# vclamp.py ---
#
# Filename: vclamp.py
# Description:
# Author:Subhasis Ray
# Maintainer:
# Created: Sat Feb 2 19:16:54 2013 (+0530)
# Version:
# Last-Updated: Tue Jun 11 17:35:20 2013 (+0530)
# By: subha
# Update #: 178
# URL:
# Keywords:
# Compatibility:
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# Commentary:
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# Change log:
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# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License as
# published by the Free Software Foundation; either version 3, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
# General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; see the file COPYING. If not, write to
# the Free Software Foundation, Inc., 51 Franklin Street, Fifth
# Floor, Boston, MA 02110-1301, USA.
#
#
# Code:
import sys
sys.path.append('../../python')
import moose
sys.path.append('../squid')
from squid import SquidAxon
from pylab import *
def vclamp_demo(simtime=50.0, dt=1e-2):
## It is good practice to modularize test elements inside a
## container
container = moose.Neutral('/vClampDemo')
## Create a compartment with properties of a squid giant axon
comp = SquidAxon('/vClampDemo/axon')
# Create and setup the voltage clamp object
clamp = moose.VClamp('/vClampDemo/vclamp')
## The defaults should work fine
# clamp.mode = 2
# clamp.tau = 10*dt
# clamp.ti = dt
# clamp.td = 0
# clamp.gain = comp.Cm / dt
## Setup command voltage time course
command = moose.PulseGen('/vClampDemo/command')
command.delay[0] = 10.0
command.width[0] = 20.0
command.level[0] = 50.0
command.delay[1] = 1e9
moose.connect(command, 'output', clamp, 'commandIn')
## Connect the Voltage Clamp to the compartemnt
moose.connect(clamp, 'currentOut', comp, 'injectMsg')
moose.connect(comp, 'VmOut', clamp, 'sensedIn')
## setup stimulus recroding - this is the command pulse
stimtab = moose.Table('/vClampDemo/vclamp_command')
moose.connect(stimtab, 'requestOut', command, 'getOutputValue')
## Set up Vm recording
vmtab = moose.Table('/vClampDemo/vclamp_Vm')
moose.connect(vmtab, 'requestOut', comp, 'getVm')
## setup command potential recording - this is the filtered input
## to PID controller
commandtab = moose.Table('/vClampDemo/vclamp_filteredcommand')
moose.connect(commandtab, 'requestOut', clamp, 'getCommand')
## setup current recording
Imtab = moose.Table('/vClampDemo/vclamp_inject')
moose.connect(Imtab, 'requestOut', clamp, 'getCurrent')
# Scheduling
moose.setClock(0, dt)
moose.setClock(1, dt)
moose.setClock(2, dt)
moose.setClock(3, dt)
moose.useClock(0, '%s/##[TYPE=Compartment]' % (container.path), 'init')
moose.useClock(0, '%s/##[TYPE=PulseGen]' % (container.path), 'process')
moose.useClock(1, '%s/##[TYPE=Compartment]' % (container.path), 'process')
moose.useClock(2, '%s/##[TYPE=HHChannel]' % (container.path), 'process')
moose.useClock(2, '%s/##[TYPE=VClamp]' % (container.path), 'process')
moose.useClock(3, '%s/##[TYPE=Table]' % (container.path), 'process')
moose.reinit()
print(('RC filter in VClamp:: tau:', clamp.tau))
print(('PID controller in VClamp:: ti:', clamp.ti, 'td:', clamp.td, 'gain:', clamp.gain))
moose.start(simtime)
print(('Finished simulation for %g seconds' % (simtime)))
tseries = linspace(0, simtime, len(vmtab.vector))
subplot(211)
title('Membrane potential and clamp voltage')
plot(tseries, vmtab.vector, 'g-', label='Vm (mV)')
plot(tseries, commandtab.vector, 'b-', label='Filtered command (mV)')
plot(tseries, stimtab.vector, 'r-', label='Command (mV)')
xlabel('Time (ms)')
ylabel('Voltage (mV)')
legend()
# print len(commandtab.vector)
subplot(212)
title('Current through clamp circuit')
# plot(tseries, stimtab.vector, label='stimulus (uA)')
plot(tseries, Imtab.vector, label='injected current (uA)')
xlabel('Time (ms)')
ylabel('Current (uA)')
legend()
show()
[docs]def main():
"""
This snippet is to demonstrate modelling of voltage clamping.
"""
vclamp_demo()
if __name__ == '__main__':
main()
#
# vclamp.py ends here