Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Muscle/nerves (F&F) > Synaptic Transmission > Flashcards

Synaptic Transmission Flashcards

1
Q

Steps of Synaptic transmission at the neuronal junction

A
  1. Action potential reaches the end of the presynaptic neuron
  2. voltage-gated Ca channels open in response and cause in influx of Ca 2+ into the neuron.
  3. Ca causes movement of synaptic vesicles with neurotransmitters to move to edge and release the neurotransmitters outside
  4. Neurotransmitters bind to receptors on post-synaptic neuron causing ligand-gated ion channels to open and an influx of ions into the neuron
  5. If a large enough change, then a new Action potential can occur
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Role of calcium in Neurotransmitter release

A
  1. An increase (more minor) of Ca in pre-synaptic neuron causes vesicles to move to active zone at edge of neuron for neurotransmitter release
  2. high levels of Ca in the pre-synaptic membrane stimulates fusion of vesicles because synaptotagmin binds Ca and interacts with SNARE proteins
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Important receptors on vesicles in pre-synaptic neuron

A
  1. synaptotagmin
  2. SNARE
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Steps of vesicle neurotransmitter release

A
  1. Action potential arrives, triggering the opening of voltage-gated Ca channels in pre-synaptic membrane
  2. Increase in Ca causes vesicles with neurotransmitters to move towards the active zone (edge of neuron to be released)
  3. Synaptotagmin on vesicle binds with Ca and interacts with the SNARE proteins to fuse vesicle and release neurotransmitters outside neuron to be picked up by post-synaptic neuron
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Action potential and neurotransmitter release

A
  • every single AP will release same amount of neurotransmitter to the synaptic cleft
  • high frequency of AP will result in more neurotransmitters being released into the cleft
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

When will the post-synaptic neuron be turned “on”?

A

Will be on if there are neurotransmitters within the cleft

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Steps of the Chemical synapse

A
  1. Action potential, opening of Ca channels in pre-synaptic neuron will release neurotransmitters into the cleft
  2. Always same amount of neurotransmitters released per AP
  3. Neurotransmitter will bind to the postsynaptic receptor proteins causing ion channels to open
  4. When transmitter is removed from the cleft, fused membrane is recycled back into the neuron
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Mechanisms of neurotransmitter removal

A
  1. Enzymatic breakdown within synaptic cleft
  2. Reuptake of neurotransmitter
  3. Diffusion
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Removal of neurotransmitters by Enzymatic breakdown within synaptic cleft

A

Acetylcholinesterase in the post-synaptic membrane will breakdown acetylcholine into choline and acetic acid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Removal of neurotransmitters by reuptake of neurotransmitter

A

Neurotransmitter is taken up by specific transporters on the presynaptic neuron (eg. serotonin, norepinephrine) or on astrocytes (eg. glutamate)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Removal of neurotransmitters by diffusion

A

Occurs to a certain extent with all neurotransmitters

Only mechanism of removal for peptide neurotransmitters (Substance P)

Slow, therefore long duration of action if this is only mechanism of removal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Substance P

A

a peptide neurotransmitter

A potential biomarker of pain assessment

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

How do neurotransmitters initiate a response?

A

Neurotransmitters influence cellular activity based on receptor type, altering the membrane potential directly or indirectly through secondary messenger systems

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

How to neurotransmitters produce different responses?

A

A single neurotransmitter can elicit varied responses by binding different receptor subtypes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are the two receptor types?

A
  1. Ionotropic receptors (fast)
  2. Metabotrophic receptors (slow)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Ionotropic receptors

A
  • fast
  • directly coupled to ion channels, causing immediate membrane potential changes upon binding
17
Q

Metabotrophic receptors

A
  • slow
  • influences ion channels indirectly through intracellular signalling pathways (receptor in the post-synaptic membrane and intracellular messenger)
18
Q

Important neurotransmitters of the CNS

A

Amino acids:
1. glutamate
2. aspartate
3. glycine
4. GABA

19
Q

Excitatory neurotransmitters of the CNS

A

Glutamate
Aspartate

Cause depolarizing postsynaptic potential

20
Q

Inhibitory neurotransmitters of the CNS

A

Glycine
GABA

Causes hyperpolarizing postsynaptic potential

21
Q

Neurotransmitters of the PNS

A
  1. Acetylcholine (Ach)
  2. Norepinephrine
  3. Epinephrine
22
Q

Acetylcholine receptor in somatic nervous system

A

Nicotinic cholinergic receptor (N)

  • ionotropic
  • somatic system (skeletal muscle)
23
Q

Acetylcholine receptor in autonomic system

A

Muscarinic cholinergic receptor (M)

  • metabotrophic
24
Q

Epinephrine and norepinephrine receptors

A

alpha-adrenergic receptor
beta-adrenergic receptor

  • Metabotrophic
25
Q

CNS synaptic architecture

A
  • Complex
  • Axosomatic synapse (axon to cell body)
  • Axodendritic synapse
    (Axon to dendrite)
  • Axoaxonic synapse
    (axon to axon)
26
Q

PNS synaptic architecture

A

SIMPLE

  • straightforward input and output pathway from simple synapses at neuromuscular junctions
27
Q

Myelination in the CNS vs. PNS

A

CNS: one oligodendrocyte insulates many axons

PNS: one schwann cells insulates one axon ???

28
Q

Regeneration in peripheral nerves

A
  1. nerve fiber and its myelin sheath distal to the injury degenerates
  2. Schwann cells proliferate to form a column to guide axon regeneration (~0.5-3 mm/day)
  3. Functional connections with muscle established after several months
29
Q

Neurotransmitter diversity (CNS vs. PNS)

A

CNS: uses a variety of NTs, both inhibitory and excitatory for complex info processing

PNS: limited NT use (acetylcholine, epinephrine, norepinephrine)

30
Q

Regeneration capacity in CNS vs. PNS

A

CNS: limited due to complex microenvironment

PNS: possible when damage is moderate. Schwann cells play a pivotal role by guiding and supporting axonal regrowth and target innervation

Muscle/nerves (F&F) (9 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions