Lecture 4 Flashcards
(20 cards)
What are the two Ach receptors?
Nicotinic and muscarinic
What are the three glutamate receptors?
NMDA, AMPA and Kainate
What kind of receptors are the glutamate receptors?
Ionotropic
What is special about the NMDA receptor?
It is a coincidence receptor, so needs glutamate and glycine to bind, then the cell to be depolarised in order for Mg2+ to unblock the pore.
Which 5-HT receptor subtype is ionotropic?
3
Which Ach receptor is ionotropic?
Nicotinic
Which GABA receptor is ionotropic?
GABAa
Auto receptors are most commonly..
metabotropic
What metabotropic receptors of Ach are excitatory?
M, M3 and M5
What signalling cascade does Ach cause when bound to M1,3 or 5?
Gq activates PLC, PIP2 into IP3 and DAG- Calcium release from ER and PKC activation. Causes smooth muscle contraction, gland secretion and neuronal excitation.
What signalling cascade does Ach on M2 and M4 cause?
Gi/o inhibits adenyl cyclase- less cAMP, less PKC. Betay subunit activates GIRK channels which causes hyperpolarisation. This causes a slower HR and neurotransmission inhibition.
What is the EPSP?
Excitatory post synaptic potential
What is an example of an excitatory ionotropic receptor?
Nicotinic Ach receptor
What channel is opened by the nicotinic receptor?
Na+ channel- depolarises membrane
What channel is opened by an inhibitory ionotropic receptor?
Cl- which hyperpolarises the membrane
What are the two actions of metabotropic receptors?
G-protein gated ion channels or 2nd messenger cascades.
Which type of synapse is mainly excitatory?
Axodendritic
Which two types of synapse are mainly inhibitory?
Axosomatic and Axoaxonic
Describe spatial summation
Multiple synapses bring excitation at different locations.
Describe temporal summation
A single synapse has multiple action potentials at high frequency
