Neuropeptide Y in the circadian timing system.
Neuropeptide Y in the circadian timing system.
复制标题
昼夜节律计时系统中的神经肽 Y。
DOI：
10.1111/j.1749-6632.1990.tb48936.x
复制
发表时间：
1990
影响因子：
5.2
通讯作者：
Card,JP
中科院分区：
文献类型：
--
作者：
Moore,RY;Card,JP
Circadian rhythms are adaptations to the solar cycle of light and dark. In mammals, circadian rhythms express a temporal organization of physiological processes and behavior that results in optimal animal adaptation. The essential features of circadian rhythms are that they are generated by endogenous pacemakers and continuously reset, a process termed" entrainment." by the light-dark cycle. This generation and entrainment of circadian rhythms is accomplished by a set of central neural structures, the circadian timing system (CTS). The principal components of the CTS are visual pathways mediating entrainment, pacemakers and efferent projections from the pacemakers to effector systems that exhibit circadian function (FIG. I).Over the last twenty years there has been a rapid accumulation of information about the organization and function of the CTS (cf. Rusak and Zucker'and Meijer and Rietveld2 for reviews that reflect this progress). The essential features of the CTS, as we now understand it, are as follows. The lateral eyes are necessary for entrainment. Light activates retinal photoreceptors which are coupled through the usual retinal circuitry to a specific set of ganglion cells, probably a subgroup of W cells, 3 responding predominantly to changes in luminous flux. These cells appear to project in both the lateral geniculate complex and to the suprachiasmatic nuclei (SCN) of the hypothalamus. 4 The projection to the SCN has been designated the retinohypothalamic tract (RHT). Early studies using the autoradiographic tracing method"-found only projections to the SCN but more recent studies, using sensitive anterograde lectin transport methods, have shown projections to the anterior hypothalamus, lateral hypothalamus and retrochiasmatic area as well as to the SCN.'The function of the projections beyond the SCN is unclear at this time but there is substantial evidence to establish that the RI-T to the SCN is sufficient to maintain entrainment in the absence of other visual projections.'." The SCN is a circadian pacemaker (FIG. 2). Three lines of evidence support that conclusion. First, ablation of the SCN results in a loss of circadian rhythms.. 12.2 There are individual studies from which it is concluded that one or another rhythm, usually the
