: simple first-order model of calcium dynamics
: from Durstewitz & Gabriel (2006), Cerebral Cortex
NEURON {
SUFFIX cadyn
USEION ca READ cai, ica WRITE cai
RANGE CAF, tc, cai
}
UNITS {
(mM) = (milli/liter)
(mA) = (milliamp)
F = (faraday) (coul)
}
PARAMETER {
tc= 70 (ms) : decay time constant
cainf= 50e-6 (mM) : (50e-6)equilibrium ca2+ concentration
dep= 2e-4 (micron) : depth of shell for ca2+ diffusion
}
ASSIGNED {
ica (mA/cm2)
diam (micron)
A (/coul/cm)
CAF ()
}
INITIAL {
A =(1e4)/(F*dep)
cai=cainf
}
STATE { cai (mM) }
BREAKPOINT {
SOLVE states METHOD derivimplicit
}
DERIVATIVE states {
cai'= -A*CAF*ica - (cai-cainf)/tc
}