Pickard G E
J Comp Neurol. 1982 Oct 10;211(1):65-83. doi: 10.1002/cne.902110107.
The afferent connections of the hypothalamic suprachiasmatic nucleus (SCN) of the golden hamster were examined using horseradish peroxidase (HRP) as the retrograde tracer molecule. Unilateral iontophoretic deposition of HRP into the SCN labeled ganglion cells bilaterally in the retinae. The labeled ganglion cells all had large somata and were randomly distributed across the retina. A similar number were labeled in each retina, which contrasted with the findings from injections into the optic chiasm and lateral geniculate body. Chiasm and geniculate injections both labeled three classes of ganglion cell (small, large, and giant) predominantly in the contralateral retinae. Telencephalic afferent projections to the SCN included the ventral subicular cortex and the septum. Notable diencephalic afferents included the dorsal lamina of the internal division of the ventral lateral geniculate nucleus (vLGN); the ipsilateral input was twice that of the contralateral projection. The same region of the vLGN was also noted to be reciprocally connected to the contralateral vLGN. The thalamic paraventricular nucleus was also heavily labeled but only ipsilaterally. Of functional significance, the SCN was discovered to innervate its contralateral homologue. Other less numerous afferents in the midbrain included the dorsal and median raphe nuclei and the dorsal nucleus of the lateral lemniscus. The afferent projections to the SCN determined in this study are discussed in regard to the known physiological role of the SCN as part of the circadian clock system.
利用辣根过氧化物酶（HRP）作为逆行示踪分子，研究了金黄仓鼠下丘脑视交叉上核（SCN）的传入连接。将HRP单侧离子导入SCN，双侧视网膜中的神经节细胞被标记。被标记的神经节细胞均具有大的胞体，且在视网膜上随机分布。每个视网膜中被标记的细胞数量相似，这与向视交叉和外侧膝状体注射的结果形成对比。视交叉和外侧膝状体注射均主要在对侧视网膜中标记出三类神经节细胞（小、大、巨型）。向SCN的端脑传入投射包括腹侧下托皮质和隔区。显著的间脑传入包括腹侧外侧膝状核（vLGN）内部分的背层；同侧输入是对侧投射的两倍。还注意到vLGN的同一区域与对侧vLGN相互连接。丘脑室旁核也被大量标记，但仅为同侧。具有功能意义的是，发现SCN支配其对侧同源物。中脑其他数量较少的传入包括背侧和中缝核以及外侧丘系背核。结合SCN作为昼夜节律时钟系统一部分的已知生理作用，讨论了本研究中确定的向SCN的传入投射。
