Department of Psychology, Vanderbilt University Nashville, TN, USA.
Front Neuroanat. 2014 May 16;8:36. doi: 10.3389/fnana.2014.00036. eCollection 2014.
Determining the cellular composition of specific brain regions is crucial to our understanding of the function of neurobiological systems. It is therefore useful to identify the extent to which different methods agree when estimating the same properties of brain circuitry. In this study, we estimated the number of neuronal and non-neuronal cells in the primary visual cortex (area 17 or V1) of both hemispheres from a single chimpanzee. Specifically, we processed samples distributed across V1 of the right hemisphere after cortex was flattened into a sheet using two variations of the isotropic fractionator cell and neuron counting method. We processed the left hemisphere as serial brain slices for stereological investigation. The goal of this study was to evaluate the agreement between these methods in the most direct manner possible by comparing estimates of cell density across one brain region of interest in a single individual. In our hands, these methods produced similar estimates of the total cellular population (approximately 1 billion) as well as the number of neurons (approximately 675 million) in chimpanzee V1, providing evidence that both techniques estimate the same parameters of interest. In addition, our results indicate the strengths of each distinct tissue preparation procedure, highlighting the importance of attention to anatomical detail. In summary, we found that the isotropic fractionator and the stereological optical fractionator produced concordant estimates of the cellular composition of V1, and that this result supports the conclusion that chimpanzees conform to the primate pattern of exceptionally high packing density in V1. Ultimately, our data suggest that investigators can optimize their experimental approach by using any of these counting methods to obtain reliable cell and neuron counts.
确定特定脑区的细胞组成对于我们理解神经生物学系统的功能至关重要。因此，确定不同方法在估计脑回路相同特性时的一致性程度是很有用的。在这项研究中，我们从一只黑猩猩的两个半球的初级视觉皮层（区域 17 或 V1）中估计了神经元和非神经元细胞的数量。具体来说，我们使用两种各向同性分馏器细胞计数方法，将右半球的皮层平铺成薄片后，对 V1 中的样本进行处理。我们将左半球作为连续脑切片进行立体学研究。本研究的目的是通过比较单个个体的一个感兴趣脑区的细胞密度估计值，以最直接的方式评估这些方法之间的一致性。在我们的研究中，这些方法对黑猩猩 V1 中的总细胞群体（约 10 亿）和神经元数量（约 6.75 亿）的估计值相似，这表明这两种技术都估计了相同的感兴趣参数。此外，我们的结果表明了每种不同组织准备程序的优势，突出了对解剖细节的关注的重要性。总之，我们发现各向同性分馏器和立体学光学分馏器对 V1 的细胞组成产生了一致的估计，这一结果支持了黑猩猩符合 V1 中异常高包装密度的灵长类模式的结论。最终，我们的数据表明，研究人员可以通过使用这些计数方法中的任何一种来获得可靠的细胞和神经元计数，从而优化他们的实验方法。
