Excitatory and inhibitory neurotransmission Flashcards
What is a typical membrane resting potential in a neuron?
-70mV
Which 4 ions are important for neurotransmission?
Na
K
Ca
Cl
Three ions flow into the cell, which are they and what are their effects on membrane potential?
Na- Flows into cell, depolarisation, excitatory
Ca- Flows into cell, depolarisation, Excitatory
Cl- Flows into cell, hyperpolarisation, Inhibitory
Which ion flows out of the cell, and what is it’s effect on membrane potential?
K- Hyperpolarisation, Inhibitory
Describe the method of action of lidocaine
Na channel antagonist
Prevents entry of sodium and therefore prevents depolarisation
Inhibitory effect on neurones
Describe how exocytosis of neurotransmitters occurs
Action potential depolarises axon terminal
Voltage gated Ca channels open and Ca enters cell
Ca entry triggers exocytosis of vesicle content
How does an ionotropic receptor work?
Receptor is a channel which opens when ligand binds
How does a metabotropic receptor work?
It is a signalling structure, the receptor binds the neurotransmitter which send signalling molecules to open associated channels
What are the two major families of ligand-gated channels?
- GABAa, glycine and ACh
- Glutamate
What do non NMDA receptors bind, and which ion gates do they control?
Kainate or AMPA
Na and K channels
What channels do NMDA receptors control?
Na, Ca, K
What is the main inhibitory neurotransmitter in the CNS
GABA
