neuron_model_lif_impl.h File Reference

Leaky Integrate and Fire neuron type. More...

#include "neuron_model.h"

Go to the source code of this file.

Data Structures
struct	neuron_params_t
	definition of neuron parameters More...
struct	neuron_t
	definition for LIF neuron state More...

Functions
static int32_t	lif_ceil_accum (REAL value)
	Performs a ceil operation on an accum.
static void	neuron_model_initialise (neuron_t *state, neuron_params_t *params, uint32_t n_steps_per_timestep)
static void	neuron_model_save_state (neuron_t *state, neuron_params_t *params)
static void	lif_neuron_closed_form (neuron_t *neuron, REAL V_prev, input_t input_this_timestep)
	simple Leaky I&F ODE
static state_t	neuron_model_state_update (uint16_t num_excitatory_inputs, const input_t *exc_input, uint16_t num_inhibitory_inputs, const input_t *inh_input, input_t external_bias, REAL current_offset, neuron_t *restrict neuron)
	primary function called in timer loop after synaptic updates
static void	neuron_model_has_spiked (neuron_t *restrict neuron)
	Indicates that the neuron has spiked.
static state_t	neuron_model_get_membrane_voltage (const neuron_t *neuron)
	get the neuron membrane voltage for a given neuron parameter set
static void	neuron_model_print_state_variables (const neuron_t *neuron)
static void	neuron_model_print_parameters (const neuron_t *neuron)

Detailed Description

Leaky Integrate and Fire neuron type.

Definition in file neuron_model_lif_impl.h.

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Data Structure Documentation

neuron_params_t

struct neuron_params_t

definition of neuron parameters

The state parameters of an Izhekevich model neuron.

definition for LIF neuron parameters

Definition at line 47 of file neuron_impl_stoc_exp.h.

Data Fields
UREAL	tau_ms	The tau value of the neuron.
UREAL	time_step	The timestep of the neuron being used. The time step in milliseconds. current timestep in ms
REAL	bias	The bias value.
uint32_t	refract_init	The initial refractory timer.
mars_kiss64_seed_t	random_seed	Random seed to use.
REAL	v_init	The initial membrane voltage.
REAL	v_reset	The reset membrane voltage after a spike.
UREAL	tau	The tau value of the neuron, multiplied by 2^v to get probability.
UREAL	tau_refract	The refractory period of the neuron in milliseconds. The refractory period of the neuron, in ms.
REAL	alpha	The alpha value of the neuron prob = (2^(-2^(alpha x voltage)))
REAL	V_init	membrane voltage [mV]
REAL	c_m	membrane capacitance [nF]
REAL	tau_m	membrane decay time constant
REAL	I_offset	offset current [nA]
REAL	V_reset	post-spike reset membrane voltage [mV]
REAL	T_refract_ms	refractory time of neuron [ms]
int32_t	refract_timer_init	initial refractory timer value (saved)
REAL	time_step	The time step in milliseconds. current timestep in ms
REAL	A
REAL	B
REAL	C
REAL	D
REAL	V
REAL	U
REAL	next_h	next value of this_h (saved)
REAL	V_rest	membrane resting voltage [mV]

neuron_t

struct neuron_t

definition for LIF neuron state

The state variables of an Izhekevich model neuron.

Definition at line 53 of file neuron_model_if_trunc.h.

Data Fields
REAL	V_membrane	membrane voltage [mV]
REAL	R_membrane	membrane resistance [MOhm]
REAL	I_offset	offset current [nA]
int32_t	refract_timer	countdown to end of next refractory period [timesteps]
REAL	V_reset	post-spike reset membrane voltage [mV]
int32_t	T_refract	refractory time of neuron [timesteps]
REAL	A
REAL	B
REAL	C
REAL	D
REAL	V
REAL	U
REAL	this_h	current timestep
REAL	reset_h	timestep to reset to when not just spiked
REAL	V_rest	membrane resting voltage [mV]
REAL	exp_TC	'fixed' computation parameter - time constant multiplier for closed-form solution exp(-(machine time step in ms)/(R * C)) [.]

Function Documentation

lif_ceil_accum()

static int32_t lif_ceil_accum ( REAL  value )

inlinestatic

Performs a ceil operation on an accum.

Parameters

[in]

value

The value to ceil

Returns

The ceil of the value

Definition at line 87 of file neuron_model_lif_impl.h.

neuron_model_initialise()

static void neuron_model_initialise ( neuron_t *  state, neuron_params_t *  params, uint32_t  n_steps_per_timestep  )

inlinestatic

Definition at line 97 of file neuron_model_lif_impl.h.

neuron_model_save_state()

static void neuron_model_save_state ( neuron_t *  state, neuron_params_t *  params  )

inlinestatic

Definition at line 110 of file neuron_model_lif_impl.h.

lif_neuron_closed_form()

static void lif_neuron_closed_form ( neuron_t *  neuron, REAL  V_prev, input_t  input_this_timestep  )

inlinestatic

simple Leaky I&F ODE

Parameters

[in,out]	neuron	The neuron to update
[in]	V_prev	previous voltage
[in]	input_this_timestep	The input to apply

Definition at line 119 of file neuron_model_lif_impl.h.

neuron_model_state_update()

static state_t neuron_model_state_update ( uint16_t  num_excitatory_inputs, const input_t *  exc_input, uint16_t  num_inhibitory_inputs, const input_t *  inh_input, input_t  external_bias, REAL  current_offset, neuron_t *restrict  neuron  )

inlinestatic

primary function called in timer loop after synaptic updates

Parameters

[in]	num_excitatory_inputs	Number of excitatory receptor types.
[in]	exc_input	Pointer to array of inputs per receptor type received this timer tick that produce a positive reaction within the neuron in terms of stimulation.
[in]	num_inhibitory_inputs	Number of inhibitory receptor types.
[in]	inh_input	Pointer to array of inputs per receptor type received this timer tick that produce a negative reaction within the neuron in terms of stimulation.
[in]	external_bias	This is the intrinsic plasticity which could be used for ac, noisy input etc etc. (general purpose input)
[in,out]	neuron	the pointer to a neuron parameter struct which contains all the parameters for a specific neuron

Returns

the value to be compared with a threshold value to determine if the neuron has spiked

Definition at line 142 of file neuron_model_lif_impl.h.

neuron_model_has_spiked()

static void neuron_model_has_spiked ( neuron_t *restrict  neuron )

inlinestatic

Indicates that the neuron has spiked.

Parameters

[in,out]

neuron

pointer to a neuron parameter struct which contains all the parameters for a specific neuron

Definition at line 174 of file neuron_model_lif_impl.h.

neuron_model_get_membrane_voltage()

static state_t neuron_model_get_membrane_voltage ( const neuron_t *  neuron )

inlinestatic

get the neuron membrane voltage for a given neuron parameter set

Parameters

[in]

neuron

a pointer to a neuron parameter struct which contains all the parameters for a specific neuron

Returns

the membrane voltage for a given neuron with the neuron parameters specified in neuron

Definition at line 187 of file neuron_model_lif_impl.h.

neuron_model_print_state_variables()

static void neuron_model_print_state_variables ( const neuron_t *  neuron )

inlinestatic

Definition at line 191 of file neuron_model_lif_impl.h.

neuron_model_print_parameters()

static void neuron_model_print_parameters ( const neuron_t *  neuron )

inlinestatic

Definition at line 196 of file neuron_model_lif_impl.h.