
10.1016/s0006-8993(98)01295-5
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发表时间：
1999
期刊：
影响因子：
2.9
通讯作者：
Prosser,RA
中科院分区：
文献类型：
--
作者：
Prosser,RA
视交叉上（SCN）昼夜节律起搏器产生24小时的自发神经元活动的节奏时，在急性脑切片制备分离。孤立的起搏点也保留了其被重置的能力，或被外源刺激相移的能力。例如，5-羟色胺（5-HT）激动剂在主观日中期期间应用时推进SCN起搏器，而神经肽Y（NPY）激动剂和褪黑激素在主观日晚期期间应用时推进起搏器。先前的工作已经证明了NPY和5-HT激动剂之间的相互作用，使得NPY可以阻断5-HT能相的进展，而5-HT激动剂不能阻止NPY诱导的进展。由于褪黑激素和NPY在SCN中的作用有许多相似之处，褪黑激素和5-HT似乎也可能在SCN中相互作用。因此，在这项研究中，褪黑激素和5-HT激动剂之间的潜在相互作用进行了探讨。褪黑激素抑制5-HT激动剂（+）DPAT的相位提前，这种抑制作用被河豚毒素的共同应用所减弱。相反，褪黑激素不能阻止环AMP类似物8BA-cAMP的相位推进。最后，5-HT激动剂和8 BA-AMP都不能阻断褪黑素诱导的相位提前。这些结果表明，在SCN的褪黑激素和5-HT之间的明确的相互作用，并建议，褪黑激素和NPY可能发挥类似的作用，在调制大鼠SCN的昼夜节律起搏器的相位。
The suprachiasmatic (SCN) circadian pacemaker generates 24 h rhythms of spontaneous neuronal activity when isolated in an acute brain slice preparation. The isolated pacemaker also retains its capacity to be reset, or phase-shifted by exogenous stimuli. For example, serotonin (5-HT) agonists advance the SCN pacemaker when applied during mid subjective day, while neuropeptide Y (NPY) agonists and melatonin advance the pacemaker when applied during late subjective day. Previous work has demonstrated interactions between NPY and 5-HT agonists, such that NPY can block 5-HTergic phase advances, while 5-HT agonists do not prevent NPY-induced advances. Due to a number of similarities in the actions of melatonin and NPY in the SCN, it seemed possible that melatonin and 5-HT might interact in the SCN as well. Therefore, in this study potential interactions between melatonin and 5-HT agonists were explored. Melatonin inhibited phase advances by the 5-HT agonist, (+)DPAT, and this inhibition was decreased by co-application of tetrodotoxin. Conversely, melatonin was unable to block phase advances by the cyclic AMP analog, 8BA-cAMP. Finally, neither 5-HT agonists nor 8BA-AMP were able to block melatonin-induced phase advances. These results demonstrate a clear interaction between melatonin and 5-HT in the SCN, and suggest that melatonin and NPY may play similar roles with respect to modulating the phase of the SCN circadian pacemaker in rats.