// --------------------------------------------------------------
// 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}
}