Glia Flashcards
What are neurofilaments?
Intermediate filaments part of the cytoskeleton
Kinesin moves organelles
Away from soma
Dynein moves organelles
To the soma
Two types of macroglia of the CNS
Astrocytes, oligodendrocytes
Is there microglia in the PNS?
No
What are the PNS equivalent of astrocyte?
Satellite cells and enteric ganglia
What is the PNS oligodendrocyte equivalent?
Schwann cells
What glial cells are found in the retina?
Muller cells
What are ependymal cells?
Form neuroepithelium that lines ventricles and makes cerebrospinal fluid,
Astrocytes develop from
Radial progenitors
Mature astrocytes are known as
Stellate cells
How do astrocytes communicate?
Gap junctions
Which cells myelinate the central axons of dorsal root ganglion neurons?
Oligodendrocytes
Which cells remove excess glutamate at excitatory synapses?
Astrocytes
Which cells form the outer surface of the CNS?
Astrocytes
Cells are responsible for production of all neurons in the cerebral cortex?
Astrocytes
How is GABA transmission terminated?
Uptake of GABA by GABA transporter 2/3 (GAT 2/3) into astrocytes, where GABA transaminase (GABAT) converts it into succinic semialdehyde (SSA).
How is neuronal glutamate supplied?
Neuronal glutamate (Glu) is synthesized from glutamine (Gln) supplied by glial cells.
How is glutamate removed from synapse?
Moves back into glial cells via EAAT1/2
What do astrocytes provide to neurons? (metabolism)
Lactate
Multiple sclerosis
CNS myelin degeneration, autoimmune disorder. Leads to ataxia, fatigue, chronic pain, bowel incontinence.
Guillian Barre
PNS myelin degeneration
How neuron to oligodendrocyte ratio vs neuron to myelin ratio?
One oligodendrocyte will myelinate several neurons clumping them together
Several Schwann cells for one neuron
% of brain cells which are microglia
2.5-10%
What type of cell are microglia, where do they originate?
Macrophage, from mesoderm derived from monocytic lineage of yolk sac
Four states of microglia
Ramified (surveilling/resting): when there is no pathology, this state is assumed.
Activated (reactive): injury or assault to the brain.
Phagocytic: phagocytotic function when activated
Dystrophic: aged or mature microglia show abnormal morphology. Have more processes and swellings.
The ionic composition of the cerebrospinal fluid is maintained by
Ependymal cells
Peripheral nerve repair is stimulated by
Schwann cells
The blood brain barrier is formed by tight junctions between
Endothelial cells
Blood brain barrier
Interstitial fluid – blood
Blood – CSF barrier
CSF – blood (different barriers for ventricular CSF and blood and subdural CSF – blood)
CSF – interstitial barrier permeability
Fully permiable
What cells cover endothelia at BBB?
Pericytes
How are astrocytes associated with the blood brain barrier?
Astrocytes extend astrocytic end feet onto blood vessel forming a neurovascular unit
Around the small vessels the basal laminae of vessels and glial cell fuse, and the subpial layer of glial endfeet becomes continuous with the perivascular endfeet.
Pericytes are
Contractile cell of the blood vessel
What other action as well as contractility can pericytes have?
Phagocytosis
What cells are responsible for the induction of BBB properties in endothelial cells?
Astrocytes
What is the relative potassium concentration of CSF compared to plasma?
Lower in CSF (Na+ and chloride are higher)
