1. Week 7a: Action Potential Part 2: Spike patterning
BIOL3833
Week 7a: Action Potential Part 2: Spike patterning

2. The Plan
Today:
Brief lecture: Action potential patterning (~20 minutes)
Begin simulations for homework 4 (remainder of class)

3. Advanced ion channels Delayed-rectifier K+ channels (gK)
A-type K+ channels (gA)
M-type K+ channels (gM)
AHP channels (gAHP)
BK channels (gC)
T-type Ca2+ channels (pT)
L-type Ca2+ channels (pL)

4. Action potential frequency and patterning
Spike frequency adaptation
Dynamic range & intensity coding
Multiple operational modes

5. Spike frequency adaptation

6. Why is spike frequency adaptation important?
Filtering out responses to things that aren’t changing

7. Spike frequency adaptation is very plastic

9. Dynamic range
Dynamic range refers to the range of firing frequencies that a neuron can produce as their excitatory inputs increase.

10. Saturation
Dynamic
Range
Subthreshold

11. Why dynamic range is important

12. Dynamic range and spike frequency adaptation in sensory systems

13. Encoding visual information in the brain:

14. Thalamic relay neurons have multiple modes
Transfer mode
Multiple spikes
Wide dynamic range
Awake / High arousal
Burst mode
Slow rhythmic firing
Terrible dynamic range
Asleep / Low arousal
-55 mV
-65 mV
-75 mV

15. Why?
To transmit sensory information to the sensory cortex when we are awake, but to block that transmission when we sleep.

17. Disorders of thalamic relay neuron states
Absence seizures
Disorders of thalamic relay neuron states
What happens when these neurons slip into burst mode when they shouldn’t?