10. Physiology of nerve cells, synaptic transmission in the central nervous system Flashcards

1
Q

What does nervous system include?

A
  1. Neurons
  2. Neuroglial cells
  3. Blood vessels, connective tissue
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is neuron?

A

Function unit of the nervous system

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

What is neural circuits?

A

Interconnected neurons

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

4 types of neuroglial cells in CNS?

A
  1. Astrocytes
  2. Oligodendrocytes
  3. Microglia
  4. Ependymal cells
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

2 types of neuroglial cells in PNS

A
  1. Schwann cells
  2. Satellite cells
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are primary function of neurons?

A
  1. Transmission of information
  2. Processing of information

In the form of special electrical signals

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

Describe input and output of neural information

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Identify 4 basic regions of neuron

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Identify parts of neuron

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

Function of cell body

A
  1. Metabolic control center
  2. Manufacturing and recycling plant (nucleus, ER, Golgi - protein synthesis)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

4 characteristics of action potential

A
  1. Graded
  2. Localized
  3. Spreads with decrement
  4. Low amplitude
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Function of dendrites

A

Receive incoming signals from other neurons

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

Function of axon

A

transmits outgoing signals to axon terminals

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

Function of axon terminals

A

Form synapses, where outgoing signals pass to (the dendrite of) another neuron

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

3 examples of electrotonic potentials of neurons

A
  1. Receptor potential (generator potential)
  2. Excitatory postsynaptic potential (EPSP)
  3. Inhibitory postsynaptic potential (IPSP) (graded, localized, spreads with decrement, low aplitude)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

4 characteristics of action potential

A
  1. All-or-none
  2. Regenerating
  3. Spreads without decrement
  4. High amplitude

(a spreading wave of voltage-gated Na+ channel activation)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Example of receptor potential

A

Pseudounipolar sensory neuron

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What type of receptor is receptor potential?

A

Mechanoreceptor

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What type of receptor is receptor potential?

A

Mechanoreceptor

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

How does receptor potential work?

A
  1. Mechanosensitive cation channel: closed
  2. Mechanical stimulus
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Sensory receptor: generation of action potential
-> How does it happen?

A

Electrotonic depolarization
-> spreads with decrement
-> Voltage-gated Na+ channels open (TTX-sensitive, lidocaine)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What are the 3 channels participating in generation of action potential in neuron?

A
  1. Mechanosensitive Na+
  2. Voltage-gated Na+
  3. Voltage-gated K+
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Sensory receptor: generation of action potential
-> Identify

A

Subthreshold mechanical stimulus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Sensory receptor: generation of action potential
-> Identify

A

Suprathreshold stimulus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Maintained receptor potential induces repititive AP firing
-> What will happen at this time?

A

Stimulus to sensory receptor

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Maintained receptor potential induces repititive AP firing
-> What will happen at this time?

A

Suprathreshold receptor potential (electrotonic depolarization) is present

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Maintained receptor potential induces repititive AP firing
-> What will happen at this time?

A
  1. Repolarization below threshold
  2. Voltage-gated channels return to the closed state (from the inactivated state)
  3. Voltage-gated K+ channels close
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Maintained receptor potential induces repititive AP firing
-> What will happen at this time?

A

Resting state

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Maintained receptor potential induces repititive AP firing
-> What will happen at this time?

A
  1. Voltage-gated K+ channels open
  2. Voltage-gated Na+ channels inactivate
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What does the amplitude of receptor potentiall determine?

A

Action potential frequency

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

The amplitude of receptor potential determine AP
-> What does the pink part mean?

A

Suprathreshold, small stimulus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

The amplitude of receptor potential determine AP
-> What does the pink part mean?

A

Strong stimulus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

How is AP frequency affected by the strength of stimulus

A

The stronger the stimulus
-> The higher the amplitude of receptor potential
-> The higher the AP frequency

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

What are the 2 main classes of synapses?

A

Electrical and chemical synapses

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

What are the mechanisms of eletrical and chemical synapses?

A

E: Electric conduction
C: Chemical neurotransmitter

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

What are the directions of transmission?

A
  1. Bidirectional
  2. Unidirectional (from pre- to postsynaptic cell)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

Do electrical and chemical synapses have delay?

A

E: No
C: 1 - 5 msec

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

What are the localizations of electrical and chemical synapses?

A

E: CNS & PNS, smooth muscle, heart muscle
C: CNS & PNS

39
Q

What are the structures of electrical and chemical synapses?

A

E: gap junction
C: Pre-, postsynaptic membrane, vesicles

40
Q

What is the function of gap junctions (electrical synapse)

A

Synchronization: depolarization directly spreads from one cell to the other

41
Q

How does electrical synapse work in case of gap junctions?

A
  1. AP arrives (depolarization)
  2. Ca2+ channels open
  3. Exocytosis
  4. Transmitter binds to postsynaptic receptor
  5. Postsynaptic electrotonic potential develops
42
Q

what is the voltage of depolarization for miliseconds? (excitatory postsynaptic potential)

A

0.1 - 5 mV

43
Q

What is excitatory postsynaptic potential caused by?

A

The opening of ligand-gated non-selective cation channels

44
Q

What is the most frequent transmitter for EPSP?

A

Glutamate

45
Q

What are the 2 glutamate receptor types?

A
  1. Ionotropic receptors (ligand-gated channels)
  2. Metatropic receptor (G-protein coupled, 7TM)
46
Q

What are the 2 subtypes of ionotropic Glu receptors (ligand-gated ion channels)?

A
  1. AMPA
  2. NMDA
47
Q

Characteristic of AMPA (a subtype of ionotropic Glu receptors)

A

Permeable to univalent cations (Na+ influx)

48
Q

What are required for the opening of NMDA, a subtype of ionotropic glutamate receptors?

A

Univalent cations and Ca2+ depolarization is required for opening

49
Q

2 examples of metatropic receptors

A
  • G protein coupled
  • 7TM
50
Q

What is the voltage of hyperpolarization for miliseconds of inhibitory postsynaptic potential?

A

0.1 - 5 mV

51
Q

What is the voltage of stabilization for miliseconds of inhibitory postsynaptic potential?

A

Stabilization of Em at negative values

52
Q

inhibitory postsynaptic potential (IPSP) is typically caused by __

A

the opening of ligand-gated chloride channels (or opening K+ channels)

53
Q

What is the most frequent transmitter for inhibitory postsynaptic potential (IPSP)

A

GABA

54
Q

What are the 2 GABA receptor types for inhibitory postsynaptic potential (IPSP)?

A
  1. GABA-A receptor: ligand-gated Cl- channel
  2. GAPA-B receptor: 7TM
55
Q

What can activate GABA-A receptor type?

A

Benzodiazepin

56
Q

Describe 7TM (GABA-B receptor)

A
  • Gi protein
  • Opening of K+ channel
57
Q

How do we summate postsynaptic potentials?

A

EPSP + IPSP

58
Q

What happen if we have small summated EPSP?

A

Low AP frequency

59
Q

What is the strength of AP if we have large summated EPSP?

A

High AP frequency

60
Q

The amplitude of summated post synaptic potentials determine AP

What do the green and blue arrows indicate?

A

G: Depolarizinng effect of summated EPSPs
B: Repolarizing effect of voltage-gated K+ channels

61
Q

One neuron has only one input/ouput
-> T/F?

A

False
-> One neuron - many input/output (through synapses)

62
Q

What are the 2 types of summation do we have?

A

Spatial and temporal summations

63
Q

Where can you high density of voltage-gated Na+ channels on a neuron?

A
  • High density of these channels on axon hillock
  • Less on dendrites and cell body
64
Q

If we combine EPSPs and IPSPs and reach the threshold of Na+
-> what will we obtain?

A

Action potential

65
Q

The amplitude of combined postsynaptic potential is encoded in ___

A

AP frequency

66
Q

Can only 1 synapse evoke AP?

A

NO!!!!!

67
Q

What is the characteristic AP pattern?

A

Special channel repertoire

68
Q

Where are synaptic vesicles synthesized?

A

In cell body

69
Q

How are synaptic vesicles transported to the axon terminal?

A

By axonal transport

70
Q

How does axonal transport work?

A

Synaptic vesicles are transported along microtubules with motor proteins

71
Q

What are the 2 types of axonal transport?

A
  1. Anterograde
  2. Retrograde
72
Q

What is anterograde axonal transport?

A

movement of molecules/organelles outward, from the cell body (also called soma) to the synapse or cell membrane.
-> With the help of kinesins

73
Q

How can anterograde axonal transport speed up?

A

By using vesicular cargo, 50 - 400 mm/day

74
Q

How can anterograde axonal transport slow down?

A

by using proteins (1 - 10mm/day)

75
Q

What is retrograde axonal transport?

A

Retrograde axonal transport conveys materials from axon to cell body.

76
Q

Which molecules assist in retrograde axonal transport?

A

Dyneins

77
Q

What are the constiuents of synaptic vesicles?

A
  1. Neurotransmotter
  2. Proteins involved in exocytosis
  3. Proteins for transmitter uptake (into the vesicle)
78
Q

How does the uptake of neurotransmitter into the synaptic vesicles?

A

By using…
1. V-type proton pump (ATPase)
2. Neurotransmitter-proton exchanger

79
Q

Where is the neurotransmitter present?

A

In presynaptic nerve terminal

80
Q

A neurotransmitter is synthesized by ___

A

Presynaptic neuron

81
Q

A neurotransmitter is released in response to __

A

presynaptic depolarization

82
Q

There are not any specific receptors on the post synaptic cell for a type of neurotransmitter
-> T/F

A

False
-> there are specific receptors on the postsynaptic cell

83
Q

What will neurotransmitter cause in the target cell?

A

A response

84
Q

What are the 3 common types of neurotransmitters?

A
  1. Small-molecule neurotransmitters
  2. Peptide neurotransmitters, neuromodulators
  3. Gas neurotransmitters
85
Q

What are the 4 subtypes of small-molecule neurotransmitters?

A
  1. Amino acids
  2. Acetylcholine
  3. Biogenic amines
  4. ATP, adenosine
86
Q

List 3 amino acids that are small-molecule neurotransmitters

A
  1. Glutamate
  2. GABA
  3. Glycine
87
Q

List 3 biogenic amines which are small-molecule neurotransmitters

A
  • Catecholamines
  • Serotonin
  • Histamine
88
Q

Give 3 examples of catecholamines that are small-molecule neurotransmitter

A
  1. Dopamine
  2. Norepinephrine (=noradrenaline)
  3. Epinephrine (=adrenaline)
89
Q

Give 5 examples of peptide neurotransmitters (a.k.a. neuromodulators)

A
  1. GI hormones
  2. Pituitary hormones
  3. Hypothalamic hormones
  4. Opioid peptides
  5. Neuropeptide Y
90
Q

What are the 4 examples of neuropeptide Y which are peptide neurotransmitters (= neuromodulators)?

A
  • CGRP
  • Substance P
  • Neuropeptide K
  • Galanin
91
Q

What is an example of gas neurotransmitter?

A

NO (nitric oxide)

92
Q

3 steps of termination of transmitter effect

A
  1. Diffusion
  2. Reuptake by presynaptic terminal (in general, cotransport with Na+)
  3. Enzymatic breakdown (acetylcholinesterase)
93
Q

Is binding to receptors a major pathway of elimination?

A

NO!!!!