COMMENT Voffset.mod Shifts voltage by the steady state level just before the onset of a current step. This is useful when fitting passive/subthreshold parameters. Implemented by Christina Weaver, 2007 (christina.weaver@mssm.edu) ENDCOMMENT NEURON { SUFFIX offst RANGE Voff, Vshift, Vsum } PARAMETER { Vraise = -58.5 (mV) : how much to shift voltage overall on = 215 (ms) : onset time of current step W = 50 (ms) : length of window to average over we = 10 (ms) : time before step onset to end averaging window didAvg = 0 (1) : flag to minimize computation } UNITS { (mV) = (millivolt) } ASSIGNED { v (millivolt) : t (ms) Vsum (mV) npts (1) Voff (mV) Vshift (mV) } INITIAL { Vsum = 0 Vshift = 0 npts = 0 Voff = v - Voff + Vraise didAvg = 0 : printf("Set npts = %g, Voff %g\n",npts,Voff) } BREAKPOINT { if( t >= on-we-W && t <= on-we ) { Vsum = Vsum + v npts = npts + 1 : printf("time %g\tv %g\tVsum %g\tnpts %g\n",t,v,Vsum,npts) } if( didAvg == 0 && t > on-we ) { : past averaging window didAvg = 1 Voff = Vsum / npts printf("***TIME %g\tFound offset %g = %g / %g\n",t,Voff,Vsum,npts) } Vshift = v - Voff + Vraise : if( t > on-we ) { : printf("SH time %g\tVshift %g = v %g\t- Voff %g\t+ Vraise %g\n",t,Vshift,v,Voff,Vraise) : } }