Neurotransmission Flashcards
What do astrocytes do?
Physiology and pathology
- Release and take up NT’s
- Express receptors (e.g NMDA)
- Regulate synaptic transmission
- produce neurotrophins
- conduct events by gap junctions
- form scars
- immune activation
Protoplasmic astrocytes
where re they found?
GFAP processes
Domain organisation -> consequence
- Most common
- Reside in layers 2-6
- GFAP positive processes do not overlap
- Cover 10 cell bodies, many synapses, 5 blood vessels; regulate blood flow in response to increased synaptic transmission
Fibrous astrocytes
location
processes
role
White and gray matter
Processes intermingle (no domain structure)
Support role and respond to injury
Gliotransmission and Glioneural functional units
The process of release of NT’s by astrocytes and the effect on neurons.
e.g adenosine to make sleep
Greatly enlarged by astrocytes in typical brain function
Microglia
Role
They are the surveyors of the brain environ, resident macrophages.
Thus mediate the brains immune response.
Also help sculpt brain during development and may modulate synaptic transmission.
Brain endothelial cells and pericytes
Both these maintain the BBB
Compromise of these in alzhemiers and stroke.
Neuromodulator
Produce a slower pre and post synaptic respone, released by nerve cells and astrocytes (e.g adenosine)
Neurotrophic factors
Act on what
Released by non neuronal cells (astrocytes, microglia) and neurons and work over long time scales.
Act on tyrosine kinase receptors to mediate growth, morphology, functional properties and survival promoting affects (e,g nerve growth factor, BDNF)
Neurotransmitter types of acting
btw neuropeptides and neuromodulators and neurotrophic factors
Fast acting: act on ion channels (GABA (Cl-), glutamate)
Slow: On G proteins e.g dopamine, neuropeptides)
depends on sub type
