Glycine Receptors Flashcards
what type of selectivity do transmitter-gated Gly receptors exhibit (anion/cation)?
- anion selectivity
where are Gly Receptors expressed (hint: CNS)
- spinal cord
- brain stem
- cerebellum
- dorsal raphe
Glycine neurotransmitter and its relation to glutamate (think: what receptors does glutamate activate)?
- acts as D co-activator and hence:
- activates excitatory NMDAr´s
What functions do Gly receptors regulate?
- respiratory rhythm
- motor control
- muscle tone
- sensory/pain processing
most frequent mutations in GlyR alpha1 R271 (what residues)?
- what is the effect of mutations (hint: loss of function) ?
- R271Q
- R271L
- decreases GlyR sensitivity to glycine
- decreases single channel conductance
what are the similarities between GABAa and Glycine receptor?
- both cys-loop
- Cl- conducting
- transmitter-gated
- both found in motor neuron
how would you describe GABA-ergic mIPSC´s in comparison to Glycine mIPSCs?
GABA-ergic miniature inhibitory postsynaptic currents are prolonged—
what subunits/stoichiometry can glycine receptors exist in?
subunits a1-4, b1
- exist as pentamers (a1,5 and a1,2-b3)
what is strychnine and where is it obtained from?
- what are it´s effects?
- from poisonous nuts of tree
- potent competitive antagonist
enhances pain perception/causes convulsion
GlyR mutations can lead to hyperplexia (human startle disease)
what are the results of these mutations?
what part of the body do these mutations effect?
- disruption of Glycinergic synapses in neuromotor pathways
- occuring in spinal cord, brainstem
what components of glycinergic transmission (i.e. subunits) are associated with hyperekplexia mutations?
glycine a1 subunit
- b subunit to lesser extent
- GlyT2 (neuronal glycine) transporter
effects of hyperekplexia?
- neonatal hypertonia
- exaggerated startle response
How can hyperekplexia be treated?
- clonazepam ( benzodiazepine aka
( GABAa receptor PAM )
