Changes for page 03. Building and simulating a simple model
Last modified by adavison on 2022/10/04 13:55
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... ... @@ -44,7 +44,7 @@ 44 44 **Slide** listing prerequisites 45 45 ))) 46 46 47 -To follow this tutorial, you need a basic knowledge of neuroscience (high-school level or g reater), basic familiarity with the Python programming language, and you should have already followed our earlier tutorial video which guides you through the installation process.47 +To follow this tutorial, you need a basic knowledge of neuroscience (high-school level or higher), basic familiarity with the Python programming language, and you should have already followed our earlier tutorial video which guides you through the installation process. 48 48 49 49 This video covers PyNN 0.10. If you've installed a more recent version of PyNN, you might want to look for an updated version of this video. 50 50 ... ... @@ -84,7 +84,7 @@ 84 84 85 85 PyNN comes with a selection of integrate-and-fire models. We're going to use the IF_curr_exp model, where "IF" is for integrate-and-fire, "curr" means that synaptic responses are changes in current, and "exp" means that the shape of the current is a decaying exponential function. 86 86 87 -This is where we set the parameters of the model: the resting membrane potential is -65 millivolts, the spike threshold is -55 millivolts, the reset voltage after a spike is again -65 millivolts, the refractory period after a spike is one millisecond, the membrane time constant is 10 milliseconds, and the membrane capacitance is 1 nanofarad. We're also going to inject a constant bias current of 0.1 nanoamps into these neurons, so that we get some action potentials.87 +This is where we set the parameters of the model: the resting membrane potential is -65 millivolts, the spike threshold is -55 millivolts, the reset voltage after a spike is again -65 millivolts, the refractory period after a spike is one millisecond, the membrane time constant is 10 milliseconds, and the membrane capacitance is 1 nanofarad. We're also going to inject a constant bias current of 1.1 nanoamps into these neurons, so that we get some action potentials. 88 88 89 89 (% class="box infomessage" %) 90 90 ((( ... ... @@ -166,14 +166,14 @@ 166 166 \\(% style="color:#000000" %)"""Simple network model using PyNN""" 167 167 \\import pyNN.nest as sim(%%) 168 168 (% style="color:#000000" %)from pyNN.utility.plotting import Figure, Panel(%%) 169 -(% style="color:#e74c3c" %)from pyNN.random import RandomDistribution(%%) 169 +(% style="color:#e74c3c" %)from pyNN.random import RandomDistribution, NumpyRNG(%%) 170 170 (% style="color:#000000" %)sim.setup(timestep=0.1)(%%) 171 +(% style="color:#e74c3c" %)rng = NumpyRNG(seed=1)(%%) 171 171 (% style="color:#000000" %)cell_type = sim.IF_curr_exp( 172 - (% style="color:#e74c3c" %) v_rest=RandomDistribution('normal', mu=-65.0, sigma=1.0), 173 - v_thresh=RandomDistribution('normal', mu=-55.0, sigma=1.0), 174 - v_reset=RandomDistribution('normal', mu=-65.0, sigma=1.0), (%%) 175 -(% style="color:#000000" %) tau_refrac=1, tau_m=10, cm=1, i_offset=1.1)(%%) 176 - 173 + (% style="color:#e74c3c" %) v_rest=RandomDistribution('normal', mu=-65.0, sigma=1.0, rng=rng), 174 + v_thresh=RandomDistribution('normal', mu=-55.0, sigma=1.0, rng=rng), 175 + v_reset=RandomDistribution('normal', mu=-65.0, sigma=1.0, rng=rng), (%%) 176 +(% style="color:#000000" %) tau_refrac=1, tau_m=10, cm=1, i_offset=1.1) 177 177 178 178 **...** 179 179 ... ... @@ -263,7 +263,7 @@ 263 263 264 264 **...** 265 265 (% style="color:#000000" %)population2.record("v")(%%) 266 -(% style="color:#e74c3c" %)connection_algorithm = sim.FixedProbabilityConnector(p_connect=0.5) 266 +(% style="color:#e74c3c" %)connection_algorithm = sim.FixedProbabilityConnector(p_connect=0.5, rng=rng) 267 267 synapse_type = sim.StaticSynapse(weight=0.5, delay=0.5) 268 268 connections = sim.Projection(population1, population2, connection_algorithm, synapse_type)(%%) 269 269 (% style="color:#000000" %)sim.run(100.0)(%%) ... ... @@ -307,19 +307,20 @@ 307 307 \\(% style="color:#000000" %)"""Simple network model using PyNN""" 308 308 \\import pyNN.(% style="color:#e74c3c" %)neuron(% style="color:#000000" %) as sim(%%) 309 309 (% style="color:#000000" %)from pyNN.utility.plotting import Figure, Panel(%%) 310 -(% style="color:#000000" %)from pyNN.random import RandomDistribution(%%) 310 +(% style="color:#000000" %)from pyNN.random import RandomDistribution, NumpyRNG(%%) 311 311 (% style="color:#000000" %)sim.setup(timestep=0.1)(%%) 312 +(% style="color:#000000" %)rng = NumpyRNG(seed=1)(%%) 312 312 (% style="color:#000000" %)cell_type = sim.IF_curr_exp( 313 - (%style="color:#e74c3c" %) (% style="color:#000000" %)v_rest=RandomDistribution('normal', mu=-65.0, sigma=1.0),314 - v_thresh=RandomDistribution('normal', mu=-55.0, sigma=1.0), 315 - v_reset=RandomDistribution('normal', mu=-65.0, sigma=1.0 ),(%%)316 - (%style="color:#000000"%)(%%)317 - (% style="color:#000000" %)population1 = sim.Population(100, cell_type, label="Population 1")(%%)318 - (% style="color:#000000" %)population2 = sim.Population(100, cell_type, label="Population 2")314 + v_rest=RandomDistribution('normal', mu=-65.0, sigma=1.0, rng=rng), 315 + v_thresh=RandomDistribution('normal', mu=-55.0, sigma=1.0, rng=rng), 316 + v_reset=RandomDistribution('normal', mu=-65.0, sigma=1.0, rng=rng), 317 + tau_refrac=1, tau_m=10, cm=1, i_offset=1.1) 318 +population1 = sim.Population(100, cell_type, label="Population 1") 319 +population2 = sim.Population(100, cell_type, label="Population 2") 319 319 population2.set(i_offset=0) 320 320 population1.record("v") 321 -population2.record("v") (%%)322 - (% style="color:#000000" %)connection_algorithm = sim.FixedProbabilityConnector(p_connect=0.5)322 +population2.record("v") 323 +connection_algorithm = sim.FixedProbabilityConnector(p_connect=0.5, rng=rng) 323 323 synapse_type = sim.StaticSynapse(weight=0.5, delay=0.5) 324 324 connections = sim.Projection(population1, population2, connection_algorithm, synapse_type)(%%) 325 325 (% style="color:#000000" %)sim.run(100.0)(%%) ... ... @@ -355,7 +355,7 @@ 355 355 356 356 Of course, PyNN allows you to create much more complex networks than this, with more realistic neuron models, synaptic plasticity, spatial structure, and so on. You can also use other simulators, such as Brian or SpiNNaker, and you can run simulations in parallel on clusters or supercomputers. 357 357 358 -We will be releasing a series of tutorials, throughout th e restof 2021and 2022, to introduce these more advanced features of PyNN, so keep an eye on the EBRAINS website.359 +We will be releasing a series of tutorials, throughout this year, to introduce these more advanced features of PyNN, so keep an eye on the EBRAINS website. 359 359 360 360 (% class="box successmessage" %) 361 361 (((