Structural Biochemistry/Glial Cells

Glial Cells (Neuroglial Cells) provide the support, stability, and insulation for neurons. These cells have no role in relaying information but are crucial for the survival of neurons. Glial cells are most abundant in the nervous system with a glial to neuron ratio of approximately 3:1. They are generally smaller in size and do not consist of axons or dendrites. Three types of glial cells exist in a developed central nervous system – astrocytes, oligodendrocytes, and microglial cells.

Astrocytes
Astrocytes are star-shaped glial cells that exist only in the central nervous system. These glial cells are used to maintain the best chemical environment for neurons. Astrocytes also help regulate signaling of the neurons by breakdowns of neurotransmitters.

Oligodendrocytes
Oligodendrocytes act as myelin. This helps with neuro signaling because it speeds up the process. Signals travel faster down myelinated axons. Again, oligodendrocytes exist in the central nervous system.

Microglial
Microglial cells remove cellular waste products from areas of injury or cell death. It helps remove unwanted debris that takes up unnecessary space. These cells are often known as macrophages because of their functional similarities. During head injuries, microglial cells increase in number to help remove the dead cells.

Effects of Glial Cells on Depression
After careful analysis of depressed patients’ brain (post mortem), it was discovered that these patients had fewer amounts of glial cells. This caused imbalances in the chemical environment and restricts proper neuro communications. Elsayed and colleagues at Yale University discovered that FGF2 could help produce more glial cells in the brain and reduce the effects of chronic stress. FGF2 (fibroblast growth factor-2 ) was injected in mice that had similar depression symptoms (sadness and loss of interest) and the results showed an increase in glial cell production. This is a newfound discovery for the treatment of depression.