10.1 2

Question 1

What are the two main amino acid neurotransmitters in the CNS?

Answer 1

L-glutamate and GABA

Question 2

Which neurotransmitter is the principal excitatory transmitter in the CNS?

Answer 2

L-glutamate

Question 3

Which neurotransmitter is the main inhibitory transmitter in the CNS?

Answer 3

GABA

Question 4

Glutamate in the CNS is mainly derived from which two sources?

Answer 4

Glucose and glutamine (from astrocytes)

Question 5

Astrocytes contribute to glutamate synthesis primarily through which molecule?

Answer 5

Glutamine

Question 6

AMPA and kainate receptors conduct which ion?

Answer 6

Na+ (sodium)

Question 7

NMDA receptors primarily conduct which ion?

Answer 7

Ca2+

Question 8

Which two molecules must bind to the NMDA receptor for activation?

Answer 8

Glutamate and glycine

Question 9

What ion blocks NMDA receptors at resting membrane potential?

Answer 9

Mg2+

Question 10

Glycine antagonists indirectly inhibit the action of which neurotransmitter?

Answer 10

Glutamate

Question 11

Ketamine acts on NMDA receptors in what way?

Answer 11

It blocks the NMDA receptor channel

Question 12

Enhanced activation of which receptor subtype is mainly responsible for excitotoxicity?

Answer 12

NMDA receptors

Question 13

Interruption of blood flow to the brain causes what initial event leading to excitotoxicity?

Answer 13

Depolarization of glutamate-releasing neurons

Question 14

What happens when ischemic neurons release excessive glutamate?

Answer 14

AMPA, NMDA, and metabotropic receptors are overstimulated

Question 15

Excessive Ca2+ entry through NMDA receptors activates which damaging enzymes?

Answer 15

Proteases (calpains) and lipases

Question 16

High levels of nitric oxide (NO) during excitotoxicity damage which types of molecules?

Answer 16

Membrane lipids, proteins, and DNA

Question 17

Domoic acid is an analogue of which neurotransmitter?

Answer 17

Glutamate

Question 18

What seafood toxin caused neurodegeneration in Newfoundland in 1987?

Answer 18

Domoic acid

Question 19

Fast neurotransmitters act through which type of receptor?

Answer 19

Ligand-gated ion channels

Question 20

Slow neurotransmitters and neuromodulators act through which receptor type?

Answer 20

G-protein-coupled receptors

Question 21

Which receptors mediate fast excitatory synaptic transmission essential for brain function?

Answer 21

AMPA and kainate receptors

Question 22

Activation of which receptor is involved in long-term changes such as learning and memory?

Answer 22

NMDA receptors

Question 23

Blocking glutamate receptors may reduce what pathological process?

Answer 23

Excitotoxicity

Question 24

What two NMDA antagonists are used clinically?

Answer 24

Ketamine and memantine

Question 25

Memantine is clinically used to treat what disorder?

Answer 25

Alzheimer's disease

Question 26

AMPA agonists may be used clinically to help treat what condition?

Answer 26

Dementia

Question 27

What happens when chloride enters a postsynaptic neuron through an inhibitory channel?

Answer 27

Hyperpolarization and reduced likelihood of action potential

Question 28

What happens when sodium enters through an excitatory cation channel?

Answer 28

Depolarization and possible action potential

Question 29

Which receptor subtype is a G-protein-coupled glutamate receptor?

Answer 29

Metabotropic (AP-4) receptors

Question 30

Under normal conditions, which receptors are activated first during synaptic transmission?

Answer 30

AMPA receptors

Question 31

During learning, increased Ca2+ entry through NMDA receptors activates which enzyme?

Answer 31

CaMKII (Calcium/calmodulin-dependent protein kinase II)

Question 32

Long-term potentiation involves increased expression of which receptor on the postsynaptic membrane?

Answer 32

AMPA receptors

Question 33

What is the effect of glutamate-induced Ca2+ accumulation on neuronal survival?

Answer 33

It promotes neurotoxicity and cell death

Question 34

Which type of receptor contributes to both learning-related plasticity and excitotoxic damage?

Answer 34

NMDA receptors

Question 35

What is the effect of excessive NMDA activation on intracellular calcium levels?

Answer 35

Dramatically increased Ca2+ concentration

Question 36

Which CNS drugs commonly interfere with chemical signaling pathways?

Answer 36

Neuroactive drugs such as alcohol, nicotine, cannabis, opiates, amphetamines

Question 37

Neurotransmitters may be excitatory or inhibitory depending on what factor?

Answer 37

The receptor subtype they bind to

Question 38

Which step-by-step diagram shows Ca2+ entering from multiple sources, activating protease, lipase enzymes; causing cell damage?

Answer 38

The excitotoxicity diagram (page 18)

Question 39

Which ions enter through AMPA receptors during depolarization?

Answer 39

Na+

Question 40

Which receptors modulate synaptic transmission through second-messenger pathways?

Answer 40

Metabotropic glutamate receptors (AP-4)