//genesis //nmda_channel.g function make_NMDA_channel (chanpath, Ek, KMg, tau2, gmax, ghk, depr, deprtau) str chanpath //what you want the channel to be called (full path) float KMg, tau2, gmax //parameters that differ between NR2A, B, C and D subunits float depr float deprtau float Ek int ghk float tau1 = (4.4624e-3)/2 //(5.63e-3)/8 //(4.4624e-3)/2 // DE Chapman et al 2003, table 1 (5.63ms: wolf) w/qfact of 2 //is (4.4624e-3)/2 in Evans et al., 2012 float CMg = 1.4 // [Mg] in mM //Kerr and Plenz uses 1.4mM Mg float eta = 1/18 // Kmg = 1/eta, (per mM) overwritten by synparams, 3.57 old, 18 new float gamma = 99 //99 new //62 old // per Volt echo "XXXXXXXXXXXXXXX make_NMDA_channel XXXXXXXXXXXXXXXX" echo "chanpath = "{chanpath} echo "caBuffer = "{Ek} echo "KMg = "{KMg} echo "tau2 = "{tau2} echo "gmax = "{gmax} echo "XXXXXXXXXXXXXXX make_NMDA_channel XXXXXXXXXXXXXXXX" create facsynchan {chanpath} setfield {chanpath} \ Ek {Ek} \ tau1 {tau1} \ tau2 {tau2} \ gmax {gmax} \ depr_per_spike {depr}\ depr_tau {deprtau} //why was this gmax/2?? changed back 4/15/12 RCE is overwritten by addNMDAchannel function, so I don't think it matters. //the kinetics of the magnesium block is different for different subunits. // NR2A and B are about the same, but C and D are much less affected by the block. //these numbers were used because the made the magnesium block curve fit the figures by Moyner et al (1994 figure 7) best by eye. create Mg_block {chanpath}/block setfield {chanpath}/block CMg {CMg} setfield {chanpath}/block KMg_B {1.0/{gamma}} setfield {chanpath}/block KMg_A {KMg} addmsg {chanpath} {chanpath}/block CHANNEL Gk Ek if (ghk==1) //GHK_yesno is set in Synparams.g create ghk {chanpath}/GHK setfield {chanpath}/GHK Cout 2 // Carter & Sabatini 2004 uses 2mM, Wolf 5mM setfield {chanpath}/GHK valency 2.0 setfield {chanpath}/GHK T {TEMPERATURE} addmsg {chanpath}/block {chanpath}/GHK PERMEABILITY Gk end end