Neurotransmitters Flashcards
What are the main categories of neurotransmitters? List examples.
- Biogenic amines. Ex. acetylcholine and monoamines. Smaller than neuropeptides.
- Neuropeptides. Ex. oxytocin. Bigger, multiple AA linked together by peptide bonds.
What criteria are used for ID a neurotransmitter?
- Neurotransmitter present in presynaptic terminal
- NT is released upon action potential.
- NT receptors activated.
- Application of transmitter, agonists, or antagonists
Describe the metabolic and cellular pools of brain glutamate.
Glutamate shuttle with the astrocyte.
Define ionotropic and metabotrobic.
- Ionotropic are fast ligand gated ion channels
- Metabotropic are slow G-protein coupled receptors
What are the subtypes of glutamate receptors?
- Na+ channels (AMPA, NMDA,Kainate)
- 2nd messenger linked receptor: Quisqualate B
What are the key features of the NMDA receptor?
In addition to being a sodium channel, it is also a calcium and glycine channel. Involved in memory.
How are the glutamate receptors involved in ischemic cell damage?
In absence of oxygen/energy as in stroke, neurons will release their glutamate stores. Glutamate binds to glutamate receptors on cells, resulting in a massive influx of calcium. This leads to cell death as well as a large influx of water due to the osmotic gradient..Brain edema. Brain trauma and stroke leads to brain edema thru this pathway.
Name some excitatory and inhibitory neurotransmitters. How does their mechanism of action vary?
Excitatory: glutamate. Inhibitory: GABA, glycine
Inhibitory usually act via metabotropic receptors whereas excitatory act via ionotropic receptors.
How is the neurotransmitter glutamate inactivated?
Astrocyte pulls it out of synaptic cleft.
What neurodegenerative disorders involve glutamate receptor activation?
?
What is a major inhibitory neurotransmitter in brain?
GABA
