細胞描述
The tissue of the central nervous system is made up of two classes of cells that may be broadly categorized as neurons and glia. Neurons are anatomic, functional, and trophic units of the brain [1]. Despite great variability in size and shape, all neurons share common morphological features, the key elements of a highly complex communication network. Neurons are dynamically polarized cells that serve as the major signaling unit of the nervous system. The brain contains about 1 x 1011 neurons, each being able to contact at least 10,000 other neurons [2].