Neurochemistry

Question 1

What are Ionotropic Receptors? (AKAligand gated ion channels)

Answer 1

Ionotropic receptors are a type of transmembrane ion channel made up of 3,4 or 5 subunits. The channel opens in response to the binding of a specific neurotransmitter extracellularly to allow ions to pass across the membrane.

Question 2

What are Metabotropic Receptors? (AKAG protein coupled receptors)

Answer 2

These receptors are made up of 7 transmembrane domains. G proteins via a series of intracellular events using 2nd messengers led to the opening of an ion channel. So it is slower.

Question 3

List the types of G proteins.

Answer 3

Gi - inhibitory
Gs - stimulatory
Gq - stimulatory

Question 4

What are the 4 neurotransmitter classes?

Answer 4

Amino acids, amines, purines, and neuropeptides.

Question 5

How is the amino acid glycine formed?

Answer 5

Glucose -> Pyruvate -> Serine -(glycine hydroxymethyltransferase)> Glycine

Question 6

How is the amino acid glutamate formed?

Answer 6

Glucose -> Pyruvate -> Acetyl CoA -> TCA cycle -> Alpha-ketoglutarate -(glutamate dehydrogenase)> Glutamate.

Question 7

How is the amino acid GABA formed?

Answer 7

Glucose -> Pyruvate -> Acetyl CoA -> TCA cycle -> Alpha-ketoglutarate -(glutamate dehydrogenase)> Glutamate -(Glutamic acid decarboxylase)> GABA

Question 8

What is Glutamate?

Answer 8

Most common excitatoryneurotransmitterin the brain
synthesised in the presynapticterminal
Glutamate uptake and recycling(glutamate-glutamine cycle) - involvesastrocytes.

Question 9

What is Excitotoxicity?

Answer 9

overactivation of glutamate receptors (NMDA) induces neuronal cell death

Question 10

What is GABA?

Answer 10

Most common inhibitoryneurotransmitter in thebrain
Synthesised in the presynapticterminal
GABA uptakeintopresynaptic terminalandastrocyte = GAT

Question 11

What are the three GABA receptors?

Answer 11

GABAA and GABAC are both ligand gated ion channels whereas GABAB is a G protein-coupled receptor.