HodgkinHuxley Model

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Hodgkin-Huxley Model

• Noam Shor
• Idan Plonsky

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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.

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Motivation

• There are some biological phenomena that wed
  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.

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Biological Side Nerve cell structure
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Biological Side Axon structure

• Axon include the following elements
• Myelin.
• Membrane.
• Nodes of Ranvier.
• Sodium and Potassium.
• Sodium Channels.
• Potassium Channels.
• Pump.

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Axon structure cont

• Inside the axon lots of potassium K
• Outside the axon lots of Sodium Na
• In addition A-

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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.

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Action Potential
Open Na channels
Open K channels
70mV
0mV
Hyper polarization
-70mV
Back to Rest
t
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Electric Side
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Mathematical Side

• Few rules (reminders)
• Ohm rule V I R
• G 1/R
• I G V
• I C (dv/dt)

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Computer science side
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Axon Experiments
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Few formulas
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Computer science side
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Experiment 1
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Experiment 1 Cont
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Experiment 2
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Reference

• www.ces.clemson.edu
• http//www-2.cs.cmu.edu/dst/HHsim/
• Technion lecture.
• Open University.