Chapter 14, Problem 1DQ

Summary Introduction

To review:

During the CNS development whether oligodendrocyte wrapping is essential for neuronal survival or not, and the targeting of synaptic partners is regulated by astroglial cells or not. Also explain whether microglia help “scult” the brain during the development.

Introduction:

Glia also known as glial cells or neuroglia. These are the non neuronal cells present in the central nervous system and peripheral nervous system. Three types of glial cells are present in the central nervous system, named as oligodendrocytes, astroglia and microglia. The transmission of information in neurons takes place via the electric impulses that travel from one part of the body to another along the axons. These cells are important in maintaining the homeostasis and protection of neurons.

Explanation of Solution

Oligodendrocytes are the important glial cells which provide the insulation to axons in central nervous system. This insulation process prevents the dispersal of the electric signal and also enhance the conduction towards the target cells. The wrapping process involves the generation of mylein sheath by the oligodendrocytes. This mylein sheath is 80% lipid and 20% protein. The presence of mylein sheath is essential for the proper functioning of nerve cells. This mylein wrapping also leads to the longevity in axons for decades.

Astroglial cells named because of their “star shape”. These cells are most abundant cells present in the brain and regulates the electrical impulse transmission within the brain. The crucial role of astrocytes, is maintainence of proper health and function of the nervous system by providing the metabolic and tropic support to neurons. These cells acts as a critical regulator of brain development via the bidirectional interaction with the neuronal synpases. These cell's processes also helps in removal of synaptically released neurotransmitters from the interstitial space, thus avoid the accumulation of neurotransmitter, so important for the homeostasis.

Microglia also play an important role as “immune cells” of the central nervous system. These cells perform their function by the process of phagocytosis and behave like the macrophages. Thus essential to maintain a good health of the CNS.

Conclusion

Thus it is concluded that oligodendrocyte wrapping is essential for neuronal survival, the targeting of synaptic partners is regulated by astroglial cells and microglia helps in “scult” the brain during the development.