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PSYCH 2410 (Midterm II) > Glutamate > Flashcards

Flashcards in Glutamate Deck (14)
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1
Q

Glutamate

A
  • Found everywhere in brain
  • Not localized (synthesized everywhere)
  • Excitatory amino acid neurotransmitter
  • Binds to receptor, opens NA channels, causes depolarization
2
Q

Glutamate Synthesis Cycle:

A

• Astrocyte removes glutamate from synapse and breaks it down
• Glutamine is converted to glutamate via glutaminase
• Glutaate packaged into vesicles containing VGLUT
o Vesicular Glutamate Transporter
• VGLUT load vesicles with neurotransmitter
• Too much glutamate kills neurons (occurs in stroke)
• EAAT (Excitatory amino acid transporter) removes any excitatory amino acid (not just glutamate)

3
Q

Glutamate Receptors:

A

NMDA
AMPA
Metabotropic glutamate receptor
Kainate receptor

4
Q

NMDA Receptor

A

o Important for formation of memories
o Transports Ca when activated (Ca can act as second messenger)
o Acts as both ionotropic and metabotropic receptors
o Conducts both Na and Ca
o Made of 4 subunits with various binding sites
o Opens when pre and post synaptic neurons are firing together (coincidence detector- helps wire cells together)

5
Q

AMPA Receptor

A

Inotropic

6
Q

Metabotropic Glutamate Receptor

A

o Sends second messengers, can cause negative feedback

7
Q

Kainite Receptor

A

o Ionotropic

8
Q

NMDA Binding Sites

A

Glutamate
Glycine
PCP
Magnesium

9
Q

PCP Binding Site

A

o Binding site is within channel
o Inhibitory effects
o Blocks channel, but doesn’t compete with glutamate

10
Q

Magnesium Binding Site

A

o Blocks channel, when bound, Ca and Na can’t go through

o Mg binds at -70 mV removed at -65 mV

11
Q

NMDA Receptor Subtypes:

A
  • NR1, NR2A, NR2B
  • All NMDA have 2 NR1 subtypes, but can vary by whether they have NR2A or NR2B subtypes
  • NR2B receptors are more sensitive, causes more Ca to enter cell
12
Q

Long Term Potentiation

A
  • Can be produced by experiences that result in learning

* NMDA dependent

13
Q

CA1 Knockout

A
  • Disrupted circuit to disrupt hippocampus dependent memory storage
  • Determined that NR1 subunit in CA1 is needed to produce LTP (electrode stimulation) and for Place Learning (water maze test)
14
Q

NR2B Overexpression:

A
  • Enhanced LTP, spatial learning

* Acquired memory more quickly, are better learners