Astrocytes, the most abundant glial cells in the brain, secrete various neurotrophic factors such as brain-derived neurotrophic factor (BDNF) and glial-derived neurotrophic factor (GDNF), which support neuronal survival, growth, and synaptic plasticity. They also release glutamate and other neurotransmitters, modulating synaptic transmission and contributing to the blood-brain barrier. Additionally, astrocytes produce extracellular matrix components and cytokines that regulate inflammation and tissue repair.
Oligodendrocytes, responsible for myelinating central nervous system axons, release factors like myelin-associated glycoprotein (MAG) and oligodendrocyte myelin glycoprotein (OMgp), which influence axonal growth and repair. They also secrete neurotrophic factors that promote neuronal health, particularly in conditions affecting myelin integrity, such as multiple sclerosis.
Microglia, the resident immune cells of the central nervous system, produce pro-inflammatory and anti-inflammatory cytokines, chemokines, and reactive oxygen species in response to injury or infection. They also release factors that modulate synaptic pruning and neurogenesis, contributing to learning and memory. Dysregulated microglial activity is implicated in neurodegenerative diseases, including Alzheimer’s and Parkinson’s diseases.
Schwann cells, the glial cells of the peripheral nervous system, secrete neurotrophic factors like nerve growth factor (NGF) and GDNF, which support axonal regeneration and neuronal survival. They also produce extracellular matrix proteins that guide axonal growth and repair following injury.
Collectively, glial-derived factors influence neuronal development, synaptic function, and repair mechanisms, highlighting their essential role in both normal brain physiology and pathological conditions. Understanding these interactions is critical for developing therapeutic strategies targeting glial cell function in neurological disorders.