NEURON Tutorial #17


Goals: Create a kinetic model based on Altomare's model

Specific Aims:

Downloads:


Summary

  Without Ih Ih in Sonia's model Altomare's model
gbar (S/cm2) 0 4e-5 1.1e-5
Time Constant (ms) 30.0 24.3 24.9
Rin (MΩ) 95.5 56.9 66.0
Rebound Slope (mV/mV) 0.00 -0.17 -0.05
Temporal Summation (%) 43.7 11.0 16.9
Depolarizing Resonance Frequency (Hz) 0.6 3.5 2.3
Hyperpolarizing Resonance Frequency (Hz) 1.1 4.5 3.3
Vhalf (mV)   -81.1 -69.0
k (mV)   7.90 9.55

Conclusion: Both models are good.


Steps and Notes:

Create "h_Altomare_2001.mod".
Create "nrnmech.dll".
Start "Main.hoc".

Membrane Time Constant:

Click "Pulse (1 ms)" button.
Click "Initiate & Run" button.
Change "gbar_h" to 1.1e-5 so the resting potential is at -65 mV.
Click "Fit Decay" button.
Tau = 24.9 (ms).

Input Resistance and Rebound Slope:

Click "Current Step (500 ms)" button.
Click "Run Step Family" button.

I & V

Click "Measure Rin (LR)" button.
Rin = 66.0 (M Ohm).

Rin

Click "Measure Rebound Slope (LR)" button.
Rebound Slope = -0.05 (mV/mV).

Temporal Summation:

Click "Five Alpha EPSCs (20 Hz)" button.
Click "Initiate & Run" button.
Click "Measure Temporal Summation" button.
Temporal Summation = 16.9 (%).

Impedance Magnitude Profile and Voltage Lag:

Click "Chirp" button.
Click "Initiate & Run" button.

Chirp

Click "Characterize Chirp Response" button.
Click "Fit Impedance Amplitude" button.

Impedance Magnitude Profile

Depolarizing Resonance Frequency = 2.3 (Hz)
Hyperpolarizing Resonance Frequency = 3.3 (Hz)

Click "Plot Voltage Lag" button.

Voltage Delay

G-V Curve and Tau-V Curve

Click "Voltage Clamp" button.
Click "Run Activation Step Family" button.
Click "Fit GV Curve" button.

GV Curve

vhalf = -69.0 (mV)
k = 9.55 (mV)

Click "Run Deactivation Step Family" button.
Click "Plot Tau" button.

Time Constant