Neurotransmitters and Signaling
How oligodendrocytes and OPCs receive and respond to signals: glutamate, GABA, ATP, NMDA, and beyond.
Neurons form genuine synapses onto OPCs with quantal glutamate release. Establishes direct synaptic signalling onto a non-neuronal cell.
AMPA and kainate receptor activation on OPCs slows their proliferation and shifts them toward differentiation, tying myelination to axon activity.
Interneurons synapse directly onto OPCs and release GABA onto functional GABA-A receptors, so inhibitory circuits also address the myelin lineage.
Mature oligodendrocytes carry functional NMDA receptors. In ischaemia these open and admit calcium, killing the cell and the sheath with it.
Calcium rises inside the myelin sheath itself during ischaemia, through NMDA receptors in the myelin membrane rather than in the soma.
Sustained ATP acting at P2X7 is toxic to oligodendrocytes, and blocking the receptor reduces damage in an MS model.
The amount of NRG1 type III displayed on the axon surface decides whether that axon is ensheathed and how thickly.
Kir4.1 null mice show hypomyelination and vacuolated sheaths, making potassium buffering a requirement for normal myelination.
Cx47 is the main oligodendrocyte gap junction protein; losing it vacuolates myelin, showing the glial syncytium is load-bearing.
Blocking axonal firing suppresses myelination and stimulating it promotes myelination, the original demonstration of activity-dependent myelination.
NG2 and PDGFR alpha mark the same cells, which is the marker pair still used to identify OPCs.
How the node, paranode and juxtaparanode are built and held in register, including the clustering of Nav channels at the node.
Review integrating the oligodendrocyte-specific MCT relay into a broader astrocyte-neuron lactate shuttle model; covers concentration-dependent effects and epigenetic consequences of lactate in CNS disease.
Human hippocampal tissue and THY-Tau22 mice. ENT1 inhibition disrupts oligodendrocyte lipid metabolism; myelinating oligodendrocytes are proposed as a metabolically vulnerable hub linking adenosine signaling to network disconnection in tauopathy.