Oligodendroglia and Myelin: Supporting the Connectome.

Oligodendroglia are the only cell lineage of the central nervous system (CNS) responsible for producing myelin. They originate from precursor cells known as oligodendrocyte precursor cells (OPCs), which are born around the ventricular zones of the brain and spinal cord and migrate throughout the developing CNS, and many of them ultimately differentiate into mature myelinating oligodendrocytes. Recent research has shown that OPCs and oligodendrocytes possess distinct characteristics when compared either to other types of glial cells in the CNS or to each other. Under different physiological and pathophysiological conditions, the processes of development or regeneration, the features, and, in some cases, even the functions of oligodendroglia can be modified. These changes can contribute to disease progression and affect the functional status of the nervous system. For instance, experience-dependent "adaptive" myelination plays a crucial role in the plasticity of neuronal circuits and influences learning processes; additionally, the non-myelinating functions of oligodendroglia expand their pathological potential, allowing them to regulate neuronal development and activity, angiogenesis, astrocyte maturation, and neuroinflammation. This chapter serves as a comprehensive introduction to oligodendroglia by presenting evidence from fundamental studies and fresh insights into their development, physiological and pathophysiological attributes, as well as the newly discovered non-myelinating functions.