// -------------------------------------------------------------- // Initialise user-defined membrane parameters // -------------------------------------------------------------- celsius=37 // nominal temperature of simulation Ri=105 // internal resistivity in ohm-cm Cm=1 // specific membrane capacitance in uF/cm^2 Rm=17000 // specific membrane resistivity in ohm/cm^2 v_init=-75 // resting membrane potential spinescale=2.0 // factor used to membrane area to account for spines // -------------------------------------------------------------------- // Add spines to dend1[881], dend1[876] and dend1[905] // (79, 40 um and 140 um from the soma, respectively) // -------------------------------------------------------------------- access dend1[876] /* dendritic segment with spine */ nseg=20 access dend1[881] /* dendritic segment with spine */ nseg=20 access dend1[905] /* dendritic segment with spine */ nseg=20 create spine_head[3], spine_neck[3] dend1[881] connect spine_neck[0](0), 0.5 spine_neck connect spine_head[0](0), 1 spine_neck[0] {nseg=1 L=1 diam=0.051} // spine neck resistance ~500 MOhm spine_head[0] {nseg=1 L=1 diam=1} dend1[876] connect spine_neck[1](0), 0.5 spine_neck[1] connect spine_head[1](0), 1 spine_neck[1] {nseg=1 L=1 diam=0.1156} // spine neck resistance ~100 MOhm spine_head[1] {nseg=1 L=1 diam=1} dend1[905] connect spine_neck[2](0), 0.5 spine_neck[2] connect spine_head[2](0), 1 spine_neck[2] {nseg=1 L=1 diam=0.1156} // spine neck resistance ~100 MOhm spine_head[2] {nseg=1 L=1 diam=1} // ---------------------------------------------------------------------------- // initialize passive properties and add virtual spines by scaling Rm and Cm //----------------------------------------------------------------------------- forall {insert pas g_pas=1/(Rm/spinescale) cm=Cm*spinescale Ra=Ri e_pas=v_init} // ----------------------------------------------------------------------- // correction for spineless areas: soma, 1st 100 um of apical dendrite, // and 1st 20 um of each basal dendrite //------------------------------------------------------------------------ for i=20,24 { dend1[i] {g_pas=1/Rm cm = Cm} } for i=35,39 { dend1[i] {g_pas=1/Rm cm = Cm} } for i=63,64 { dend1[i] {g_pas=1/Rm cm = Cm} } for i=769,770 { dend1[i] {g_pas=1/Rm cm = Cm} } for i=800,802 { dend1[i] {g_pas=1/Rm cm = Cm} } for i=915,916 { dend1[i] {g_pas=1/Rm cm = Cm} } for i=949,951 { dend1[i] {g_pas=1/Rm cm = Cm} } for i=998,999 { dend1[i] {g_pas=1/Rm cm = Cm} } for i=1047,1050 { dend1[i] {g_pas=1/Rm cm = Cm} } for i=1051,1052 { dend1[i] {g_pas=1/Rm cm = Cm} } for i=1059,1061 { dend1[i] {g_pas=1/Rm cm = Cm} } // ----------------------------------------------------------------------- // correction for spine properties //------------------------------------------------------------------------ for i=0,2 { spine_head[i] {g_pas=1/Rm cm = Cm} spine_neck[i] {g_pas=1/Rm cm = Cm} }