The role of Neurones and Glia Flashcards
What is the general function of a neurone?
Sense changes and communicate with other neurones
What is the main function of an astrocyte?
Provide nutrition for neurones via the glucose-lactose shuffle
What is the general function of a oligodendrocyte?
To myelinate the neurones in the CNS
What is the general function of the microglia?
To provide an immune response by recognising foreign material
How do astrocytes remove neurotransmitters and why do they do this?
Have transporters for glutamate
Keep extracellular concentration low
How do astrocytes act to cope with high levels of brain activity?
Increase uptake of K+ ions
Which glia make up the blood brain barrier?
Astrocytes
What is the function of the blood-brain barrier?
Limit diffusion of substances from the ECF to the CSF.
Describe the layers of the blood-brain barrier
The capillaries have tight junctions between endothelial cells
A basement membrane surrounds the endothelial cells
Attached to the basement membrane are end feet of astrocyte processes
Name 3 substances which are transported across the blood brain barrier
Glucose
Amino acids
Potassium ions
Why can the brain not undergo a full inflammatory response?
The skull is a fixed structure and a large inflammatory response would create too much pressure.
Instead, the microglia act as antigen presenting cells and only then do T-cells enter the CNS
What is the most common excitatory neurotransmitter in the brain?
Glutamate
Give an example of a ionotropic glutamate receptor
AMPA
NMDA
Kainate
Which ion are NMDA receptors permeable to?
Ca2+
Describe the process of long-term potentiation
Activation of NMDA receptors upregulate AMPA receptors. Strong, high frequency stimulation causes longer signals
