Glial Cells |
Glial cells and NeuroDevelopment- The Neural System |
| Glial cells - Myelination, myelogenesis and myelogenetic cycles |
| Glial cell development and myelogenetic cycles |
| Glial cells include: astrocytes, oligodendrocytes, microglia
Functions of glial cells are: myelination; respond to injury; regulate neuronal metabolism, contributing to BBB; Glial cells are relatively immature in early stages of CNS development (no gliosis to penetrating wound in newborn brain) Most important role is myelination. |
MyelinationMyelination play a main role in electrical activity Myelination of regions correlates with emergence of function. Myelination starts in spinal cord, spreads to medulla, pons, midbrain, finally to diencephalon and telencephalon. Cortical regions myelination begins posterior and moves anterior, with parietal and frontal lobes last. Frontal and parietal myelination begins after birth and continues to adolescence and adulthood. Increase in brain weight postnatally primarily myelination. |
MyelogenesisWhat is Myelogenesis? Is the process of development of myelin. Primordial (premature) fields myelinate before birth, somesthetic cortex, primary visual cortex, primary auditory cortex. Intermediate (postmature) fields myelinate during first 3 postnatal months, named secondary association areas. Terminal fields myelinate between fourth postnatal month and 14 yrs of age, called classical association areas. |