//genesis // kAf_chanRE.g /*************************** MS Model, Version 7.6 ********************* **************************** kAf_chanRE.g ********************* Avrama Blackwell kblackw1@gmu.edu Rebekah Evans rcolema2@gmu.edu Tom Sheehan tsheeha2@gmu.edu ****************************************************************************** *****************************************************************************/ function make_KAf_channel //include tabchanforms //initial parameters for making tab channel float Erev = -0.09 int m_power = 2 int h_power = 1 //Activation constants for alphas and betas (obtained by matching Tkatch 2000) //units are mV, ms float mA_rate = 1.5 float mA_vhalf = 4 float mA_slope = -17 float mB_rate = 0.6 float mB_vhalf = 10 float mB_slope = 9 //Inactivation constants for alphas and betas //units are mV, ms float hA_rate = 0.105 float hA_vhalf = -121 float hA_slope = 22 float hB_rate = 0.065 float hB_vhalf = -55 float hB_slope = -11 //table filling parameters float xmin = -0.1 /* minimum voltage we will see in the simulation */ float xmax = 0.05 /* maximum voltage we will see in the simulation */ int xdivsFiner = 3000 int c = 0 float increment =1000*{{xmax}-{xmin}}/{xdivsFiner} // echo "kAf: inc="{increment}"mV" float x = -100 /* make the table for the activation with a range of -100mV - +50mV * with an entry for every 10mV */ str path = "KAf_channel" create tabchannel {path} call {path} TABCREATE X {xdivsFiner} {xmin} {xmax} call {path} TABCREATE Y {xdivsFiner} {xmin} {xmax} /*fills the tabchannel with values for minf, mtau, hinf and htau, *from the files. */ echo "make kAf, qfactor=" {qfactorkAf} for (c = 0; c < {xdivsFiner} + 1; c = c + 1) float m_alpha = {sig_form {mA_rate} {mA_vhalf} {mA_slope} {x}} float m_beta = {sig_form {mB_rate} {mB_vhalf} {mB_slope} {x}} float h_alpha = {sig_form {hA_rate} {hA_vhalf} {hA_slope} {x}} float h_beta = {sig_form {hB_rate} {hB_vhalf} {hB_slope} {x}} /* 1e-3 converts from ms to sec */ setfield {path} X_A->table[{c}] {{qfactorkAf}*{1e-3/(m_alpha+m_beta)}} setfield {path} X_B->table[{c}] {m_alpha/(m_alpha+m_beta)} setfield {path} Y_A->table[{c}] {{1e-3/(h_alpha+h_beta)}/{qfactorkAf}} setfield {path} Y_B->table[{c}] {h_alpha/(h_alpha+h_beta)} x = x + increment end /* Defines the powers of m and h in the Hodgkin-Huxley equation*/ setfield {path} Ek {Erev} Xpower {m_power} Ypower {h_power} tweaktau {path} X tweaktau {path} Y end