glia cells

cns glia and pns glia

ependymal cells, oligodendrocytes, microglia, astrocytes

schwann cells, satellite

what are ependymal cells

they line the ventricles, produce CSF, source of neural stem cells

what are oligodendrocytes

myelinate up to 50 axons per cell

microglia

resident immune cells of CNS, phagocytose debris, prune synapses and whole cells, secrete helpful and harmful factors

astrocytes

form the bbb, make brain scaffold, provide metabolic support for neurons, help reuptake and release NT and ions

what are schwann cells

wrap about axons to myeline s

what are satellite cells

cover ganglia to provide support and maintain ion balance of extracellular space similar to astrocytes

what is the tripartite synapse

ensheathed by astrocytic processes at varying degrees based on location and environmental factors, uptake of glutamate through EAATs and recylcing of glutamate to glutamine with glutamine synthetase, changes shape and moves, awake astrocytes move toward synapses, during rest they retract

protoplasmic astrocytes

gray matter, long processes with bushy branches, endfeet make up bbb, communicate with neurons at tripartite synapse, involved in elimination and formation of synapses

fibrous astrocytes

made up of mostly white matter

astrocytes and synapse formation

axons extent to targets within days, but no synapse form until the differentiation and maturation of astrocytes = release thromobospondins, astrocytes = increase synaptic structures, increased postsynaptic activity = induces ampa receptor lcoalization to post synaptic density, enhanced nt release

astrocytes role in synapse elimination

associated with synapses in every way, close control over synaptic trans,ission and formation and elimination, nervous system creates more synapses than it needs, but weak pruned away, strong mature, synaptic plasticity = elimination of synapses which is mediated by astrocytes

astrocytes and uptake

are responsible for the majority of glutamate uptake, glutamate takes up, 3 na+ and 1 h+ also taken up, k+ pushed out

astrocytes and neural signaling

astrocytes have membrane potentials, metabotropic and ionotropic receptors, voltage and ligand gated ion channels, sodium / potassium pump, glutamate, ach, nore, atp etc. receptors, gliotransmitters from synaptic like microvesicles = atp, glutamate, d-serine and gaba

how are astrocytes connected

gap junction channels, not uniform, as groups of em = network, calcium waves travel

commuincation between otehr glia

neuron opc synapse - oligodendorcyte precursor cells, microglia and neurons