Department of Anatomy and Neurobiology, Virginia Commonwealth University, Richmond, VA, USA.
Adv Neurobiol. 2023;29:41-64. doi: 10.1007/978-3-031-12390-0_2.
The central nervous system is the last major organ system in the vertebrate body to yield its cellular structure, due to the complexity of its cells and their interactions. The fundamental unit of the nervous system is the neuron, which forms complex circuits that receive and integrate information and generate adaptive responses. Each neuron is composed of an input domain consisting of multiple dendrites along with the cell body, which is also responsible for the majority of macromolecule synthesis for the cell. The output domain is the axon which is a singular extension from the cell body that propagates the action potential to the synapse, where signals pass from one neuron to another. Facilitating these functions are cohorts of supporting cells consisting of astrocytes, oligodendrocytes and microglia along with NG2 cells and ependymal cells. Astrocytes have a dazzling array of functions including physical support, maintenance of homeostasis, development and integration of synaptic activity. Oligodendrocytes form the myelin sheath which surrounds axons and enables rapid conduction of the nerve impulse. Microglia are the resident immune cells, providing immune surveillance and remodeling of neuronal circuits during development and trauma. All these cells function in concert with each other, producing the remarkably diverse functions of the nervous system.
中枢神经系统是脊椎动物体内最后一个产生细胞结构的主要器官系统，这是由于其细胞及其相互作用的复杂性所致。神经系统的基本单位是神经元，它形成复杂的电路，接收和整合信息并产生适应性反应。每个神经元由一个输入域组成，该输入域由多个树突以及细胞体组成，细胞体还负责细胞内大多数大分子的合成。输出域是轴突，它是从细胞体延伸出的单个延伸部分，将动作电位传播到突触，信号从一个神经元传递到另一个神经元。促进这些功能的是由星形胶质细胞、少突胶质细胞和小胶质细胞以及 NG2 细胞和室管膜细胞组成的支持细胞群。星形胶质细胞具有令人眼花缭乱的多种功能，包括物理支持、维持内稳态、发育和整合突触活动。少突胶质细胞形成髓鞘，围绕轴突，使神经冲动能够快速传导。小胶质细胞是常驻免疫细胞，在发育和创伤过程中提供免疫监视和神经元回路的重塑。所有这些细胞协同工作，产生神经系统的显著多样化功能。
