Fu Y, Yu Y, Paxinos G, Watson C, Rusznák Z
Neuroscience Research Australia, Sydney, NSW 2031, Australia; The University of New South Wales, Sydney, NSW 2052, Australia.
Neuroscience Research Australia, Sydney, NSW 2031, Australia.
Neuroscience. 2015 Apr 2;290:406-20. doi: 10.1016/j.neuroscience.2015.01.039. Epub 2015 Jan 29.
Although the impact of aging on the function of the central nervous system is known, only a limited amount of information is available about accompanying changes affecting the cellular composition of the brain and spinal cord. In the present work we used the isotropic fractionator method to reveal aging-associated changes in the numbers of neuronal and non-neuronal cells harbored by the brain and spinal cord. The experiments were performed on 15-week, 7-month, 13-month, and 25-month-old female mice. The major parts of the brain were studied separately, including the isocortex, hippocampus, cerebellum, olfactory bulb, and the remaining part (i.e., 'rest of brain'). The proliferative capacity of each structure was assessed by counting the number of Ki-67-positive cells. We found no aging-dependent change when the cellular composition of the isocortex was studied. In contrast, the neuronal and non-neuronal cell numbers of the hippocampus decreased in the 7-25-month period. The neuronal cell number of the olfactory bulb showed positive age-dependence between 15 weeks and 13 months of age and presented a significant decrease thereafter. The cerebellum was characterized by an age-dependent decrease of its neuronal cell number and density. In the rest of brain, the non-neuronal cell number increased with age. The neuronal and non-neuronal cell numbers of the spinal cord increased, whereas its neuronal and non-neuronal densities decreased with age. The number of proliferating cells showed a marked age-dependent decrease in the hippocampus, olfactory bulb, and rest of the brain. In contrast, the number of Ki-67-positive cells increased with age in both the cerebellum and spinal cord. In conclusion, aging-dependent changes affecting the cellular composition of the mouse central nervous system are present but they are diverse and region-specific.
虽然衰老对中枢神经系统功能的影响已为人所知，但关于影响脑和脊髓细胞组成的伴随变化的信息却十分有限。在本研究中，我们使用各向同性分选法来揭示脑和脊髓中神经元和非神经元细胞数量与衰老相关的变化。实验在15周龄、7月龄、13月龄和25月龄的雌性小鼠身上进行。分别对脑的主要部分进行了研究，包括同型皮质、海马体、小脑、嗅球以及其余部分（即“脑的其余部分”）。通过计数Ki-67阳性细胞的数量来评估每个结构的增殖能力。当研究同型皮质的细胞组成时，我们未发现与衰老相关的变化。相比之下，在7至25月龄期间，海马体中的神经元和非神经元细胞数量减少。嗅球的神经元细胞数量在15周龄至13月龄之间呈现出与年龄正相关，此后则显著减少。小脑的特征是其神经元细胞数量和密度随年龄增长而减少。在脑的其余部分，非神经元细胞数量随年龄增加。脊髓的神经元和非神经元细胞数量增加，而其神经元和非神经元密度随年龄降低。增殖细胞的数量在海马体、嗅球和脑的其余部分呈现出明显的与年龄相关的减少。相比之下，小脑和脊髓中Ki-67阳性细胞的数量随年龄增加。总之，存在影响小鼠中枢神经系统细胞组成的与衰老相关的变化，但这些变化是多样的且具有区域特异性。
