NEURON Tutorial #16

Goals: Examine the kinetic scheme (C <-> O)2

Specific Aims:



  Ih in Sonia's model Kinetic Scheme
gbar (S/cm2) 4e-5 3.7e-5
Time Constant (ms) 24.3 23.4
Rin (MΩ) 56.9 53.3
Rebound Slope (mV/mV) -0.17 -0.15
Temporal Summation (%) 11.0 7.5
Depolarizing Resonance Frequency (Hz) 3.5 3.5
Hyperpolarizing Resonance Frequency (Hz) 4.5 5.2
Vhalf (mV) -81.1 -79.7
k (mV) 7.90 8.54

Conclusion: Both models are good.

Steps and Notes:

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

Membrane Time Constant:

Click "Pulse (1 ms)" button.
Click "Initiate & Run" button.
Change "gbar_h" to 3.73e-5 so the resting potential is at -65 mV.
Click "Fit Decay" button. Tau = 24.3 (ms).

Input Resistance and Rebound Slope:

Click "Current Step (500 ms)" button.
Click "Run Step Family" button.
Click "Measure Rin (LR)" button. Rin = 53.3 (M Ohm).
Click "Measure Rebound Slope (LR)" button. Rebound Slope = -0.15 (mV/mV).

Temporal Summation:

Click "Five Alpha EPSCs (20 Hz)" button.
Click "Initiate & Run" button.
Click "Measure Temporal Summation" button.
Temporal Summation = 7.5 (%).

Impedance Magnitude Profile and Voltage Lag:

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


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

Impedance Magnitude Profile

Depolarizing Resonance Frequency = 3.5 (Hz)
Hyperpolarizing Resonance Frequency = 5.2 (Hz)

Click "Plot Voltage Lag" button.

Voltage Lag

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 = -79.7 (mV)
k = 8.54 (mV)

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