Systematic, Cross-Cortex Variation in Neuron Numbers in Rodents and Primates
Systematic, Cross-Cortex Variation in Neuron Numbers in Rodents and Primates
复制标题
DOI：
10.1093/cercor/bht214
复制
发表时间：
2015-01-01
期刊：
影响因子：
3.7
通讯作者：
Finlay, Barbara L.
中科院分区：
文献类型：
--
作者：
Charvet, Christine J.;Cahalane, Diarmuid J.;Finlay, Barbara L.
在不同物种和不同皮质区域中，每单位皮质表面积神经元数量的均匀性、局部可变性和系统性变化被认为是等皮质的特征。解决这些问题一直很困难，因为不同研究的物种、技术和皮层区域各不相同。我们对啮齿类动物（仓鼠、中棘猴、刺鼠、杜鹃、paca、Cuniculus paca）和灵长类动物（鸮猴、atus trivigratus、绢毛猴、Saguinus midas、卷尾猴、Cebus apella）的皮质表面积单位中II-IV层和V-VI层的神经元数量进行了立体学评估；它们在皮质大小上有系统地变化。评估了物种、皮质区域和技术（立体学、“各向同性分分法”）对神经元估计的贡献。在灵长类动物中，每单位皮质表面积的神经元在吻端-尾端轴上增加（在吻端和尾端轴上的变化系数为1.64-2.13），但在啮齿动物中较少（变化系数为1.15-1.54）。II-IV层神经元是这种变异的主要原因。当整合到物种变异的背景下，以及神经元数量的RC梯度，研究之间的冲突可以被解释。成年期等皮质神经元的RC变化反映了发育中神经发生持续时间的梯度。
Uniformity, local variability, and systematic variation in neuron numbers per unit of cortical surface area across species and cortical areas have been claimed to characterize the isocortex. Resolving these claims has been difficult, because species, techniques, and cortical areas vary across studies. We present a stereological assessment of neuron numbers in layers II-IV and V-VI per unit of cortical surface area across the isocortex in rodents (hamster, Mesocricetus auratus; agouti, Dasyprocta azarae; paca, Cuniculus paca) and primates (owl monkey, Aotus trivigratus; tamarin, Saguinus midas; capuchin, Cebus apella); these chosen to vary systematically in cortical size. The contributions of species, cortical areas, and techniques (stereology, "isotropic fractionator") to neuron estimates were assessed. Neurons per unit of cortical surface area increase across the rostro-caudal (RC) axis in primates (varying by a factor of 1.64-2.13 across the rostral and caudal poles) but less in rodents (varying by a factor of 1.15-1.54). Layer II-IV neurons account for most of this variation. When integrated into the context of species variation, and this RC gradient in neuron numbers, conflicts between studies can be accounted for. The RC variation in isocortical neurons in adulthood mirrors the gradients in neurogenesis duration in development.