NEURON Tutorial #14


Goals: Test kinetic scheme created by Payne and compare the result with Sonia's Ih result

Specific Aims:

Downloads:


Summary

  Ih in Sonia's model Payne's kinetic model
gbar (S/cm2) 4e-5 5e-5
Time Constant (ms) 24.3 24.3
Rin (MΩ) 56.9 54.9
Rebound Slope (mV/mV) -0.17 -0.21
Temporal Summation (%) 11.0 9.25
Depolarizing Resonance Frequency (Hz) 3.5 3.8
Hyperpolarizing Resonance Frequency (Hz) 4.5 4.7
Vhalf (mV) -81.1 -81.4
k (mV) 7.90 7.42
Time for Chirp Simulation (sec) 28.55 29.54

Conclusion: Both models are good.


Steps and Notes:

Start "Main.hoc".

   

Measure membrane time constant:embrane time constant:

  • Click "Pulse (1 ms)" button.
  • Click "Initiate & Run" button.
  • Adjust gbar_h to 5e-5 so the resting membrane potential is -65 mV.
  • Click "Initiate & Run" button.
  • Click "Fit Decay" button.
Voltage and Current Traces
Time constant = 24.3 (ms)
Time Constant
 

Measure Rin and Rebound Slope:

  • Click "Current Step (500 ms)" button.
  • Click "Run Step Family" button.
  • Click "Measure Rin (LR)" button.
  • Click "Measure Rebound Slope (LR)" button.
Voltage and Current Traces:
Current Step Family
Rin = 54.9 (M Ohm)
Rin

Rebound Slope = -0.21 (mV/mV)
Rebound Slope

Temporal Summation:

  • Click "Five Alpha EPSCs (20 Hz)" button.
  • Click "Initiate & Run" button.
  • Click "Measure Temporal Summation" button.
Temporal Summation = 9.25 (%)
Temporal Summation
 

Chirp Experiment:

  • Click "Chirp" button.
  • Click "Initiate & Run" button.
  • Click "Characterize Chirp Response" button.
  • Click "Fit Impedance Amplitude" button.
  • Click "Plot Voltage Lag"
Voltage and Current Traces:
Chirp
Impedance Amplitude:
Depolarizing Resonance Frequency = 3.8 (Hz)
Hyperpolarizing Resonance Frequency = 4.7 (Hz)
Impedance Magnitude

Voltage Lag:
Voltage lag

Voltage Clamp Experiment:

  • Click "Voltage Clamp" button.
  • Click "Run Activation Step Family" button.
  • Click "Fit GV Curve" button.
Voltage and Current Traces:
Voltage Clamp Experiment
GV Curve:
Vhalf = -81.4 (mV)
k = 7.42 (mV)
GV Curve
  • Click "Run Deactivation Step Family" button.
  • Click "Plot Tau" button.
Voltage and Current Traces:
Deactivation
Tau:
Time Constant