7 - LGIC Flashcards
What are the two excitatory LGIC
nAChR
5-HT3R
What are two inhibitory LGIC
GABAAR
Strychnine-sensitive glycine receptors
What are two excitatory ionotropic glutamate receptors
AMPA
Kainate
NMDA
What confers ion selectivity of LGICs
M2 pore lining helices
What keeps LGICs in a closed conformation
a helices bent towards centre of pore leading to a narrow region too narrow and hydrophobic to allow ion passage
How does the LGIC pore open
Via rotation or tilting of the pore lining helices
What does bicuculline do
Competitive antagonist of most GABAAR
What do benzodiazepines do
Enhance actions of GABA
What do barbituates do
Act alone or enhance actions of GABA
What are BZ selective for GABAAR
a1, a2, a3, a5 and Y
What do PB act on
GABAAR
What is crucial to BZ binding
Histidine which is not present in a4 and a6
What do benzodiazepines cause (3)
Sedation
Muscle relaxation
Anxiolysis
What subunit mediates sedative action
a1
What subunit mediates anxiolysis action
a2
What subunits mediate muscle relaxation
a2 and a3
What subunits mediate impaired motor coordination
a1 and a3
What is the MOA of ethanol
Enhance actions of GABA
Prolongs the open time of the channel
Bind within the transmembrane domain
What is the MOA of GA
Enhance the actions of GABA
Directly stimulate receptors at high concentration
Bind at the interface between a and b subunits within the transmembrane region of the channel
What is the MOA of neurosteroids
Promote channel opening
Receptors containing y subunit are most sensitive
Glycine and strychnine bind at the subunit interface true or false
True
Where does ivermectin bind
Within the membrane of glyR
Where does picrotoxin bind
Within pore of the channel
Which GlyR has lower affinity for picrotoxins
Heteromeric GlyR
