auryn::LinearComboSynapse Class Reference

Implements Auryn's default conductance based AMPA, Combo synapse without Combo voltage dependence. More...

#include <LinearComboSynapse.h>

Inheritance diagram for auryn::LinearComboSynapse:

Collaboration diagram for auryn::LinearComboSynapse:

Public Member Functions
	LinearComboSynapse (NeuronGroup *parent, AurynStateVector *input, AurynStateVector *output)
virtual	~LinearComboSynapse ()
void	set_tau_ampa (const AurynState tau)
	Sets AMPA decay time scale. More...
void	set_tau_nmda (const AurynState tau)
	Sets Combo decay time scale. More...
void	set_e_rev (const AurynState reversal_pot)
	Sets reversal potential. More...
void	set_ampa_nmda_ratio (AurynFloat ratio)
	Set ratio between ampa/nmda contribution to excitatory conductance. More...
void	set_nmda_ampa_current_ampl_ratio (AurynFloat ratio)
	Sets nmda-ampa amplitude ratio. More...
void	clear ()
virtual void	evolve ()
Public Member Functions inherited from auryn::SynapseModel
	SynapseModel (NeuronGroup *parent, AurynStateVector *input, AurynStateVector *output)

Additional Inherited Members
Protected Attributes inherited from auryn::SynapseModel
NeuronGroup *	parent_group
AurynStateVector *	input_state
AurynStateVector *	output_state

Detailed Description

Implements Auryn's default conductance based AMPA, Combo synapse without Combo voltage dependence.

Default timescales are tau_ampa = 5e-3 and tau_nmda = 100e-3.

Constructor & Destructor Documentation

LinearComboSynapse()

LinearComboSynapse::LinearComboSynapse	(	NeuronGroup *	parent,
		AurynStateVector *	input,
		AurynStateVector *	output
	)

        : SynapseModel( parent, input, output )
{
        if ( input == output ) {
                logger->warning("LinearComboSynapse requires input and output state to be different!");
        }

        set_tau_ampa(5e-3); // sets a default timescale
        set_tau_nmda(100e-3); // sets a default timescale
        set_e_rev(0.0); // sets default reversal potential

        g_ampa = input_state;
        g_nmda = parent_group->get_state_vector("g_nmda");
        temp   = parent_group->get_state_vector("_temp");

        set_ampa_nmda_ratio(1.0);
}

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~LinearComboSynapse()

LinearComboSynapse::~LinearComboSynapse ( )

virtual

{
}

Member Function Documentation

clear()

void auryn::LinearComboSynapse::clear

(

)

evolve()

void LinearComboSynapse::evolve ( )

virtual

Implements auryn::SynapseModel.

{
        temp->diff(e_rev, parent_group->mem);

        output_state->set_all(0.0);
        output_state->saxpy(A_ampa,g_ampa);
        output_state->saxpy(A_nmda,g_nmda);
        output_state->mul(temp);

        g_nmda->saxpy(-mul_nmda, g_nmda);
        g_nmda->saxpy(mul_nmda, g_ampa);
        g_ampa->scale(scale_ampa);
}

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set_ampa_nmda_ratio()

void LinearComboSynapse::set_ampa_nmda_ratio

(

AurynFloat

ratio

)

Set ratio between ampa/nmda contribution to excitatory conductance.

This sets the ratio between the integrals between the conductance kernels.

{
        A_ampa = ratio/(ratio+1.0);
        A_nmda = 1./(ratio+1.0);
}

set_e_rev()

void LinearComboSynapse::set_e_rev

(

const AurynState

reversal_pot

)

Sets reversal potential.

{
        e_rev = reversal_pot;
}

set_nmda_ampa_current_ampl_ratio()

void LinearComboSynapse::set_nmda_ampa_current_ampl_ratio

(

AurynFloat

ratio

)

Sets nmda-ampa amplitude ratio.

This sets the ratio between the amplitudes of nmda to ampa.

{
        const double tau_r = tau_ampa;
        const double tau_d = tau_nmda;

        // compute amplitude of Combo conductance
        const double tmax = tau_r*std::log((tau_r+tau_d)/tau_r); // argmax
        const double ampl = (1.0-std::exp(-tmax/tau_r))*std::exp(-tmax/tau_d)*tau_r/(tau_d-tau_r); 

        // set relative amplitudes
        A_ampa = 1.0;
        A_nmda = ratio/ampl;

        // normalize sum to one
        const double sum = A_ampa+A_nmda;
        A_ampa /= sum;
        A_nmda /= sum;

        // write constants to logfile
        logger->parameter("A_ampa", A_ampa);
        logger->parameter("A_nmda", A_nmda);
}

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set_tau_ampa()

void LinearComboSynapse::set_tau_ampa

(

const AurynState

tau

)

Sets AMPA decay time scale.

{
        tau_ampa = tau;
        scale_ampa = std::exp(-auryn_timestep/tau_ampa);
}

set_tau_nmda()

void LinearComboSynapse::set_tau_nmda

(

const AurynState

tau

)

Sets Combo decay time scale.

{
        tau_nmda = tau;
        mul_nmda   = 1.0-std::exp(-auryn_timestep/tau_nmda);
}

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The documentation for this class was generated from the following files:

• /home/zenke/auryn/src/auryn/LinearComboSynapse.h
• /home/zenke/auryn/src/auryn/LinearComboSynapse.cpp