//genesis float PI = 3.14159 // ===================================================================== // PHYSIOLOGICAL PARAMETERS // ===================================================================== // All units in SI and usually dimensions are given as well // IONIC EQUILIBRIUM POTENTIALS // V float ENA = 55e-3 // V float ECA = 70 - 3 // V float ECL = -65e-3 // V float EK = -90e-3 // V float EREST = -70e-3 // V float I_EREST = -70e-3 // ACTIVE COMPARTMENT POTENTIALS // V float EREST_ACT = -70e-3 // V float ENA_ACT = 115.0e-3 + EREST_ACT // V float ECA_ACT = 140.0e-3 + EREST_ACT // V float EK_ACT = -12.0e-3 + EREST_ACT // V float ELEAK_ACT = 10.6e-3 + EREST_ACT // squid giant axon - Conti et al.(1975),J.Physiol(Lond),248,45-82 // gNa = 4pS // squid giant axon - Conti and Neher(1980),Nature(Lond),285,140-143 // gK = 18pS // mouse spinal neurone - Mathers and Barker(1982),Int.Rev.Neurobiol,23,1-34 // gCl = 18pS // UNIT CONDUCTANCES // (Siemens/channel) // S float UNIT_GNA = 12e-12 // S float UNIT_GCL = 18e-12 // S float UNIT_GK = 4e-12 // S float SUNIT_GNA = 8e-12 // S float SUNIT_GK = 4e-12 // squid giant axon - Conti et al.(1975),J.Physiol(Lond),248,45-82 // rhoNa = 330 channels/um^2 // squid giant axon - Conti and Neher(1980),Nature(Lond),285,140-143 // rhoK = 72 channels/um^2 // CHANNEL DENSITIES // (channels/m^2) float RHO_NA = 60e12 float RHO_CL = 30e12 float RHO_K = 30e12 float SRHO_NA = 330e12 float SRHO_K = 72e12 float IRHO_NA = 10e12 // SYNAPTIC AREA // Haberly and Presto(1986),J.Comp.Neurol,248,464-474 // basal spine d = .40um // distal spine d = .74um // presynaptic to dendritic spines d = .61 // presynaptic to dendritic shafts d = .89 // presynaptic to initial segment d = .89 // using synaptic contact area A = pi*d^2/4 // (m^2/synapse) float ASYN_LOCAL_NA = 0.12e-12 float ASYN_DISTAL_NA = 0.43e-12 float ASYN_CL = 0.62e-12 float ASYN_K = 0.43e-12 float IASYN_NA = 0.29e-12 // ACTIVE AREA // fraction of somatic area containing active channels float fAC = 0.1 // PEAK CONDUCTANCE // (Siemens/synapse) float I_GMAX_NA = UNIT_GNA*IRHO_NA*IASYN_NA float LOCAL_GMAX_NA = UNIT_GNA*RHO_NA*ASYN_LOCAL_NA float DISTAL_GMAX_NA = UNIT_GNA*RHO_NA*ASYN_DISTAL_NA float GMAX_K = UNIT_GK*RHO_K*ASYN_K float GMAX_CL = UNIT_GCL*RHO_CL*ASYN_CL // S/m^2 float SGMAX_NA = SUNIT_GNA*SRHO_NA // S/m^2 float SGMAX_K = SUNIT_GK*SRHO_K // MEMBRANE PARAMETERS // ohm-m^2 float RM = 0.2 // ohm-m float RA = 0.5 // F/m^2 float CM = 0.01 // TYPICAL CELL DIMENSIONS // m float SOMA_D = 20.0e-6 // m float SOMA_L = 20.0e-6 // m^2 float SOMA_A = PI*SOMA_D*SOMA_L // m^2 float SOMA_XA = PI*SOMA_D*SOMA_D/4 // m float DEND_D = 1.5e-6 // m float DEND_L = 100.0e-6 // m^2 float DEND_A = PI*DEND_D*DEND_L // m^2 float DEND_XA = PI*DEND_D*DEND_D/4 /* ** VARIABLES USED BY ACTIVE COMPONENTS */ int EXPONENTIAL = 1 int SIGMOID = 2 int LINOID = 3 // sec float SYNDELAY = 0.8e-3 // sec float FFDELAY = 5e-3 /* ** CALCIUM DIFFUSION PARAMETERS */ // Molar float BASE_CA_CONC = 0.1e-6 // Range is 0.3 uM to 0.02 uM // m/sec as a very rough est float CA_DIFF = 5e-6