Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Cellular Neuroscience > Brain Electrophysiology I & II > Flashcards

Brain Electrophysiology I & II Flashcards

(82 cards)

Start Studying
1
Q

what were the results of the Hodgkin and Huxley (1939) model?

A

1) axons at rest are electrically polarized
2) -60mV inside v.s the outside

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

what were the methods of the Hodgkin and Huxley model?

A

voltage clamp experiments and by varying extracellular Na and K concentrations

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

what is an action potential?

A

when polarization of the membrane is removed (due to depolarization)

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

what is hyperpolarization?

A

a rapid swing in membrane potential to more negative values following depolarization

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

what is after-polarization?

A

a period of increased polarization

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what forces determine the passive distribution of ions?

A

electrical and thermodynamic forces

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

how do ions move down their concentration gradients?

A

via ion channels or diffusion

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

what does the movement of ions result in?

A

redistribution of electrical charge (voltage gradient), which can cause either hyperpolarization or depolarization

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

what is the reversal potential?

A

the membrane potential at which the net current flips direction

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

what is the equilibrium potential?

A

the membrane potential at which there is not net movement of ions, which is basically a balance between voltage and concentration gradients

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

how can the equilibrium potential be calculated?

A

Nernst Equation

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

what are the ions that contribute to the resting membrane potential?

A

Na, K, Cl
the membrane is not at equivalent potentials for one ion (as they all contribute to the resting potential

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

what do ion pumps do?

A

maintain concentration gradients

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

how do ion pumps maintain the concentration gradient?

A

by actively transporting ions

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

what is one example of an ion pump?

A

the Na/K ATPase pump

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

how is the Na/K ATPase pump get stimulated?

A

by increased of intracellular Na

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

what does the Na/K ATPase pump move in and out?

A

Na out and K in

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

the Na/Ca2 exchanger is an example of an…

A

ion pump

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

a chloride-bicarbonate exchanger is an example of an…

A

ion pump

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

which ions increase in conductance during an action potential?

A

Na and K

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Na and K conductance causes the membrane to become more positive or negative?

A

positive, in order to reach depolarization

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

what happens after an action potential?

A

the membrane potential re-polarizes (becomes more negative) than resting (hyperpolarization)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

what is a transient inward current?

A

a more positive charge inside of the cell

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

what happens in the giant squid action when you increase the voltage from -60mV to 0mV?

A

produces a transient inward current and it is followed by a sustained outward current

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
what is a pharmacological blockade?
drugs or substances that inhibit or block specific physiological or biochemical processes in the body
26
what does tetradotoxin (TTX) block?
Na channels
27
when you increase the membrane potential in the presence of TTX, what ion current increases?
K only
28
what does tetraethylammonium (TEA) block?
K channels
29
when you increase the membrane potential in the presence of TEA, what ion current increase?
Na only
30
how do K channels open?
via their voltage sensitive gates and depolarization
31
how do K channels close?
via depolarization, which leads to deactivation
32
what are the different states that a Na channel can be in throughout an action potential?
activated, deactivated, and inactivated
33
what is the inactivation state of the Na channel?
when the channel is inactive despite maintained depolarization
34
what is "deinactivation"?
the removal of the inactivation state of the Na channel
35
what Na gate opens during depolarization?
activation gates
36
what Na gates close during depolarization?
inactivation gates
37
what Na gate closes during repolarization?
activation gates
38
what Na gates open during repolarization?
inactivation gates
39
what is the action potential threshold?
-55mV
40
how does the movement of Na ions depolarize the axon?
by moving more Na inside, this opens more Na channels
41
what are the two voltage-sensitive processes that Na channels display?
1) activation -> deactivation 2) inactivation -> deinactivation
42
what is propagation?
initiation
43
in what two places can action potentials start?
1) the axon initial segment 2) the axon hillock
44
where does the action potential move (2 directions)?
1) propagates down the axon 2) antidromically backwards to the dendrites
45
what is antiromically?
the propagation of an action potential in the opposite direction to the normal flow
46
what is the threshold for AP generation in the initial segment?
low threshold
47
what is the density of Na channels in the initial segment?
high density
48
how can the speed of action potentials be affected?
by myelination
49
how do unmyelinated axons move the action potential?
by depolarizing adjacent regions of the membrane
50
how do myelinated axons move the action potential?
by regenerating the action potential ate the nodes of ranvier
51
what does the axon look like at the nodes of ranvier?
exposed to the external medium
52
what are the five different firing patterns that can be performed by neurons?
1. regular firing 2. rhythmic bursts 3. short duration 4. spontaneous low frequency discharges 5. steady-slow discharges
53
what is regular firing?
trains of action potentials (one spike at a time)
54
what is a feature of regular firing?
spike frequency adaptation
55
what is spike frequency adaptation?
the tendency to slow down in frequency with time
56
what is an example of regular firing?
cortical/hippocampal pyramidal cells
57
what are rhythmic bursts of action potentials?
when clusters of APs are generated through activation of Ca2+ currents
58
what is an example of rhythmic bursts of action potentials?
thalamic relay neurons (they can perform phasic bursts and slower discharges)
59
what are short duration action potentials?
action potentials that have high frequencies (>300 HZ)
60
what is an example of short duration action potentials?
fast spiking neurons like GABAergic interneurons
61
what cells display spontaneous low frequency discharges?
neuromodulatory neurons
62
what is an example of a neuromodulatory neuron?
dopaminergic neurons
63
what cells display steady-slow discharges?
medial hebanular neurons
64
what are the 3 main features by which ion currents are characterized by
1) the type of ions conducted by channels 2) the voltage and time dependence 3) their sensitivity to second messengers
65
what are the different types of Na currents?
1) I Na(t) 2) I Na(p)
66
what are the features of the I Na(t) current?
transient and can rapidly activate and deactivate action potentials
67
what are the features of the I Na(p) current?
persistent and non-inactivating
68
what does non-inactivating enhance?
depolarization and steady-state firing
69
what are the different types of Ca currents?
1) I (L) 2) I (T) 3) I (P)
70
what are the features of I (L) currents?
high threshold currents, long lasting, and slowly inactivate
71
what can display an I (L) current?
dendritic spikes
72
what are the features of an I (T) current?
low threshold, transient, and rapidly inactivating
73
what firing pattern displays an I (T) current?
rhythmic burst firing
74
what cells perform an I (P) current?
purkinje cells (their dendritic spikes)
75
what are the different types of K currents?
1) I (K) 2) I (C) 3) I (AHP) 4) I (A) 5) I (H)
76
how is the I (K) current activated?
by strong depolarization and repolarization of the action potential
77
how is the I (C) current activated?
by increasing calcium levels and acton potential repolarization
78
what part of the action potential displays I (AHP) current?
afterhypolarization (because of slow adaptation of action potential discharge)
79
what is the I (A) current?
transient inactivating current
80
how does the I (H) current occur?
via a depolarizing current activated by hyperpolarization
81
what are the two different patterns of activity that thalamic relay neurons display?
rhythmic bursts and tonic firing
82
when does the transition from rhythmic burst (phasic) to tonic firing occur in thalamic cells?
during sleep to waking

Cellular Neuroscience (1 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions