Oliver D L, Kuwada S, Yin T C, Haberly L B, Henkel C K
Department of Anatomy, University of Connecticut Health Center, Farmington 06032.
J Comp Neurol. 1991 Jan 1;303(1):75-100. doi: 10.1002/cne.903030108.
The dendritic and axonal morphology of neurons in the inferior colliculus of the cat was investigated after intracellular injection of HRP, in vivo. All injected axons gave off local collaterals, and most showed a widespread distribution and lacked a specific orientation. In contrast, the dendrites of injected neurons were distinguished by their degree of orientation and the direction of the longest axis of orientation. Dendrites showed a high, moderate, or low degree of orientation. Most highly oriented cells had their longest axis in the rostrocaudal direction with fewer in the mediolateral direction. In the central nucleus, only the rostrocaudally oriented cells correspond to the disc-shaped cells identified in Golgi preparations. Unlike most cells in our sample, the two cells that were disc-shaped had axons that were parallel to the orientation of the dendritic tree. In the dorsal cortex, rostrocaudally oriented cells also were found, but they had unoriented axons. In both the central nucleus and dorsal cortex, cells with a mediolateral axis of orientation or no specific orientation correspond to stellate cells and had axons with widespread local collaterals. These results suggest that an extensive network of local axon collaterals may contribute to neural processing within the inferior colliculus. In the central nucleus, local axons may establish connections within or across the fibrodendritic laminae. In the dorsal cortex, the local and afferent axons may form a complex reticular network. Finally, some injected cells had axons terminating locally and also entering the brachium of the inferior colliculus. This suggests that cells in the inferior colliculus may function as both interneurons and projection neurons.
在猫体内，通过细胞内注射辣根过氧化物酶（HRP），对下丘神经元的树突和轴突形态进行了研究。所有注射的轴突均发出局部侧支，且大多数侧支分布广泛且缺乏特定的取向。相比之下，注射神经元的树突则以其取向程度和最长取向轴的方向为特征。树突表现出高、中或低程度的取向。大多数高度取向的细胞其最长轴位于前后方向，而位于中外侧方向的较少。在中央核中，只有前后取向的细胞与高尔基染色标本中鉴定出的盘状细胞相对应。与我们样本中的大多数细胞不同，这两个盘状细胞的轴突与树突树的取向平行。在背侧皮质中，也发现了前后取向的细胞，但它们的轴突没有取向。在中央核和背侧皮质中，具有中外侧取向轴或无特定取向的细胞对应于星状细胞，并且其轴突具有广泛的局部侧支。这些结果表明，广泛的局部轴突侧支网络可能有助于下丘内的神经处理。在中央核中，局部轴突可能在纤维树突层内或跨层建立连接。在背侧皮质中，局部轴突和传入轴突可能形成复杂的网状网络。最后，一些注射的细胞其轴突在局部终止，同时也进入下丘臂。这表明下丘中的细胞可能兼具中间神经元和投射神经元的功能。
