class implementing a simple integrate-and-fire neuron More...

Inheritance diagram for IfNeuron:

Public Member Functions
	IfNeuron (Time *time, double v0, double theta, double spikeheight, double tau, double v_rest, const string &name="", const string &type="Integrate-and-Fire Neuron")
	Construct. More...

	~IfNeuron ()
	destruct

void	calibrate (int isi, int runs, int maxtime, NoiseSource *noises=0, double increment=1.1, double decrement=0.8)
	Calibrate the neuron. More...

virtual string	getParameter (const string &name) const
	Get parameter. More...

virtual void	setParameter (const string &name, const string &value)
	Set parameter. More...

int	addStimulus (StochasticVariable *integrator)
	add a stimulus More...

int	addStimulus (StochasticVariable *integrator, double weight)
	add a stimulus More...

int	addStimulus (StochasticVariable *integrator, double weight, double revpot)
	add a stimulus More...

virtual int	addStimulus (Synapse *synapse)
	Add a synapse. More...

virtual void	removeStimulus (int n)
	Remove a stimulus. More...

virtual bool	hasEvent ()
	Return whether a spike is happening.

virtual uint	getEventAmount ()
	Retrun the amount of current events.

virtual void	setNextValue (double d)
	Set the next value of the process. More...

virtual void	setCurrentValue (double d)
	Set the current value of the process. More...

virtual void	prepareNextState ()
	step

virtual void	proceedToNextState ()
	Proceed one time step. More...

Public Member Functions inherited from StochasticEventGenerator
	StochasticEventGenerator (class Time *time, const string &name="", const string &type="Event Generator")
	Create.

virtual	~StochasticEventGenerator ()
	Destroy.

Public Member Functions inherited from StochasticVariable
	StochasticVariable (class Time *time, const string &name="", const string &type="Stochastic Variable")
	Create.

double	operator() ()
	Returns the value at the current time step. More...

double	d ()
	Returns the increment at the current time step. More...

Public Member Functions inherited from StochasticProcess
	StochasticProcess (class Time *time, const string &name="", const string &type="Stochastic")
	Create.

virtual	~StochasticProcess ()
	Destroy.

bool	isNextStatePrepared ()
	Whether.

virtual double	getIncrement ()
	Returns the increment. More...

virtual double	getCurrentValue ()
	Returns the value of the process. More...

virtual double	getNextValue ()
	Returns the next value of the process. More...

void	setDescription (string s)
	Set stochastic description.

virtual void	init ()
	Initialise time-dependent values.

string	getDescription ()
	Get the name. More...

Public Member Functions inherited from Parametric
string	getType () const
	Type of object.

string	getName () const
	Name of object.

void	setName (const string &name)
	Name of object.

string	getConfiguration () const
	Returns the configuration of the object. More...

string	getAllParameters () const
	String with all parameter settings.

void	addParameter (const string &name)
	Add a parameter. More...

void	rmParameter (const string &name)
	Remove a parameter. More...

Public Member Functions inherited from TimeDependent
	TimeDependent (class Time *time)
	Construct. More...

virtual class Time *	getTime () const
	Return pointer to the time object.

Public Member Functions inherited from Physical
	Physical ()
	Construct.

	Physical (const Physical &)
	Copy.

	Physical (string name)
	Construct.

	Physical (string name, string unitPrefix, string unitSymbol)
	Construct.

	Physical (string name, Unit unit)
	Construct.

virtual string	getPhysicalDescription ()
	Returns the physical description. More...

virtual string	getUnitName ()
	Returns the unit name.

virtual string	getUnitSymbol ()
	Returns the unit name.

virtual void	setPhysicalDescription (string name)
	Set the name. Same as setDescription(). More...

virtual void	setUnit (Unit u)
	Set the unit.

virtual void	setUnitPrefix (int n)
	Set unit prefix. More...

virtual Unit	getUnit () const
	Retrieve the unit.

Additional Inherited Members
Protected Member Functions inherited from SpikingNeuron
	SpikingNeuron (Time *time, string name, string type="Spiking Neuron")
	Construct. More...

Protected Member Functions inherited from Neuron
	Neuron (string name, string type)
	Construct. More...

Protected Member Functions inherited from Parametric
	Parametric (const string &name, const string &type)
	Create object of type and name.

virtual	~Parametric ()
	Destroy object.

Protected Attributes inherited from StochasticProcess
double	stochCurrentValue
	the current value

double	stochNextValue
	the next value (direct future)

bool	stochNextStateIsPrepared
	whether prepareNextState() was successful

string	stochDescription
	the name of the quantity

Detailed Description

class implementing a simple integrate-and-fire neuron

This class implements an integrate-and-fire neuron. The neuron can be used with conductances, synapses or simple stochastic input. Ito and Stratonovitch integrals may be used (use setIto() or setStratonovich() from DifferentialEquation), and can be used as a trigger for ConditionalEstimator. The function is

$dV_t = \frac{1}{C} (v_L - V_t) g_L dt + \sum_i \frac{1}{C} w_i (v_i - V_t) dG^i_t$

when conductances are used, or

$dV_t = \frac{1}{C} (v_L - V_t) g_L dt + \frac{1}{C} w dG^i_t$

when currents are used. $ V_t $ is the membrane voltage, $ C $ is the membrane capacity which is always set to $1 \mu F$ , $ v_L $ is the leak reversal potential, $ g_L $ is the leak conductance. $ w_i, v_i, dG^i $ are weight, reversal potential and conductance of a stimulating synapse.

Constructor & Destructor Documentation

IfNeuron::IfNeuron	(	Time *	time,
		double	v0,
		double	theta,
		double	spikeheight,
		double	tau,
		double	v_rest,
		const string &	name = `""`,
		const string &	type = `"Integrate-and-Fire Neuron"`
	)

Construct.

Default constructor only to be used by derived classes. construct Creates a neuron.

Parameters

time	Address of global ime object
v0	Reset potential
theta	Threshold potential
spikeheight	Hight of a spike in mV
tau	Membrane time constant
v_rest	Resting potential
name	name of object
type	type of object, only use this when calling from a deriving class

Member Function Documentation

int IfNeuron::addStimulus ( StochasticVariable * integrator )

add a stimulus

This adds a stimulus without a reversal potential, i.e. the value is added purely onto the membrane potential. The variable must have the unit mA * ms.

int IfNeuron::addStimulus	(	StochasticVariable *	integrator,
		double	weight
	)

add a stimulus

This adds a stimulus without a reversal potential, but the value is multiplied by the given weight before being added onto the membrane potential. The weight must be a dimensionless scalar, and the integrator must have the unit mA ** ms.

int IfNeuron::addStimulus	(	StochasticVariable *	integrator,
		double	weight,
		double	revpot
	)

add a stimulus

This adds a stimulus with a reversal potential. The value is multiplied by the given weight and by the distance of the voltage from the reversal potential before being added onto the membrane potential.

virtual int IfNeuron::addStimulus ( Synapse * synapse )

virtual

Add a synapse.

Parameters

synapse The synapse to be added.

Returns: The index of the integrator/integrand added. Use this number if you want to remove the synapse again. This adds a stimulus which is a synapse. The synapse should have the unit mV * mS.

Implements Neuron.

void IfNeuron::calibrate	(	int	isi,
		int	runs,
		int	maxtime,
		NoiseSource *	noises = `0`,
		double	increment = `1.1`,
		double	decrement = `0.8`
	)

Calibrate the neuron.

Set the neuron to a specific reponse rate. This is achieved by internally adjusting the threshold. If you do not give a NoiseSource object, all inputs to the neuron must be active for this to work. If the neuron receives passive processes (like correlated noise from a NoiseSource), you must give the address of the NoiseSource object driving them.

Parameters

isi	Desired inter-spike interval, given in time steps.
runs	Number of runs used to estimate threshold. 50 is a good compromise.
maxtime	Maximum time for one run to take. 10*isi is a good compromise
noises	Address of a NoiseSource object.
increment	factor used for increasing step size when direction is kept
decrement	factor used for decreasing step size when direction is changed

virtual string IfNeuron::getParameter ( const string & name ) const

virtual

Get parameter.

In a derived class, override this to handle every parameter you implement. If a parameter is described using multiple strings separated by space, this indicates a parameter of a parameter.

Parameters

name	name of parameter

Reimplemented from Parametric.

virtual void IfNeuron::proceedToNextState ( )

virtual

Proceed one time step.

This method can be overridden to implement the proceeding of one time step. This makes new information available at the current time. (See also proceedToNextState()). The default just writes stochNextValue into stochCurrentValue.

Reimplemented from StochasticProcess.

virtual void IfNeuron::removeStimulus ( int n )

virtual

Remove a stimulus.

This removes the nth stimulus from the differential equation

Implements Neuron.

virtual void IfNeuron::setCurrentValue ( double d )

inlinevirtual

Set the current value of the process.

This includes both the value of the neuron and the membrane, which is a separate object..

Reimplemented from StochasticProcess.

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virtual void IfNeuron::setNextValue ( double d )

inlinevirtual

Set the next value of the process.

This includes both the value of the neuron and the membrane, which is a separate object..

Reimplemented from StochasticProcess.

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virtual void IfNeuron::setParameter	(	const string &	name,
		const string &	value
	)

virtual

Set parameter.

Sets the value of a parameter using strings. If a parameter is described using multiple strings separated by space, this indicates a parameter of a parameter.

Parameters

name	name of parameter
value	value of parameter (used with operator<<)

Reimplemented from Parametric.

Public Member Functions

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation