Neurobio Test2: Recitation 6 Flashcards
What is SEP
pH sensitive dye
How is SEP used in the study?
N-terminus of glutamate receptors are tagged. If they move from low pH of endosomes, to neutral pH of neuron surface, dye lights up
How do authors mimic LTP?
Electrode stimulation of CA1 mimicking epilepsy
What is APV
Drug that blocks NMDA receptors
What is APV used to demonstrate
Enlargement of dendritic spines no longer induced with APV during LTP-level stimulation. NMDARs must be needed for enlargement
Increase in receptors due to lateral migration of endocytosis? How do you know?
No significant change in number dendritic receptors before and after LTP - must be exocytosis
Order of events: more AMPA receptors at spine, enlargement of spine
Spine enlarges first
Is volume change of spines proportional to initial size?
No. End up at same volume.
Presynaptic: CA3 or CA1
CA3
CNQX
antagonist of AMPA
How do we know receptors dont just diffuse and follow changes in surface area?
different subunits have different response to LTP
How do we know fluorescence of pH-sensitive dye was not due to localization caused by fluoruophore?
Greater fluorescence was observed on edges of dendrites compared to center.
Authors developed new method of inducing LTP involving bath application because
They needed to reliably stimulate a large number of neurons terminating at the synapses in their field of view
How was the LTP protocol (chemLTP) developed for the study different than a seizure protocol?
- removal of bath prevented spontaneous bursts
- fully sensitive to APV
- No spine loss or dendritic death
- chemLTP drives GluR1 into synapses
The fact that the spine enlarges before AMPA accumulates demonstrates:
existence of multiple distinct mechanisms during LTP