Nerve Muscle Synapse Lecture 4 Flashcards Preview

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Flashcards in Nerve Muscle Synapse Lecture 4 Deck (28)
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1
Q

Where would you find neurotransmitters?

A

in vesicles within the pre-synaptic terminals

2
Q

Receptors on the post-synaptic cell are also ____ channels

A

Ion

3
Q

What type of synaptic transmission do most of the systems we talk about use?

A

Directly Gated

4
Q

Neurotransmitters can be ____\_or _____\_

A

Neurotransmitters can be excitatory or inhibitory

5
Q

afferent neurons use the excitatory neurotransmitter:

A

glutamate

6
Q

An interneuron can be either _____ or _____ but not both!

A

excitatory or inhibitory

7
Q

The space between the post-synaptic and pre-synatic cell is called:

A

The synaptic cleft

8
Q

An excitatory nt will have what effect?

A

Open up Na+ ion channel = Na+ flows through (into the cell making cell more positively charged) = depolarization in membrane of postsynaptic cell = EPSP

9
Q

What will be the effect on the post-synaptic cell if an inhibitory NT (___ or ___) binds?

A

What will be the effect on the post-synaptic cell if an inhibitory NT (Cl- or K_+_) binds?

Cl- or K+ channel opens = inside of cell becomes more negative (K+ will leave OR Cl- will enter) = IPSP

10
Q

In the post synaptic cell, what is generated is NOT an AP. If depolarization occurs we will see either an _____ (excitatory) or _____ (inhibitory)

A

EPSP - excitatory post-synaptic potential

IPSP - Inhibitory post-synaptic potential

11
Q

EPSP =

A

depolarization

12
Q

IPSP =

A

Hyperpolarization

13
Q

In directly gated chemical transmission, the effects are _____ and _____

A

Fast and short-lasting

14
Q

In the process of directly gated chemical transmission the receptor and the effector are:

A

the same molecule:

The receptor is located directly on ion channel

Molecule NT binds to receptor

Opens ion channel in receptor

15
Q

What is the main difference between Indirectly gated and directly gated chemical transmission?

A

The effector and receptor are the same molecule in directly gated but NOT in indirectly gated

16
Q

Indirectly gated chemical synaptic transmission involves a ______ (via G-proteins)

A

Indirectly gated chemical synaptic transmission involves a 2nd messenger System (via G-proteins)

17
Q

Indirectly chemical synaptic transmission:

Second messenger system uses ____ protiens.

Binding of NT receptor activates ____ which activates _____ which converts ATP into cAMP

A

Indirectly chemical synaptic transmission:

Second messenger system uses G proteins.

Binding of NT receptor activates GTP which activates Adenylyl cyclase which converts ATP into cAMP

  • Instead of simple ion flow = more long-term changes in the cell

Would occur during memory creation/learning etc

18
Q

**Compare indirectly gated chemical synaptic transmission to Directly Gated Chemical Synaptic Transmission

A

Directly Gated:

  • fast onset
  • short lasting
  • receptor and ion channel are single protein

Indirectly Gated

  • slow onset
  • Longer-lasting
  • receptor and effector are different molecules
19
Q

Chemical versus Electrical synapses:

  • Electrical synapses are _____
    • Great for stereotypical beh but difficult to change
    • ALWAYS _____
    • Cannot ____ neighbouring cells because of the flow of ions between the cells
  • Chemical synapses provide _____
    • Only synapse that you can achieve ____
    • Different NT have different effects = _____
    • _____\_: type, time, strength location
    • ________: changes in synaptic ____ and ____
A

emical versus Electrical synapses:

  • Electrical synapses are Inflexible
    • Great for stereotypical beh but difficult to change
    • ALWAYS excitatory
    • Cannot inhibit neighbouring cells because of the flow of ions between the cells
  • Chemical synapses provide flexibility
    • Only synapse that you can achieve inhibition
    • Different NT have different effects = Specificity
    • Complexity: type, time, strength location
    • Plasticity: changes in synaptic structure and function
20
Q

If an axon is myelinated, the action potential will travel down it via:

A

Saltatory electrotonic conduction

21
Q

What is the sequence of events during synaptic transmission?

(7)

A
  1. AP arrives in presynaptic terminal
  2. Presynaptic terminal depolarizes
  3. Voltage gated Ca2+ channels open
  4. Influx of Ca2+ into presynaptic terminal
  5. Increased Ca2+ causes synaptic vesicles to fuse with presynaptic membrane
  6. Transmitters released via exocytosis and diffuses across synaptic cleft to bind to and open ligand-gated ion channels
  7. Ions flow across membrane as dictated by their concentration gradents and depolarizes (EPSP) or hyperpolarizes (IPSP) post-synaptic cell (directly-gated)
22
Q

Excitatory NT

  • channels are:
  • Binding = ions flow across membrane results in _______
  • binding of ______ to receptor causes sodium ions to flow into the cell = post-synaptic cell more _____ charged = EPSP
A

Excitatory NT

  • channels are: Na+
  • Binding = ions flow across membrane results in depolarization of postsynaptic cell
  • binding of GLUTAMATE to receptor causes sodium ions to flow into the cell = post-synaptic cell more positively charged generates an: EPSP
23
Q

Inhibitory NT:

Generates ______ via _______

A

Inhibitory NT:

Generates IPSP via hyperpolarization

24
Q

What are the two options for a NT removed from it’s receptor?

A

Removed and recycled (taken up via endocytosis)

or

degraded (taken up by glia)

25
Q

What happens when glutamate binds to it’s receptor?

A

Opens Na+ channels = more positive post-syanptic cell = EPSP

26
Q

Glutamate is an _______ neurotransmitter

A

excitatory

27
Q

EPSPs are ________ (only depolarize a small fraction of what is required to get to threshold)

A

subthreshold

28
Q

GABA and Glycine are _______ Neurotransmitters and binding to receptor causes _____ channels to open

A

GABA and Glycine are Inhibitory Neurotransmitters and binding to receptor causes Cl- channels to open