Synaptic refinement Flashcards Preview

Building the nervous system > Synaptic refinement > Flashcards

Flashcards in Synaptic refinement Deck (8)
Loading flashcards...
1

What is Donald Hebb's rule of plasticity

Co-ordinated activity of a presynaptic terminal and a post synaptic neuron strengthen the synaptic connections between them
Neurons that fire together wire together

2

What is the postsynaptic response resulting from increasing stimuli

With increasing stimulus comes more afferents - increase postsynaptic potential at a steady rate - quantal increase

3

How do climbing fibres change in the developing cerebellum

Initially 4 climbing fibres per purkinje cell - 1 to1 in mature
Climbing fibres also reorganise - initially synapse with the soma - mature with dendrites - Post synaptic response recorded in mature soma has varied time response due to different distances of dendrites away from the soma

4

How was ocular dominance used to show connection focusing

Cortical layer 4 presents ocular dominance bands - where input to an individual neuron is from a single eye
One eye is blocked - near complete loss of functional connectivity from the deprived eye to the visual cortex

5

What was the result of both eyes being closed on ocular dominance

Had very little effect on the ocular dominance of cells in the visual cortex - proves that it is not caused by visual deprivation but by an imbalance in activity between both eyes

6

What is the role of the CA1 region of the hippocampus and what neurons come into it

Memory formation - Schaffer collaterals come up into this area - strength of the synapse varied according to synaptic activity

7

What does tetanic stimulation cause

Increases the postsynaptic response but stays enhanced for months/years - long term potentiation

8

What is the mechanism of LTP

tetanic stimulation causes the voltage dependent Mg block of the NMDA receptor to be removed - causes a calcium influx at the postsynaptic terminal - this causes an increase in AMPA receptors becoming available at the postsynaptic membrane - AMPA receptors are much more responsive to glutamate.