L11- Plasticity of Neuron-Glia interactions Flashcards
Where do oligodendrocytes originate from?
Neuroectoderm
What do oligodendrocytes do?
Myelinate several axons
Where do Astrocytes orginate from?
Neuroectoderm
What do astrocytes do?
Enwrap axo-dendrtici synapses
Regulate function at the BBB
Regulate vasodilation
Regulatory function at the synaptic compartment
Regulatory function at the nodes of ranvier
Where do microglia originate from?
Mesoderm/mesenchymal origin
What do microglia do?
Surveillane function
Neuroprotectors through phagocytosis
Antigen presenters like macrophages
Sense synaptic activity
What do the endfeet of astrocytes do at the blood brain barrier?
Regulate what enters/leaves the brian parenchyma
Regulate vasodilation
What do Aquaporin 4s do at the BBB?
Regulate astrocyte migration and potassium uptake during neuronal transmission
What are the symptoms of major depressive disorder?
Anhedonia, Cognitive impairment, Memory deficits
What happens to BDNF in MDD?
There is a decrease in LTp using glutamate meaning there is no re-uptake meaning that BDNF release is decreased and GABA release is increased from the glia
What could disrupt the cross-talk between the neuron and glia?
Changes in glia cell number of glial cell size
What would a disruption in cross talk between astrocytes and vasculature cause?
A decrease in coverage of blood vessels
In MDD patients and HAB rats what is reduced?
The coverage of blood vessels by aquaporin 4 and astrocyte end feet
If you add Fluxetine to a HAB rat IPS cell what happens?
It can rescue the astrocyte processes however not the Aquaporin 4 channels at the endfeet.
What are the symptoms of Schizophrenia?
Hallucinations
Disordered thoughts
Psychosis
What is NRG1 used for?
the NRG1 gene is used for axonal guidance, oligodendrocytes, synaptic transmission, radial glia and the NMJ
List some anti-convulsant actions
Potassium uptake Glutatmate uptake Water extrusion into the blood Dlutamate conversion to glutamine ATP release converted to adenosine Anti-inflammatory cytokines Gap-junction complexes Neurosteroids
List some pro-convulsant actions
Glutamate and D-serine release ATP release Cell swelling Pro-inflammatory cytokines Adenosine metabolism TGFpR pathway activation by albumin
How do astrocytes and microglia help prevent epilepsy?
Pruning
List some common symptoms of Alzheimer’s Disease
Increased memory loss
confusion
Inability to learn new things
Difficulty carrying out multi-step tasks
Outline the Alzheimer’s study on transgenic mice
WT mice had normal astrocytes and a normal working memory
5xFAD mice had reactive astrocytes which were larger and produced more GABA this created an LTP deficit leading to working memory impairment
What are the two types of neuron-glia communication types?
Gliotransmitters (non-contact dependent)
Membrane bound factors (contact dependent)
List some gliotransmitters
Glutamate ATP TNFalpha Adenosine D-serine
Give 2 examples of membrane bound neuron-glia communication factors
Ephrin A3/ EphA4
Cx3c11/Cx3cr11
How can in vitro cultures be used to examine glia?
By growing astrocytes then applying various substances to them
How can fixed tissues be used to examine glia?
Using staining to evaluate morphological changes
How can in-vivo experiments be used to examine glia?
Evaluate morphological changes
Flourescence microscopy
transgenics to determine the role of glia
