Phys 1 synaptic transmission Flashcards Preview

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Flashcards in Phys 1 synaptic transmission Deck (20)
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1
Q

Types of synaptic transmission?

A

Electrical

Chemical

2
Q

Electrical synaptic transmission

vs

Chemical Synaptic transmission

A

E.

  • Fast
  • Gap junctions
  • multidirectional
  • (think synaptic cleft are connected)
  • ex. Heart

C.

  • Slower
  • synaptic gap (normal synaptic cleft)
  • unidirectional
  • ex. ANS
3
Q

What are the sequence of events in a chemical synapse?

A
  1. Neurons synthesize NTs
  2. NTs stored in axon terminal
  3. Action potential triggers release of NTs
    1. this usually happens by AP causes Ca channel to open which causes NTs to fuse and leave
  4. NT travel to bind receptors
  5. Post synaptic response= change in membrane pot
  6. NTs: reuptake, diffuse away, break down
4
Q

Criteria for NTs?

A
  1. synthesis in pre-Synaptic neuron
    1. Food substrates (aa)
    2. soma of neurons
  2. Released in response to pre-synaptic AP
    1. Ca dependent
    2. Quantal Hypothesis
    3. NT release= [increse Ca]+[increse in AP]
  3. post synaptic receptors receive/respond to signal
  4. NTs must somehow be inactivated
    1. drugs can alter this
5
Q

what is the quantal hypothesis

A

each time synaptic vesicle released 5000 to 10000 molecules of NT released

More NTs needed more AP needed

6
Q

Neurotransmitter classes

A

Choline esters

Biogenic Amines

AA

Neuropeptides

7
Q

Choline esters

A

acetylcholine

  • muscarinic mAChR
  • Nicotinic nAChR
8
Q

Biogenic Amines

A

DA, EP, NE, 5-HT (serotonin)

9
Q

AAs

A

glutamate, glycine, GABA

10
Q

Neuropeptides

A

ACTH, Glucagon, Endorphins

11
Q

Postsynaptic response can have what outcomes?

A

AP

EPSP- Excitatory postsynaptic potential

  • Closer to threshold

IPSP- inhibitory postsynaptic potential

  • further from theshold
12
Q

EPSP

A

excitatory

  • K out of cell
  • Na into cell
  • Net positive change
  • get closer to threshold
13
Q

IPSP

A

further from threshold

  • K out of cell

Or

    • charge into cell (Cl-)
14
Q

Summation (Not specific types)

A

Balancing act EPSP+IPSP

keep eachother in check will be movement from resting membrane potential but not as large as either by itself

15
Q

Summation types

A

Spatial

Temporal

16
Q

Spatial

A

EPSP only

  • many pre-synaptic neurons
  • signal at the same time
  • causes a large jump in one step
17
Q

Temporal

A

EPSP only

  • One pre-synaptic neuron
  • Pre-synaptic signal happens over time
  • The one nerve will fire multiple times until it reaches the threshold then it will depolarize
18
Q

Types of acetylcholine receptors

A

Nicotinic

Muscarinic

19
Q

Nicotinic receptors

A

ionotropic

  • ACh bind nAChR
  • increase in Na and K perm
  • Membrane depolarization
  • AP excitation

skeletal muscle

20
Q

Muscarinic receptors

A

Metabotropic

  • G-protein coupled receptor GPCR
  • ACh bind nAChR
  • release alpha subunit which is bound to GTP
  • Beta and gamma go and elicit responses

Autonomic NS

Parasympathetic