TITLE Calcium dynamics for RD Traub, J Neurophysiol 89:909-921, 2003 COMMENT Implemented by Maciej Lazarewicz 2003 (mlazarew@seas.upenn.edu) ENDCOMMENT NEURON { SUFFIX cad USEION ca READ ica WRITE cai RANGE phi, beta GLOBAL ceiling } UNITS { (mA) = (milliamp) } PARAMETER { phi (1) beta (/ms) ceiling (1) } STATE { cai (1) } INITIAL { cai = 0.0 } ASSIGNED { ica (mA/cm2) } BREAKPOINT { SOLVE state METHOD cnexp if( cai < 0 ){ cai = 0 } if( cai > ceiling ){ cai = ceiling } } DERIVATIVE state { cai' = - phi * ica - beta * cai }