Synaptic plasticity

Question 1

NMDA-Dependent Long Term Potentiation (LTP)

Answer 1

a long-lasting enhancement in the effectiveness of synaptic transmission, neurons that fire together wire together

Question 2

NMDA-Dependent Long Term Depression (LTD)

Answer 2

a long-lasting decrease in the effectiveness of synaptic transmission, neurons out of sync lose their link

Question 3

Relationship between AMPA and NMDA receptors

Answer 3

they coexist at glutamatergic synapses

Question 4

properties of AMPA receptors

Answer 4

permeable to Na+ and K+, opens in response to glutamate binding, primarily responsible for EPSPs

Question 5

properties of NMDA receptors

Answer 5

permeable to Na+, K+ and Ca+, ligand (glutamate) and voltage (depolarization) dependent activation, Mg2+ blocks channel at rest but moves during depolarization , summation is important for their opening (could be temporal or spatial)

Question 6

mechanism of LTP

Answer 6

Lots of Ca2+ flows into neuron (HFS), Initiates potentiation: promotes kinase activity, phosphorylates AMPA receptors which cues them to be inserted into the membrane thereby increasing the number of receptors and EPSPs, Sustains potentiation: activates transcription factor called CREB which leads to synthesis of more AMPA receptors

Question 7

mechanism of LTD

Answer 7

Small amount of Ca2+ flows into cell (LFS), activates protein phosphatases which unphosphorolate synaptic protein to yield LTD