title: Introduction to cells comprising the nervous system.
abstract: The brain consists of neurons and glial cells. Neurons are responsible for integrating input and responding to stimuli from both the internal and the external environment. The integration occurs via electrical and chemical signals that impinge on the receptive area of neurons known as dendrites, and the response is via propagation of an axonal potential. Glial cells have three functionally distinct subtypes, astrocytes, oligodendrocytes, and microglia. Astrocytes perform a variety of functions responsible for maintaining homeostasis in the brain through functions such as formation of the blood-brain barrier, preserving osmolarity, and the uptake, degradation, and secretion of neurotransmitters. Oligodendrocytes are responsible for the production of myelin, a lipid-rich substance that encapsulates neuronal axons. Microglia are responsible for immune surveillance and remodeling of the CNS during both normal development and injury. Together the cells of the brain form a highly metabolic and dynamic unit with robust requirements for oxygen and nutrients.
authors.affiliation: Department of Neurosurgery, Penn State Milton S. Hershey Medical Center, 500 University Drive, 850, Hershey, PA, 17033, USA.
authors.forename: Douglas G
authors.initials: DG
authors.lastname: Peters
authors.forename: James R
authors.initials: JR
authors.lastname: Connor