6: Synaptic transmission pt2 Flashcards
What are the three main types of neurotransmitter
- Acetylcholine
- Glutamate
- GABA
What are two main classes of receptor
- Ligand-gated ion channels (ionotropic receptors) “stimulus gated”
- G- protein coupled receptors (metabotropic receptors)
What type of channel does an acetylcholine receptor have
Ligand -activated ion channels
What type of potential does acetylcholine receptors generate
Excitatory post synaptic potentials -EPSPs
How many subunits does acetylcholine receptors have?
5 subunits (pentamer)
How many transmembrane domains does acetylcholine have?
4 transmembrain domains
What ions are actylcholine receptors permeable to?
Na2+ and Ca2+
What energy output does acetylcholine have?
Depolarises
Give some examples of drugs that Acetylcholine are blocked by
- Bungarotoxin (snake toxin)
- TTX
- Curare (a plant toxin)
What type of channel does glutamate have?
-Ligand gated ion channels
What type of potential does glutamate generate?
Excitatory (EPSP)
How many subunits are in a glutamate receptor have?
Tetramer (4)
How many transmembrane domains does glutamate have?
Three transmembrane domains
What ions are glutamate permeable to?
There are three types of glutamate receptors, each permeable to different ions
- Kainate -Na+
- AMPA -Na+, K+
- NMHA -Na+, K+, Ca2+
What energy output does glutamate have?
Depolarises
Give some examples of drugs that block glutamate receptors
- Mg2 blocks NMDA receptor
- PCP “stardust” also blocks NMDA receptor
What type of channel does GABA-A have
Ligand gated ion channels
What type of potential does GABA-A have?
Inhibitory _IPSPs
How many subunits does GABA-A have?
Pentamer (5 subunits)
How many transmembrane domains does GABA-A have?
four transmembrane domains
What ion is GABA-A permeable t?
Cl-
What energy output does GABA-A have?
Hyperpolarises
Give an example of a drug/toxin which blocks the GABA-A receptor?
Picrotoxin (plant toxin)
