Voltage Gated Ion Channels Flashcards
1
Q
Na+ Channel
A
- Fast kinetics (open)
- Inactivation
2
Q
Delayed Rectifier K+ Channel
A
- Slow kinetics (open/close)
- No inactivation
3
Q
Neurons with more delayed rectifier K+ channels?
A
- Repolarization occurs a lot more quickly
- Large maximum spike rate
4
Q
(A-Type) K+ Channel
A
- Fast kinetics
- Inactivation
- Low threshold (some channels are inactivated at rest)
- Hyperpolarization recruit more “A-type K+ Channel”
- Slight delay to action potential/fewer spikes occurs because K+ channels have to close in order for effective action potential to happen
5
Q
(LVA or T-Type) Low-Voltage Activated Ca2+ Channel
A
- Fast kinetics
- Inactivation
- Low threshold (some channels are inactivated at rest)
- Hyperpolarization recruit more “T-type Ca2+ Channel” that are inactivated at rest
- Result in increased spiking as positive charges enter the cell
6
Q
(HVA or L-Type) High-Voltage Activated Ca2+ Channel
A
- Fast kinetics (open)
- Slow inactivation
- High threshold (channels open during an action potential)
- Ca2+ accumulate with each action potential
7
Q
Ca2+ Gated K+ Channel
A
- Gated by intracellular Ca2+
- Slow kinetics
- No inactivation
- Neurons with HVA Ca2+ channels AND Ca2+ Gated K+ channels show spike frequency adaptation (decreased firing rate over time)
8
Q
(HCN) Hyperpolarization-Activated Cyclic Nucleotide-Gated Cation Channel
A
- Gated by cyclic nucleotides
- Non-selective for cations (K+ flow out, Na+ flow in, and Ca2+ flow in)
- Slow kinetics
- No inactivation
- HCN channels can excite a hyperpolarized neuron, resulting in intrinsic spiking
9
Q
Low Threshold Channels
A
- Open when voltage exceeds a value that is LOWER than resting potential
- Open during rest (if inactivation particle, channel inactivates at rest)
10
Q
High Threshold Channels
A
- Open when voltage exceeds a value that is HIGHER than action potential threshold
- Open during action potential
11
Q
Hyperpolarization Gated Channels
A
- Open when voltage is LOWER than a certain value
