Lecture 12-Post-Synaptic Mechanisms

Question 1

What are the two types of NT receptors found on the post-synaptic membrane?

Answer 1

Iontropic (receptor is channel)

Metabotropic (uses 2nd messanger system)

Question 2

What is the advantage of using an ionotroic receptor?

Answer 2

speed- binding of NT immediately opens channel to cause depolarization

Question 3

What is the advantage of using a metabotropic receptor?

Answer 3

amplification- binding of NT cause cause many downstream effects

Question 4

Why is there no net driving force on Cl?

Answer 4

because the equilibrium potential of the membrane is very close to the equilibrium potential for cholorine

Question 5

How does the NT GABA act on synapses?

Answer 5

Inhibits activity by increasing membrane permeability to chlorine and therefore antagonize an excitatory influences and make it more difficult to depolarize the membrane

Question 6

Where is the “decision” to fire an action potential made by integrating all of the inhibitory and excitatory information that a particular neuron receives?

Answer 6

axon hillock

Question 7

What are twoways to inhibit a cell from firing?

Answer 7

increase chlorine conductance

increase K conductance

Question 8

What is the reversal potential?

Answer 8

the voltage at which there is no net movement through a channel

Question 9

What it the reversal potential for a single ion channel (i.e.. only lets Na or K through)?

Answer 9

the equilibrium potential for that ion

Question 10

What is the reversal potential for a multi-ion channel?

Answer 10

the ratio of the permeabilites determines which equilibrium potentials it will be closer to, if it is equally permeable to both then the reversal potentials would just be the average of the two equilibrium potentials