Glutamate

Question 1

Excitatory amino acid neurotransmitters

Answer 1

Aspartate & Glutamate.

Question 2

Inhibitory amino acid neurotransmitters

Answer 2

Glycine & GABA.

Question 3

Glutamate Synthesis

Answer 3

Most glutamate molecules are broken down from sugar glucose.

Question 4

Glutamine

Answer 4

precursor of glutamate.

Question 5

Glutaminase

Answer 5

enzyme that transforms glutamine into glutamate.

Question 6

Vesicular glutamate transporter (VGLUT)

Answer 6

transports glutamate from the cell cytoplasm into the vesicles.

Question 7

Glutamate can be released from cells in two ways:

Answer 7

1. ) Vesicular release:
   - Glutamate released at the synapse.
   - Biphasic: 20% burst + slow release.

2.) Reversal of uptake carriers

Question 8

Excitatory Amino Acid Transporters (EAATs)

Answer 8

take up & remove glutamate from cell membrane.

Question 9

Glutamine synthesis

Answer 9

Inactivates glutamate.

Question 10

Roles of Glutamate

Answer 10

• Precursor of GABA.
• Detoxifies ammonia.
• Synaptic plasticity
• Learning and memory.
• Neurotrophic: support the growth of developing and mature neurons.
• 50% of brain synapses.
• Protein & peptide synthesis.

Question 11

Ionotropic Glutamate Receptors

Answer 11

1. ) AMPA
2. ) Kainate
3. ) NMDA

Question 12

AMPA receptor

Answer 12

• Responsible for fastest glutamate response.
• Flow of Na+ into cell → depolarizes cell.
• Involved in motor coordination & brain excitation.

Question 13

Kainate receptor

Answer 13

• activated by binding of kainic acid (comes from seaweed & shellfish).
• Flow of Na+ into cell → depolarizes cell.
• Domoic acid in this receptor can cause excitotoxic brain damage.

Question 14

NMDA receptor

Answer 14

Allows both Na+ and Ca2+ to pass (Ca= second messenger).

Both glutamate and glycine/D-serine must bind at the same time.

Question 15

excitatory hypothesis

Answer 15

neurons are damaged and killed by the overactivation of NMDA and AMPA receptors.

Question 16

Necrosis

Answer 16

unprogrammed death of cells.

Question 17

Apoptosis

Answer 17

the death of cells which occurs as a normal part of an organism’s growth.

Question 18

NMDA Receptor Binding Sites

Answer 18

1. ) Neurotransmitter site: EAA agonists & antagonists.
   - faciliate & impair
2. ) Co-activating site: Glycine, D-serine.
   - faciliate
3. ) Polyamine site: Spermine, spermidine (increase affinity for glycine).
   - facilitate
4. ) Zinc site: Antagonist action.
   - impair
5. ) PCP site: PCP, ketamine (block channel).
   - impair
6. ) Magnesium site: blocks receptor channel, if channel becomes depolarized Mg leaves and channel opens for glutamate.
   - impair

Question 19

mGluRs 1-8

Answer 19

metabotropic glutamate receptors

Question 20

long-term potential (LTP)

Answer 20

persistent increase in synaptic strength following high-frequency stimulation of a chemical synapse.