psychostimulants

Question 1

what are the ionotropic glutamate receptors

Answer 1

AMPA, kainate & NMDA

Question 2

what does the Q/R site determine on an AMPA receptor

Answer 2

determines Ca2+ permeability of GluA2

Question 3

what is a tetramer

Answer 3

four AMPA receptors GluaA1-4 subunits in any combination

Question 4

why do AMPA receptor containing GluA2 have a low CA2+ permeability

Answer 4

due to mRNA editing -> +charged arginine (R) residue expressed instead of neutral glutamine (Q) in pore forming M2 region of GluA2

Question 5

what are mechanisms of LTP

Answer 5

increased neurotransmitter release, increased receptor number, increased conductance

Question 6

what are the 3 important properties of NMDA receptors

Answer 6

• high Ca2+ permeability
• Mg2+ ions block channek at negative (i.e.resting) membrane potentials
• glycine is a necessary co-agonist (in addition t glutamate)

Question 7

why is NMDAR coincidence detector

Answer 7

• activation of AMPAR depolarises the membrane to remove Mg2+ block of NMDAR
• this allows Ca2+ entry through NMDAR and it depends on pre&postsynaptic elements being active at the same time

Question 8

what is long term potentiation (LTP)

Answer 8

long lasting potentiation of synaptic transmission

Question 9

what is long term depression (LTD)

Answer 9

long lasting of synaptic transmission depression

Question 10

what are some pathophysiological roles of NMDA receptors

Answer 10

excitotoxcity (neuronal cell death from too much Ca2+ entry), epilepsy, schizophrenia, transmission of pain responses