Glia Flashcards
Glia are also called ??? and are specialised cells found in close association with neurons.
neuroglia
TRUE or FALSE: There are ~10 times more glia than neurons.
TRUE
Glia support neuronal function. They provide neurons with ??? support and maintain appropriate microenvironment essential for neuronal function.
structural
Glia are critical for neuronal signalling through roles in ???, neurotransmitter balance, potassium (K+) buffering etc
myelination
??? (glia type) can be found in both white and grey matter
astrocytes
what is the most abundant type of glia?
astrocytes
Astrocytes play crucial roles in neurodevelopment and in maintaining the cellular environment to avoid disruptions to neuronal ???
signalling
Astrocytes remove potassium from the ??? fluid to ensure appropriate concentration of K+ is maintained on the inside vs outside of cell
extracellular fluid (ECF)
inwardly rectifying potassium channels 4.1 (Kir4.1 channels) on ??? membranes take K+ from the ECF and internalise it
astrocyte
astrocytes are connected to each other by ??? junctions
gap junctions
Kir4.1 (potassium channel) is enriched at astrocytic endfeet where it co-localizes with ??? cannels. These channels facilitate bidirectional water flow in all cells and tissues and is highly expressed in astrocytes.
aquaporin 4
??? channels have been implicated as a key determinant of glymphatic function. The glymphatic system is a brain-wide network of perivascular pathways along which CSF enters the brain and interstitial solutes are cleared.
aquaporin 4 (AQP4)
Glymphatic exchange is driven by ??? pulsation, active primarily during sleep, contributes to the clearance of interstitial amyloid-β, tau, and other solutes such as lactate, and inflammatory cytokines.
arterial
Astrocytes sit very close to glutamatergic and GABAergic synapses (i.e. they are perisynaptically located) and have glutamate and GABA transporters on their membranes. They clear glutamate and GABA from the ???using these transporters and metabolise them
synaptic cleft
Through a process called reactive ???, astrocytes respond to varying amounts of brain injury
astrogliosis
scar-forming ??? occurs at the lesion site to isolate tissue damage. Astrocytes upregulate glial fibrillary acidic protein (GFAP), hypertrophy, proliferate, overlap their cellular processes to form a dense astrocytic border that encloses a lesion core of non-neural cells.
astrogliosis
TRUE or FALSE: Endothelial cells of capillaries only form tight junctions in the presence of astrocytes
TRUE
radial glia is a type of ??? that acts as a “highway” to help guide newborn neurons to their correct location in the cerebral cortex
astrocyte
In the CNS, the myelin forming glia are oligodendrocytes. In the PNS, the myelin forming glia are ??? cells.
Schwann
Oligodendrocytes are derived from the neuro-ectoderm. Schwann cells are derived from the ???
neural crest
Oligodendrocytes are primarily located in WHITE or GREY matter?
white matter
When nerves are injured in the PNS, SCHWANN CELLS or OLIGODENDROCYTES actively secrete molecules which promote axon growth and therefore nerve repair?
Schwann cells
In the CNS in response to nerve/ axon injury, SCHWANN CELLS or OLIGODENDROCYTES release molecules that inhibit axon growth/repair.
oligodendrocytes
In Multiple Sclerosis, antibodies are produced which attack and lead to the death of ??? and subsequent axonal dysfunction
oligodendrocytes
