Thursday, May 9, 2024

Synaptic Transmission Guiding Questions

 Synaptic Transmission Guiding Questions


Describe the sequence of events that occurs when glutamate is released from the presynaptic cell. How do these events lead to LTP?

Describe the structure of the synapse of the neuromuscular junction.

What is the neurotransmitter released from a somatic motor neuron?

What is the receptor on the muscle cell? Does triggering this receptor with neurotransmitter trigger a fast response or a slow response?

Describe the sequence of events that occurs when an action potential reaches the axon terminal of a somatic motor neuron.

How is synaptic transmission terminated at a neuromuscular junction?

What is AChE and what does it do at the synaptic cleft?

What is an agonist and how does it affect synaptic transmission? Give examples of both direct and indirect agonists.

What is an antagonist and how does it affect synaptic transmission? Give examples of both direct and indirect antagonist

Explain how GABA work to inhibit post-synaptic cell response.

How would blocking GABA receptors affect response in the post-synaptic cell?

Hint, remember our in-class handout!

Make a list of all of the ion channels we have discussed. Make sure you indicate where you find the channel, how it is gated, which way ions will travel through it and their effect on membrane potential and when it is used.

Make a list of all of the neurotransmitter-receptor pairs we have discussed. Make sure you indicate where the neurotransmitters are used and how they are regulated

Hint, we did a lot of this in our in-class handouts!

 


Peripheral Nervous System Guiding Questions

Describe the organization of the nervous system.

Be sure to use the following terms: efferent neurons, afferent neurons, sensory receptors, autonomic neurons, somatic motor neurons, parasympathetic neurons, sympathetic neurons, somatic motor neurons, skeletal muscles, central nervous system, peripheral nervous system.

What does the somatic motor division of the efferent nervous system control?

Describe the structure, target, neurotransmitter and receptor and enzyme used in the somatic motor division.

What are the two divisions of the autonomic nervous system?

What are the targets of the autonomic nervous system?

How are pre and postganglionic neurons similar and different in the sympathetic vs parasympathetic divisions?

Describe how the two divisions of the autonomic nervous system maintain homeostasis through antagonistic control.

Give several examples of antagonistic control carried out by the autonomic nervous system.

Describe how the preganglionic neuron and the postganglionic neurons are arranged in the sympathetic and parasympathetic systems.

What neurotransmitter-receptor pair is used in the autonomic ganglion of BOTH divisions of the autonomic nervous system?

How are the postganglionic autonomic synapses similar and different than the synapses in the neuromuscular junction?

Hint, a lot of this work is summarized by your in-class handout!

In the sympathetic division, what neurotransmitter-receptor pair is used in the ganglion? What about at the postganglionic synapse?

Give several examples of how the parasympathetic system affects different tissues (for example, how does it affect heart rate, salivation, rate of digestion, airways)

Describe how different types of adrenergic receptors can cause different responses to the same neurotransmitter.

As an example, explain how this works to modulate the diameter of arteries in the digestive system and blood vessels in the skeletal muscles during a systemic sympathetic response.

Hint, this is summarized in your in-class handout!

You can review the adrenal medulla material (it will be relevant in 40C as well), but note I won’t ask you any questions about it!

In the parasympathetic division, what neurotransmitter-receptor pair is used in the ganglion? What about at the postganglionic synapse?

Compare and contrast nicotinic receptors and muscarinic receptors.

Give several examples of how the parasympathetic system affects different tissues (for example, how does it affect heart rate, salivation, rate of digestion, airways)

Again, this is summarized by our in-class activity!

Multiple Sclerosis and the Myelin Sheath

2-Minute Neuroscience: Synaptic Transmission

2-Minute Neuroscience: Synaptic Transmission

What is the trigger for neurotransmitter release from a synapse?

 Copilot Using the web

The trigger for neurotransmitter release from a synapse involves a series of events that occur at the chemical synapse. Let me break it down for you:


Nerve Action Potential: When an action potential (a rapid change in voltage) propagates down the axon of a presynaptic neuron, it depolarizes the synaptic terminal.

Voltage-Gated Calcium Channels: The depolarization caused by the action potential opens voltage-gated Ca2+ channels in the presynaptic terminal, allowing calcium ions (Ca2+) to enter.

Exocytosis of Vesicles: The influx of calcium serves as the signal to trigger exocytosis of presynaptic vesicles. These vesicles contain neurotransmitters (such as acetylcholine, ACh).

Diffusion of Neurotransmitter: The released neurotransmitter (ACh) diffuses across the narrow synaptic cleft and binds to nicotinic ACh receptors on the postsynaptic cell membrane.

Postsynaptic Response: Binding of ACh to its receptors opens non-selective cation channels (allowing both K+ and Na+ ions to flow), leading to a local depolarization called the end-plate potential. If the depolarization reaches firing threshold, it triggers an action potential in the postsynaptic cell, which can lead to muscle contraction or other responses12.

In summary, the increase in internal Ca2+ is a crucial signal that initiates neurotransmitter release at chemical synapses. This process is conserved across all chemical synapses in the nervous system1. If you have any more questions or need further clarification, feel free to ask! 😊


Learn more


1


uw.pressbooks.pub

2


khanacademy.org

3


britannica.com

4

openbooks.lib.msu.edu

+2 more




Answer from this page instead

What are some common neurotransmitters?

How does synaptic plasticity work?

Tell me more about the postsynaptic response.

Week 3 guided question

  • What types of neurotransmitters are generally inhibitory?
GABA 
  • What types are generally excitatory?
Glutamate 
  • What is the trigger for neurotransmitter release from a synapse?
Both EPSP and IPSP caused neurotransmitters release by presynapse.
  • Outline/draw the steps of synaptic transmission.

  • How are neurotransmitters cleared from the synaptic cleft?
 (3 ways!)

The Difference Between Agonists vs. Antagonists

Neuron #1 sends an IPSP that changes the membrane -30mV Neuron #2 sends an EPSP that changes the membrane +10mV Does Neuron #3 send an action potential down its axon?


 

Now pull out your notes for spatial vs. temporal summation. Then check out the synapse below. If Neuron #1 and 2 trigger graded potentials of the same amplitude at the same time in neuron #3, does Neuron #3 send an action potential?


 

How are EPSPs (excitatory post-synaptic potentials) and IPSPs (inhibitory post synaptic potentials) associated with hyperpolarization or depolarization?

 How are EPSPs (excitatory post-synaptic potentials) and IPSPs (inhibitory post synaptic potentials) associated with hyperpolarization or depolarization?


  EPSPs are triggered by depolarizing graded potentials 

  EPSPs are triggered by hyperpolarizing graded potentials 

  IPSPs are triggered by depolarizing graded potentials 

  IPSPs are triggered by hyperpolarizing graded potentials 



reference video https://www.youtube.com/watch?v=KQOM_sXBtbw

Depolarizing local potentials are caused by Na+ influx via:

 Depolarizing local potentials are caused by Na+ influx via:


  Na+/K+ pumps. 

  Na+/Cl– symporters. 

  leak channels. 

  gated ion channels. 

reference insight 




Hyperpolarizing graded potentials can be caused by: (choose all the correct answers)

 As you learned, graded potentials can be hyperpolarizing or depolarizing. 

The ions that flow in @ the dendrites/soma will diffuse outwards in all directions.

 Some will end up at the axon hillock where they will either trigger an action potential (A.P.) or not.


Consider:


An A.P. is triggered when a threshold potential of -55mV is reached at the hillock.

Hyperpolarizing graded potentials would drive the membrane more negative than -70mV

Depolarizing graded potentials would drive the membrane more positive than -70mV

Review what types of ion channels can be opened @ dendrites/soma (last week's lecture)

Hyperpolarizing graded potentials can be caused by: (choose all the correct answers)

  1.   Opening of photo-gated Cl- channels 
  2.   Opening of ligand-gated Ca2+ channels 
  3.   Closing of voltage-gated Na+ channels 
  4.   Opening of mechanically-gated K+ channel

reference key insight 




Temporal vs. Spatial Summation