Glia 2 Flashcards
How was the origin of microglia discovered?
Formed chimeric embryos
Transplanted tissue was populated by microglia–> allowed ID of microglia
Role of BBB?
Prevents cells from entering the brain
Which event must microglia movement into the brain occur before?
BBB formation
What are ramified/resting microglia?
Adult form found in the brain - having numerous, fine processes
What do microglia not do when resting?
Proliferate
Normal microglial state?
Resting/ramified
What are ameboid microglia?
Round and small cells - clustered, found in development
Where are ameboid microglia concentrated?
Corpus collosum
What do microglia effectively turn into when activated?
Phagocytic macrophage
How to ID resting microglia?
fine processes OX-42
How to ID activated microglia?
thick processes, vimentin, OX-42, proliferate, migrate
How to ID phagocytic microglia?
globular, vimentin, OX-42, OX-8, proliferate
What can activated microglia do in the brain?
Release factors, destroy structures in a protective manner
What activates microglia?
Presence of antigens they “dont like”
Myelin fragments, viruses, cellular debris, CNS toxins
How do activated microglia respond to a damaged neuron?
Destroy the damaged neuron
How do activated microglia destroy a damaged neuron?
Produce toxic molecules–> superoxide, nitric oxide, pro-inflammatory cytokines (TNF-alpha)
Which cells can produce cytokines that activate microglia?
Microglia, astrocytes, neurons
How does ischaemia activate microglia?
It produces molecules that activate the microglia
Possible microglial cause in neurodegenerative diseases?
Activated microglia may kill healthy cells (neurons)
Which diseases do microglia have a causative role?
Multiple sclerosis and amyotrophic lateral sclerosis
What are protoplasmic astrocytes?
Astrocytes found in gray matter (around the cell bodies of neurons)
ROle of protoplasmic astrocytes?
Maintain BBB, interstitial environment
Transport processes for K+ and glucose
What are fibrous astrocytes?
Astrocytes found in white matter (around axons or their termini
What is glial fibrillary acidic protein?
An intermediate filament
