GABA_BResponse.cpp

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#include "GABA_BResponse.h"

GABA_BResponse::GABA_BResponse()
{
        k1    = 9.0*10e4;    // [M^-1 s^-1]
    k2    = 1.2;         // [s^-1]
    k3    = 180.0;       // [s^-1]
    k4    = 34.0;        // [s^-1]

    kd    = 100.0; 
    dead_time = 1e-3;
    Cdur    = 0.3e-3;
    Cmax    = 0.5;
    n     = 4;
    
    g_max = 1.0;
}

int GABA_BResponse::reset( double dt )
{
        r=0.0;
        s=0.0;
        
    time_count = -dead_time-dt;

    double A=k1*Cmax;
    double B_on=k1*Cmax+k2;
    double B_off=k2;
        
    C1_on=exp(-B_on*dt);
    C1_off=exp(-B_off*dt);
    C2_on=A/B_on*(1-C1_on);

    C3=exp(-k4*dt);
    C4=1/k4*(1-C3);

    return FiniteSpikeResponse::reset(dt);
}


int GABA_BResponse::advance(AdvanceInfo const &ai)
{       
        time_count -= ai.dt.in_sec();

        if(time_count > 0.0)
        r = r*C1_on + C2_on;                    
        else 
        r = r*C1_off;
                                
    s = s*C3 + k3*r*C4;
                
    psr = g_max / ( 1.0 + kd / pow(s, n) );
       
    return advanceReturn();
}

int GABA_BResponse::spikeHit( spikeport_t port, SpikeEvent const& spike )
{
        if( port == 0 ) {
        if(time_count < -dead_time)     {
                time_count = Cdur;
//                      g_max=spike.weight;
        }
        else {
                cerr << "spike missed" << endl;
        }
    }
    
    return spikeHitReturn( AdvanceInfo( spike.dt ) );
}

int GABA_BResponse::psrLength(double dt) const
{
        // TODO: replace this simple approximation      
    const double tau = 0.200;   
    return (int)( (double)PSR_MULTIPLE_TAU * tau / dt + 0.5 );
}










// Nest style


GABA_BResponseNest::GABA_BResponseNest()
{
        k1    = 9.0*10e4;    // [M^-1 s^-1]
    k2    = 1.2;         // [s^-1]
    k3    = 180.0;       // [s^-1]
    k4    = 34.0;        // [s^-1]

    kd    = 100.0;
    pulse = 1.105*10e-3; // [s]
    T     = 1e-3;        // [M]
    n     = 4;
}

int GABA_BResponseNest::reset( double dt )
{
    r=0.0;
    s=0.0;

    // The exact integration matrix
    exp_A00 = exp(-dt*k2);
    exp_A10 = (exp(-dt*k2)-exp(-dt*k4)) / (k4 - k2);
    exp_A11 = exp(-dt*k4);


    double tau_r_add = 1 / (k1*T + k2);

    r_inf = k1* k3* T* tau_r_add;
    exp_r_add = 1 - exp(-pulse / tau_r_add);

    return FiniteSpikeResponse::reset(dt);
}

int GABA_BResponseNest::advance(AdvanceInfo const &ai)
{
    // The exact integration step
    s = exp_A10 * r + exp_A11 * s;
    r = exp_A00 * r;

    psr =  g_max / ( 1.0 + kd / pow(s, n) );
    
    return advanceReturn();
}

int GABA_BResponseNest::spikeHit( spikeport_t port, SpikeEvent const& spike )
{
    if( port == 0 ) {
        r += (r_inf - r)*exp_r_add;
//              g_max=spike.weight;
    }

    return spikeHitReturn( AdvanceInfo( spike.dt ) );
}


int GABA_BResponseNest::psrLength(double dt) const
{
        // TODO: replace this simple approximation      
        const double tau = 0.200;   
        return (int)( (double)PSR_MULTIPLE_TAU * tau / dt + 0.5 );
}

/*
// nest type

k1    = 90.0,     // M/ms
k2    = 0.0012,   // 1/ms
k3    = 0.18,     // 1/ms
k4    = 0.034,    // 1/ms
kd    = 100,
T     = 1e-3,     // M
pulse = 1.105,    //ms The pulse length (adjusted)

    virtual int reset( double dt )
    {
        r=0.0;
        s=0.0;

        double _dt = dt*10e3;

        // The exact integration matrix
        exp_A00 = exp(-_dt*k2);
        exp_A10 = (exp(-_dt*k2)-exp(-_dt*k4)) / (k4 - k2);
        exp_A11 = exp(-_dt*k4);

        double tau_r_add = 1 / (k1*T + k2);

        r_inf = k1* k3* T* tau_r_add;
        exp_r_add = 1 - exp(-pulse / tau_r_add);

        return FiniteSpikeResponse::reset(dt);
    }

*/

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