Institute of Biomedical Sciences, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil.
D'Or Institute for Research and Education, Rio de Janeiro, Brazil.
Cereb Cortex. 2023 Jun 20;33(13):8654-8666. doi: 10.1093/cercor/bhad148.
The human cerebral cortex is one of the most evolved regions of the brain, responsible for most higher-order neural functions. Since nerve cells (together with synapses) are the processing units underlying cortical physiology and morphology, we studied how the human neocortex is composed regarding the number of cells as a function of sex and age. We used the isotropic fractionator for cell quantification of immunocytochemically labeled nuclei from the cerebral cortex donated by 43 cognitively healthy subjects aged 25-87 years old. In addition to previously reported sexual dimorphism in the medial temporal lobe, we found more neurons in the occipital lobe of men, higher neuronal density in women's frontal lobe, but no sex differences in the number and density of cells in the other lobes and the whole neocortex. On average, the neocortex has ~10.2 billion neurons, 34% in the frontal lobe and the remaining 66% uniformly distributed among the other 3 lobes. Along typical aging, there is a loss of non-neuronal cells in the frontal lobe and the preservation of the number of neurons in the cortex. Our study made possible to determine the different degrees of modulation that sex and age evoke on cortical cellularity.
人类大脑皮层是大脑中进化程度最高的区域之一，负责大多数高级神经功能。由于神经细胞（连同突触）是皮质生理学和形态学的基础处理单元，我们研究了人类新皮层在性别和年龄方面是如何由细胞数量构成的。我们使用各向同性分馏器对来自 43 名认知健康的 25-87 岁捐赠者大脑皮层的免疫细胞化学标记核进行细胞定量。除了先前报道的在颞叶内侧的性别二态性之外，我们还发现男性的枕叶神经元更多，女性额叶的神经元密度更高，但在其他叶和整个新皮层的细胞数量和密度方面没有性别差异。平均而言，新皮层有~102 亿个神经元，34%在额叶，其余 66%均匀分布在其他 3 个叶中。随着典型的衰老，额叶中的非神经元细胞丢失，而皮层中的神经元数量保持不变。我们的研究使我们能够确定性别和年龄对皮质细胞数量的不同调节程度。
