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1. Hodgkin-Huxley Model Noam Shor
Idan Plonsky
2. Introduction Hodgkin-Huxley model is a model that tries to simulate the biological nerve cell.
What is a model?
Mathematical representation.
Logical description of a system.
3. Motivation There are some biological phenomena that we’d like to understand
Reverse engineering the brain.
Analogue : Electrical circuits design.
Once we have the model, we can experiment and change the parameters.
4. Three phases Biological Side.
Electrical Side (derived from 1).
Mathematical side.
5. Biological Side - intro Nerve Cells Environment.
Nerve cell structure.
Axon Structure
Electricity flow.
6. Nerve Cells Environment Neuron receives action potentials in the dendrites and sums it all.
If the sum is higher than a certain threshold, an action potential is created and passed through the axon to the presynaptic membrane.
7. Biological Side Nerve cell structure
8. Biological Side – Axon structure Axon include the following elements:
Myelin.
Membrane.
Nodes of Ranvier.
Sodium and Potassium.
Sodium Channels.
Potassium Channels.
Pump.
9. Axon structure – cont’ Inside the axon – lots of potassium K+
Outside the axon – lots of Sodium Na+
In addition – A-
10. Rest potential Three channels keep the rest potential.
Sodium Channels (Na+) inward, increase the voltage.
Potassium Channels (K+) outward, decrease the voltage.
Pumps – Take out Na+, Insert K+ - keeps the voltage steady.
11. Action Potential
12. Electric Side
13. Mathematical Side Few rules (reminders):
Ohm rule V = I * R
G = 1/R
I = G * V
I = C * (dv/dt)
14. Computer science side
15. Axon Experiments
16. Few formulas…
17. Computer science side
18. Experiment 1
19. Experiment 1 – Cont’
20. Experiment 2
21. Reference www.ces.clemson.edu
http://www-2.cs.cmu.edu/~dst/HHsim/
Technion lecture.
Open University.