The following is a list of experiments from the
book converted into MyFirstNEURON units. In the book conductances and permeabilities
are not density values as in NEURON. Unit conversion factors from the book
to MyFirstNEURON are 1:290 for channel conductances (S/cm2)
and their currents (mA/cm2) and 1:290,000 for permeabilities
(cm/s). Each of the following manipulations is performed independently
using the initial parameters (the red checkboxes restore the initial parameters).
Follow each manipulation by a simulation run.
Experiment
Resting
Potential [1-2]
-
Run
-
Reduce the sodium leak permeability to zero
-
Change the external potassium concentration to 135 mM
-
Reduce the potassium leak permeability to zero
-
Set the potassium leak permeability to 3.45x10-5
cm/s
Membrane
Properties [3-4]
-
Run
-
Change the amplitude of the current clamp to 2 nA
Impulse
Generation [5-6]
-
Run
-
Change the external concentrations of all ions to 0.1 mM, one at a time
-
Set [Na+]o to
0.1 mM and base current to 2.25 nA (4 nA)
-
Set [K+]o to 0.1 mM and base current to 0.8 nA
-
Play with the intracellular potassium concentration
-
Reduce [K+]i to 0.1 mM
-
Keep above change and set base current to -3 nA
Fast
Na+ and K+ Currents: Voltage Clamp [7-9]
-
Run
-
Play with the internal and external concentrations of sodium and potassium,
one at a time
-
Run a voltage clamp series
-
Reduce the maximum conductance of the fast sodium channel to zero and run
the series again
-
Reduce the maximum conductance of the fast potassium channel to zero and
run the series again
Fast
Na+ and K+ Currents: Amplitude & Time Course
[10]
The
A-Current [11]
-
Run
-
Reduce the maximum conductance gk_iA to zero
-
Choose voltage clamp in the Experiments menu and run a voltage clamp
series
-
Change the external potassium concentration to 25 mM and run a voltage
clamp series again
The
L-Current and C-Current [12]
-
Run
-
Reduce the external calcium concentration to 0.01 mM
The
AHP-Current
[13]
-
Run
-
Reduce the maximum conductance gk_iAHP to zero
-
Reduce the external calcium concentration to 0.1 mM
The
T-Current [14]
-
Run
-
Change the base current to 0.18 nA and the initial voltage to -60 mV
-
Reduce the maximum conductance of the fast sodium channel to zero
-
Reduce the external calcium concentration to 0.1 mM
The
M-Current
[15]
-
Run
-
Reduce the maximum conductance gk_iM to zero
-
Reduce the external calcium concentration to 0.1 mM
-
Choose voltage clamp in the Experiments menu and run
-
Play with the extracellular potassium concentration
Excitatory
Postsynaptic Potentials [16]
-
Run
-
Set the IPSP conductances to zero
-
Keep above change and set the base current to 1.78 nA and the initial voltage
to 20 mV
N.M.D.A. current [16]
-
Run
-
Set the base current to -0.52 nA and the initial
voltage to -90 mV
-
Set the base current to 0.525 nA and the initial
voltage to -30 mV
-
Set the base current to -0.52 nA and the initial
voltage to -90 mV and [Mg2+]o to 0.01 mM
-
Set the base current to 0.525 nA and the initial
voltage to -30 mV and [Mg2+]o to 0.01 mM
-
Select NMDA voltage clamp from
the Experiments menu and run a voltage clamp series
-
Repeat the voltage clamp series but now with
[Mg2+]o
=
0.001 mM
-
Perform similar experiments with the AMPA
receptor (switch AMPA and NMDA conductance values)
Inhibitory
Postsynaptic Potentials [17]
-
Run
-
Set the base current to -0.38 nA and the initial
voltage to -85 mV
-
Keep above change and set the external chloride concentration
to 7 mM
-
Set the base current to -0.5 nA and the external
potassium concentration to 25 mM
-
Select IPSP+EPSP from the Experiments menu
and run (keep this selection below)
-
Set the EPSP conductances to zero and the GABAA
conductance to 0.2 nS
-
Change the EPSP conductances back
to 0.15 nS