/*
* Prints to stdout a table containing the voltage at all points in a
* dendritic tree, after 10 ms of simulation in response to a recorded somatic
* action potential.
*
* globals:
* voltage_vec
* time_vec
* which_secs
*
* Arguments:
* $o1: soma > A SectionRef pointing to the soma.
* $o2: voltage_vec > A vector containing an experimentally measured somatic
* action potential.
* $o3: time_vec > A vector containing the time points for voltage_vec
* $s4: which_secs > A regular expression that specifies all the dendritic
* sections over which the function should iterate.
*
*/
objref graphs
proc BAPvalues() { local real_diam, real_L, rt, rtstart, ts localobj voltage_vec, time_vec, distances, voltages,\
output_matrix, soma
soma = $o1
soma.sec {
nseg = 1
real_diam = diam(0.5)
real_L = L
diam = 2.0 * STD_SOMA
L = 2.0 * STD_SOMA
}
voltage_vec = $o2
time_vec = $o3
strdef which_secs
which_secs = $s4
access soma.sec
// Set up the attenuation values by playing an action potential into the
// soma for ten seconds. The action potential itself only lasts 2.
v_init = E_PAS
finitialize(v_init)
tstop = 10
dt = 0.025
// voltage_vec.play(&soma.sec.v(0.5), time_vec)
voltage_vec.play(&soma.sec.v(0.5), .025)
run()
distances = new Vector()
voltages = new Vector()
// Iterate over the dendritic tree.
forsec which_secs {
for(x) {
distances.append(distance_origlen(x))
voltages.append(val_max(x)  v_init) // Assumes the "max" mechanism is
// installed in the neuron.
}
}
// Output the data
output_matrix = new Matrix(voltages.size(), 2)
output_matrix.setcol(0, distances)
output_matrix.setcol(1, voltages)
output_matrix.printf("%f\t")
soma.sec {
diam = real_diam
L = real_L
}
}
/*
* Calculates the steadystate voltage in response to current steps of
* ranging from 120 pA to 80 pA, in 20 pA increments, for a duration of 200
* ms each. These should fall along a line, the slope of which is the input
* resistance. The values are printed in a single line, tabdelimited.
*
* $o1: a SectionRef pointing to the section into which the current should
* be injected.
*/
proc inputResistance() { local equilibrium_value, i localobj stim, stim_target
$o1.sec stim_target = new SectionRef()
tstop = 200
dt = 0.025
// This is broken: it shouldn't depend on whatever the first clamp object is.
// Force a crash to make sure it's not being used.
print "In broken function!"
print 0/0
stim_target.sec { stim = new IClamp(0) }
stim.del = 0
stim.dur = 200
for (i = .120; i <= 0.080; i += 0.02) {
v_init = E_PAS
stim.amp = i
finitialize(v_init)
run()
equilibrium_value = stim_target.sec.v(0.5)
printf("%f\t", equilibrium_value)
}
}
