//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
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