synapse_types_alpha_impl.h File Reference

implementation of synapse_types.h for an alpha synapse behaviour More...

#include <neuron/decay.h>
#include <debug.h>
#include "synapse_types.h"

Go to the source code of this file.

Data Structures
struct	alpha_params_t
	Parameters of an alpha synaptic input. More...
struct	synapse_types_params_t
struct	alpha_state_t
	Internal structure of an alpha-shaped synaptic input. More...
struct	synapse_types_t
	Delta synapses support just a single excitatory and inhibitory input each. More...

Macros
#define	SYNAPSE_TYPE_BITS   1
	Number of bits to encode the synapse type.
#define	SYNAPSE_TYPE_COUNT   2
	Number of synapse types.
#define	NUM_EXCITATORY_RECEPTORS   1
	Number of excitatory receptors.
#define	NUM_INHIBITORY_RECEPTORS   1
	Number of inhibitory receptors.

Enumerations
enum	synapse_alpha_input_buffer_regions { EXCITATORY , INHIBITORY }
	The supported synapse type indices. More...

Functions
static void	get_alpha_state (alpha_state_t *state, alpha_params_t *params, REAL time_step_ms, uint32_t n_steps_per_timestep)
static void	synapse_types_initialise (synapse_types_t *state, synapse_types_params_t *params, uint32_t n_steps_per_timestep)
static void	synapse_types_save_state (synapse_types_t *state, synapse_types_params_t *params)
static void	alpha_shaping (alpha_state_t *a_params)
	Applies alpha shaping to a parameter.
static void	synapse_types_shape_input (synapse_types_t *parameters)
	decays the stuff thats sitting in the input buffers as these have not yet been processed and applied to the neuron.
static void	add_input_alpha (alpha_state_t *a_params, input_t input)
	helper function to add input for a given timer period to a given neuron
static void	synapse_types_add_neuron_input (index_t synapse_type_index, synapse_types_t *parameters, input_t input)
	adds the inputs for a give timer period to a given neuron that is being simulated by this model
static input_t *	synapse_types_get_excitatory_input (input_t *excitatory_response, synapse_types_t *parameters)
	extracts the excitatory input buffers from the buffers available for a given neuron ID
static input_t *	synapse_types_get_inhibitory_input (input_t *inhibitory_response, synapse_types_t *parameters)
	extracts the inhibitory input buffers from the buffers available for a given neuron ID
static const char *	synapse_types_get_type_char (index_t synapse_type_index)
	returns a human readable character for the type of synapse.
static void	synapse_types_print_input (synapse_types_t *parameters)
	prints the input for a neuron ID given the available inputs currently only executed when the models are in debug mode, as the prints are controlled from the synapses.c print_inputs() method.
static void	synapse_types_print_parameters (synapse_types_t *parameters)
	prints the parameters of the synapse type

Detailed Description

implementation of synapse_types.h for an alpha synapse behaviour

Definition in file synapse_types_alpha_impl.h.

---

Data Structure Documentation

alpha_params_t

struct alpha_params_t

Parameters of an alpha synaptic input.

Definition at line 48 of file synapse_types_alpha_impl.h.

Data Fields
input_t	lin_init
input_t	exp_init
input_t	q_init
REAL	tau

synapse_types_params_t

struct synapse_types_params_t

Definition at line 55 of file synapse_types_alpha_impl.h.

Data Fields
alpha_params_t	exc	First excitatory synaptic input.
alpha_params_t	inh	Inhibitory synaptic input
REAL	time_step_ms
input_t	exc
input_t	inh
exp_params_t	exc	First excitatory synaptic input.
exp_params_t	exc2	Second excitatory synaptic input.
exp_params_t	inh	Inhibitory synaptic input
input_t	multiplicator_init	Output scaling factor derived from first excitatory input.
input_t	exc2_old_init	History storage used to reset synaptic state.
input_t	scaling_factor	Scaling factor for the secondary response.
REAL	timestep_ms	The time step in milliseconds.

alpha_state_t

struct alpha_state_t

Internal structure of an alpha-shaped synaptic input.

Definition at line 62 of file synapse_types_alpha_impl.h.

Data Fields
input_t	lin_buff	buffer for linear term
input_t	exp_buff	buffer for exponential term
input_t	dt_divided_by_tau_sqr	τ-1 pre-multiplied by dt
decay_t	decay	Exponential decay multiplier.
input_t	q_buff	Temporary value of input.

synapse_types_t

struct synapse_types_t

Delta synapses support just a single excitatory and inhibitory input each.

Definition at line 71 of file synapse_types_alpha_impl.h.

Data Fields
alpha_state_t	exc	Excitatory synaptic input. First excitatory synaptic input.
alpha_state_t	inh	Inhibitory synaptic input. Inhibitory synaptic input
input_t	exc	Excitatory synaptic input.
input_t	inh	Inhibitory synaptic input.
exp_state_t	exc	First excitatory synaptic input. Excitatory synaptic input.
exp_state_t	exc2	Second excitatory synaptic input.
exp_state_t	inh	Inhibitory synaptic input. Inhibitory synaptic input
input_t	multiplicator	Output scaling factor derived from first excitatory input.
input_t	exc2_old	History storage used to reset synaptic state.
input_t	scaling_factor	Scaling factor for the secondary response.

Macro Definition Documentation

SYNAPSE_TYPE_BITS

#define SYNAPSE_TYPE_BITS   1

Number of bits to encode the synapse type.

ceil(log2(SYNAPSE_TYPE_COUNT))

Definition at line 30 of file synapse_types_alpha_impl.h.

SYNAPSE_TYPE_COUNT

#define SYNAPSE_TYPE_COUNT   2

Number of synapse types.

NUM_EXCITATORY_RECEPTORS + NUM_INHIBITORY_RECEPTORS

Definition at line 33 of file synapse_types_alpha_impl.h.

NUM_EXCITATORY_RECEPTORS

#define NUM_EXCITATORY_RECEPTORS   1

Number of excitatory receptors.

Definition at line 36 of file synapse_types_alpha_impl.h.

NUM_INHIBITORY_RECEPTORS

#define NUM_INHIBITORY_RECEPTORS   1

Number of inhibitory receptors.

Definition at line 38 of file synapse_types_alpha_impl.h.

Enumeration Type Documentation

synapse_alpha_input_buffer_regions

enum synapse_alpha_input_buffer_regions

The supported synapse type indices.

Enumerator
EXCITATORY	Excitatory synaptic input.
INHIBITORY	Inhibitory synaptic input.

Definition at line 77 of file synapse_types_alpha_impl.h.

Function Documentation

get_alpha_state()

static void get_alpha_state ( alpha_state_t *  state, alpha_params_t *  params, REAL  time_step_ms, uint32_t  n_steps_per_timestep  )

inlinestatic

Definition at line 86 of file synapse_types_alpha_impl.h.

synapse_types_initialise()

static void synapse_types_initialise ( synapse_types_t *  state, synapse_types_params_t *  params, uint32_t  n_steps_per_timestep  )

inlinestatic

Definition at line 98 of file synapse_types_alpha_impl.h.

synapse_types_save_state()

static void synapse_types_save_state ( synapse_types_t *  state, synapse_types_params_t *  params  )

static

Definition at line 104 of file synapse_types_alpha_impl.h.

alpha_shaping()

static void alpha_shaping ( alpha_state_t *  a_params )

inlinestatic

Applies alpha shaping to a parameter.

Parameters

[in,out]

a_params

The parameter to shape

Definition at line 115 of file synapse_types_alpha_impl.h.

synapse_types_shape_input()

static void synapse_types_shape_input ( synapse_types_t *  parameters )

inlinestatic

decays the stuff thats sitting in the input buffers as these have not yet been processed and applied to the neuron.

This is to compensate for the valve behaviour of a synapse in biology (spike goes in, synapse opens, then closes slowly) plus the leaky aspect of a neuron.

Parameters

[in,out]

parameters

the parameters to update

Definition at line 131 of file synapse_types_alpha_impl.h.

add_input_alpha()

static void add_input_alpha ( alpha_state_t *  a_params, input_t  input  )

inlinestatic

helper function to add input for a given timer period to a given neuron

Parameters

[in]	a_params	the parameter to update
[in]	input	the input to add.

Definition at line 141 of file synapse_types_alpha_impl.h.

synapse_types_add_neuron_input()

static void synapse_types_add_neuron_input ( index_t  synapse_type_index, synapse_types_t *  parameters, input_t  input  )

inlinestatic

adds the inputs for a give timer period to a given neuron that is being simulated by this model

Add input from ring buffer. Zero if no spikes, otherwise one or more weights

Parameters

[in]	synapse_type_index	the type of input that this input is to be considered (aka excitatory or inhibitory etc)
[in,out]	parameters	the parameters to update
[in]	input	the inputs for that given synapse_type.

Definition at line 160 of file synapse_types_alpha_impl.h.

synapse_types_get_excitatory_input()

static input_t * synapse_types_get_excitatory_input ( input_t *  excitatory_response, synapse_types_t *  parameters  )

inlinestatic

extracts the excitatory input buffers from the buffers available for a given neuron ID

Parameters

[in,out]	excitatory_response	Buffer to put response in
[in]	parameters	the pointer to the parameters to use

Returns

Pointer to array of excitatory input buffers for a given neuron ID.

Definition at line 180 of file synapse_types_alpha_impl.h.

synapse_types_get_inhibitory_input()

static input_t * synapse_types_get_inhibitory_input ( input_t *  inhibitory_response, synapse_types_t *  parameters  )

inlinestatic

extracts the inhibitory input buffers from the buffers available for a given neuron ID

Parameters

[in,out]	inhibitory_response	Buffer to put response in
[in]	parameters	the pointer to the parameters to use

Returns

Pointer to array of inhibitory input buffers for a given neuron ID.

Definition at line 192 of file synapse_types_alpha_impl.h.

synapse_types_get_type_char()

static const char * synapse_types_get_type_char ( index_t  synapse_type_index )

inlinestatic

returns a human readable character for the type of synapse.

Examples would be X = excitatory types, I = inhibitory types, etc.

Parameters

[in]

synapse_type_index

the synapse type index (there is a specific index interpretation in each synapse type)

Returns

a human readable character representing the synapse type.

Definition at line 205 of file synapse_types_alpha_impl.h.

synapse_types_print_input()

static void synapse_types_print_input ( synapse_types_t *  parameters )

inlinestatic

prints the input for a neuron ID given the available inputs currently only executed when the models are in debug mode, as the prints are controlled from the synapses.c print_inputs() method.

Parameters

[in]

parameters

the pointer to the parameters to print

Definition at line 222 of file synapse_types_alpha_impl.h.

synapse_types_print_parameters()

static void synapse_types_print_parameters ( synapse_types_t *  parameters )

inlinestatic

prints the parameters of the synapse type

Parameters

[in]

parameters

the pointer to the parameters to print

Definition at line 231 of file synapse_types_alpha_impl.h.