Elston G N, Tweedale R, Rosa M G
Department of Physiology and Pharmacology, University of Queensland, Australia.
Proc Biol Sci. 1999 Jul 7;266(1426):1367-74. doi: 10.1098/rspb.1999.0789.
Layer III pyramidal neurons were injected with Lucifer yellow in tangential cortical slices taken from the inferior temporal cortex (area TE) and the superior temporal polysensory (STP) area of the macaque monkey. Basal dendritic field areas of layer III pyramidal neurons in area STP are significantly larger, and their dendritic arborizations more complex, than those of cells in area TE. Moreover, the dendritic fields of layer III pyramidal neurons in both STP and TE are many times larger and more complex than those in areas forming 'lower' stages in cortical visual processing, such as the first (V1), second (V2), fourth (V4) and middle temporal (MT) visual areas. By combining data on spine density with those of Sholl analyses, we were able to estimate the average number of spines in the basal dendritic field of layer III pyramidal neurons in each area. These calculations revealed a 13-fold difference in the number of spines in the basal dendritic field between areas STP and V1 in animals of similar age. The large differences in complexity of the same kind of neuron in different visual areas go against arguments for isopotentiality of different cortical regions and provide a basis that allows pyramidal neurons in temporal areas TE and STP to integrate more inputs than neurons in more caudal visual areas.
在取自猕猴颞下皮质（TE区）和颞上多感觉区（STP区）的切线状皮质切片中，对第III层锥体神经元注射了荧光黄。与TE区的细胞相比，STP区第III层锥体神经元的基底树突野面积显著更大，其树突分支也更复杂。此外，STP区和TE区第III层锥体神经元的树突野比在皮质视觉处理中形成“较低”阶段的区域（如第一视觉区（V1）、第二视觉区（V2）、第四视觉区（V4）和颞中区（MT））的神经元树突野大许多倍且更复杂。通过将棘密度数据与肖尔分析数据相结合，我们能够估算出每个区域第III层锥体神经元基底树突野中棘的平均数量。这些计算结果显示，在年龄相似的动物中，STP区和V1区之间基底树突野中棘的数量相差13倍。不同视觉区域中同类型神经元在复杂性上的巨大差异与不同皮质区域等势性的观点相悖，并为颞区TE和STP中的锥体神经元比更靠后的视觉区域中的神经元整合更多输入提供了依据。
