BIOL273 Chapter Notes - Chapter 3: G Protein–Coupled Receptor, Axon Terminal, Exocytosis

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scarletbuffalo29

11 Sep 2016

School

University of Waterloo

Department

Biology

Course

BIOL273

Professor

Vivian Dayeh

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Document Summary

In presynaptic neuron, action potential travels down the axon, reaches the terminal of the axon and signals the opening of ca2+ channels in the membrane, calcium enters. The entry of calcium signals the release of neurotransmitters from the vesicles (vesicles can either release them through exocytosis or with docking proteins through kiss+run method) The neurotransmitter diffuses across synaptic cleft and binds with receptors on the membrane of the post synaptic membrane of the post synaptic membrane. This opens ion channels in the post synaptic cell, depending on which ion channels are opened this results in depolarization or hyperpolarization. The bound neurotransmitter is then degraded or diffuses back to the synaptic cleft and is taken up by the presynaptic cell again. If they open, more na+ can come in epsp depolarization or more k+ can go out ipsp hyperpolarization. If they close, na+ can"t come in ipsp hyperpolarization, or k+ can"t go out epsp depolarization.

Related Questions

From the following list, select all options that are correctwith respect to the synapse.

Question 5 options:

A)	the synapse is the site where the plasma membrane that coversthe axon terminal of one neuron makes direct contact with and fusesto the plasma membrane on the cell body or dendrite of anotherneuron

B)	the action potential travels through extracellular fluid in thesynapse to get from one neuron to the next

C)	presynaptic nerve terminals release chemical messengers into thesynapse in response to arrival of an action potential

D)	signaling molecules in the synapse can be broken down by enzymesthat are present on the post synaptic cell membrane

E)	signaling molecules in the synapse can bind to 're-uptake'receptors and be taken back into the presynaptic neuron forbreakdown or for repackaging/reuse

F)	signaling molecules can be taken into and degraded within thepostsynaptic cell

G)	signaling molecules in the synapse function as chemicalmessengers that regulate the opening of ligand-gated channels inthe plasma membranes of post synaptic cells

graymink444

Which one of the following is an experimental evidence that demonstrates the reverse-transport model of amphetamine action? At high concentration of amphetamine,

a. it shows saturation kinetics when all the transporters are occupied and reversed.

b. it requires Ca++ ions entry to release neuotransmitters.

c. it requires action potential firings at the pre-synaptic terminal

. d. it is broken down by the COMT enzyme at the synapse, rendering it useless.

e. it is synthesized by the presynaptic neuron

33. When the reuptake of dopamine is blocked by the Ritalinâ¢ or cocaine molecule, what would happen?

a. increase in dopamine synthesis by the presynaptic neuron

b. decrease in dopamine synthesis by the presynaptic neuron

c. dopamine level at the synaptic cleft would be prolonged

d. dopamine level at the synaptic cleft would be decreased

e. enhance the release of dopamine from the presynaptic terminal.

Which experiment is used to prove that release of dopamine induced by amphetamine is not coming from vesicular release? a. dopamine is released by activation of action potentials in the presynaptic neuron without amphetamine. b. dopamine release only in the presence of magnesium. c. dopamine release is dependent on depolarization of post-synaptic cell. d. dopamine release from axon terminal can occur in Ca++ free medium. e. dopamine release is quantal in amount.

Why do ion channels not function like open pores?

What is membrane potential?

How do K⁺ leak channels work? Why is the membrane potential of a resting cell negative?

What is patch clamp recording? What is one of the major insights gained from patch clamp reporting experiments?

Compare and contrast the three types of gated ion channels.

Be familiar with the different parts of a neuron.

During an action potential, what happens to the membrane potential, voltage-gated Na⁺ channels, Na⁺ ions, voltage gated K⁺ channels, K⁺ ions, and Na⁺-K⁺ ion pumps?

When an action potential reaches a synapse, what happens to the Ca²⁺ channels, Ca²⁺ ions, neurotransmitters, transmitter-gated ion channels, and the post synaptic neuron?

What effect do excitatory or inhibitory neurotransmitters have on postsynaptic cells?

What is an example of a mechanically gated ion channel?

BIOL273 Chapter Notes - Chapter 3: G Protein–Coupled Receptor, Axon Terminal, Exocytosis

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