def create_brain():
# Brain simulation set-up
sim.setup(timestep=0.1,
min_delay=0.1,
max_delay=20.0,
threads=1,
rng_seeds=[1234])
## NEURONS ##
# Neuronal parameters
NEURONPARAMS = {
'cm': 0.025,
'v_rest': -60.5,
'tau_m': 10.,
'e_rev_E': 0.0,
'e_rev_I': -75.0,
'v_reset': -60.5,
'v_thresh': -60.0,
'tau_refrac': 10.0,
'tau_syn_E': 2.5,
'tau_syn_I': 2.5
}
# Build the neuronal model
cell_class = sim.IF_cond_alpha(**NEURONPARAMS)
# Define the neuronal population
population = sim.Population(size=4, cellclass=cell_class)
## SYNAPSES ##
# Build the weights matrix
weights = np.zeros((2, 2))
weights[0, 1] = 1.
weights[1, 0] = 1.
weights *= 5e-5
# Synaptic parameters
SYNAPSE_PARAMS = {
"weight": weights,
"delay": 1.0,
'U': 1.0,
'tau_rec': 1.0,
'tau_facil': 1.0
}
# Build synaptic model
synapse_type = sim.TsodyksMarkramSynapse(**SYNAPSE_PARAMS)
## NETWORK ##
# Connect neurons
connector = sim.AllToAllConnector()
sim.Projection(presynaptic_population=population[0:2],
postsynaptic_population=population[2:4],
connector=connector,
synapse_type=synapse_type,
receptor_type='excitatory')
# Initialize the network
sim.initialize(population, v=population.get('v_rest'))
return population
def create_brain():
"""
Initializes PyNN with the minimal neuronal network
"""
sim.setup(timestep=0.1,
min_delay=0.1,
max_delay=20.0,
threads=1,
rng_seeds=[1234])
# Following parameters were taken from the husky braitenberg brain experiment (braitenberg.py)
SENSORPARAMS = {
'cm': 0.025,
'v_rest': -60.5,
'tau_m': 10.,
'e_rev_E': 0.0,
'e_rev_I': -75.0,
'v_reset': -60.5,
'v_thresh': -60.0,
'tau_refrac': 10.0,
'tau_syn_E': 2.5,
'tau_syn_I': 2.5
}
SYNAPSE_PARAMS = {
"weight": 0.5e-4,
"delay": 20.0,
'U': 1.0,
'tau_rec': 1.0,
'tau_facil': 1.0
}
cell_class = sim.IF_cond_alpha(**SENSORPARAMS)
# Define the network structure: 2 neurons (1 sensor and 1 actors)
population = sim.Population(size=2, cellclass=cell_class)
synapse_type = sim.TsodyksMarkramSynapse(**SYNAPSE_PARAMS)
connector = sim.AllToAllConnector()
# Connect neurons
sim.Projection(presynaptic_population=population[0:1],
postsynaptic_population=population[1:2],
connector=connector,
synapse_type=synapse_type,
receptor_type='excitatory')
sim.initialize(population, v=population.get('v_rest'))
return population
def create_brain():
"""
Initializes PyNN with the neuronal network that has to be simulated
"""
SENSORPARAMS = {'v_rest': -60.5,
'cm': 0.025,
'tau_m': 10.,
'tau_refrac': 10.0,
'tau_syn_E': 2.5,
'tau_syn_I': 2.5,
'e_rev_E': 0.0,
'e_rev_I': -75.0,
'v_thresh': -60.0,
'v_reset': -60.5}
GO_ON_PARAMS = {'v_rest': -60.5,
'cm': 0.025,
'tau_m': 10.0,
'e_rev_E': 0.0,
'e_rev_I': -75.0,
'v_reset': -61.6,
'v_thresh': -60.51,
'tau_refrac': 10.0,
'tau_syn_E': 2.5,
'tau_syn_I': 2.5}
# POPULATION_PARAMS = SENSORPARAMS * 5 + GO_ON_PARAMS + SENSORPARAMS * 2
population = sim.Population(8, sim.IF_cond_alpha())
population[0:5].set(**SENSORPARAMS)
population[5:6].set(**GO_ON_PARAMS)
population[6:8].set(**SENSORPARAMS)
# Shared Synapse Parameters
syn_params = {'U': 1.0, 'tau_rec': 1.0, 'tau_facil': 1.0}
# Synaptic weights
WEIGHT_RED_TO_ACTOR = 1.5e-4
WEIGHT_RED_TO_GO_ON = 1.2e-3 # or -1.2e-3?
WEIGHT_GREEN_BLUE_TO_ACTOR = 1.05e-4
WEIGHT_GO_ON_TO_RIGHT_ACTOR = 1.4e-4
DELAY = 0.1
# Connect neurons
CIRCUIT = population
SYN = sim.TsodyksMarkramSynapse(weight=abs(WEIGHT_RED_TO_ACTOR),
delay=DELAY, **syn_params)
sim.Projection(presynaptic_population=CIRCUIT[2:3],
postsynaptic_population=CIRCUIT[7:8],
connector=sim.AllToAllConnector(),
synapse_type=SYN,
receptor_type='excitatory')
sim.Projection(presynaptic_population=CIRCUIT[3:4],
postsynaptic_population=CIRCUIT[6:7],
connector=sim.AllToAllConnector(),
synapse_type=SYN,
receptor_type='excitatory')
SYN = sim.TsodyksMarkramSynapse(weight=abs(WEIGHT_RED_TO_GO_ON),
delay=DELAY, **syn_params)
sim.Projection(presynaptic_population=CIRCUIT[0:2],
postsynaptic_population=CIRCUIT[5:6],
connector=sim.AllToAllConnector(),
synapse_type=SYN,
receptor_type='inhibitory')
SYN = sim.TsodyksMarkramSynapse(weight=abs(WEIGHT_GREEN_BLUE_TO_ACTOR),
delay=DELAY, **syn_params)
sim.Projection(presynaptic_population=CIRCUIT[4:5],
postsynaptic_population=CIRCUIT[7:8],
connector=sim.AllToAllConnector(),
synapse_type=SYN,
receptor_type='excitatory')
SYN = sim.TsodyksMarkramSynapse(weight=abs(WEIGHT_GO_ON_TO_RIGHT_ACTOR),
delay=DELAY, **syn_params)
sim.Projection(presynaptic_population=CIRCUIT[5:6],
postsynaptic_population=CIRCUIT[7:8],
connector=sim.AllToAllConnector(),
synapse_type=SYN,
receptor_type='excitatory')
sim.initialize(population, v=population.get('v_rest'))
logger.info("Circuit description: " + str(population.describe()))
return population