Neurotransmission Flashcards
What is the most common neurotransmitter in the CNS?
Glutamate
What type of neurotransmitter is glutamate?
Excitatory
What are the types of glutamate receptors?
Ionotropic glutamate receptors
- AMPA receptors
- NMDA receptors
Metabotropic glutamate receptors
What type of receptor are AMDA and NMDA receptors?
Both of them are ion channels
Which ions do AMPA receptors conduct?
Sodium ions
Potassium ions
Which ions do NMDA receptors conduct?
Sodium ions
Potassium ions
Calcium ions
What is the function of AMPA receptors in glutamatergic synapses?
Initial fast depolarisation of post-synaptic membrane
This allows NMDA receptors to open, as they need the membrane to be depolarised first
What is the function of NMDA receptors in glutamatergic synapses?
Longer-term depolarisation
How do glutamatergic synapses contribute to learning and memory?
Long-term potentiation
What is long-term potentiation?
Activation of NMDA receptors and calcium ion influx through them
Activation of metabotropic receptors
Both cause up-regulation of AMPA receptors
Gives more frequent and stronger depolarisation of post-synaptic membrane
What is excitotoxicity?
Refers to how excessive stimulation by glutamate damages and kills neurones
What happens in excitotoxcitiy?
Glutamate activates NMDA receptors
Gives calcium ion influx
High intracellular calcium ion concentrations are toxic to cells
What are two other amino acid neurotransmitters apart from glutamate?
GABA
Glycine
What type of neurotransmitter is GABA?
Inhibitory
Where are most GABA-ergic synapses located?
Brain
