DC Propagation block

This example provides an example of action potential propagation block using a DC stimulation. This is perfectly working in silico, but can be unsafe in vivo as long DC values are unbalanced and can damage tissues surrounding the electrode

import nrv
import numpy as np
import matplotlib.pyplot as plt

if __name__ == '__main__':
    model = 'MRG'
    diam = 10
    y = 0
    z = 0
    n_node = 50


    t_sim = 50
    t_position=0.05
    t_start=20
    t_duration=1
    t_amplitude=1

    b_start = 3
    b_duration = t_sim
    block_amp = 100
    nseg = 3
    material = nrv.load_material('endoneurium_bhadra')


    L=nrv.get_length_from_nodes(diam,n_node)

    axon = nrv.myelinated(y,z,diam,L,rec='nodes',dt=0.005,Nseg_per_sec=nseg,model=model)

    y_elec = 100
    z_elec = 0
    x_elec = axon.x_nodes[np.int32(n_node/2)]       # electrode y position, in [um]
    E1 = nrv.point_source_electrode(x_elec,y_elec,z_elec)

    # insert test spike
    axon.insert_I_Clamp(t_position, t_start, t_duration, t_amplitude)
    # extra-cellular stimulation
    stim_1 = nrv.stimulus()
    stim_1.biphasic_pulse(b_start, block_amp, b_duration, 0, 0,anod_first=False)

    stim_extra = nrv.stimulation(material)
    stim_extra.add_electrode(E1,stim_1)
    axon.attach_extracellular_stimulation(stim_extra)

    # simulate axon activity
    results = axon.simulate(t_sim=t_sim)#,footprints = footprints)
    results.rasterize()

    fig, axs = plt.subplots(2)
    results.plot_x_t(axs[0],'V_mem')
    axs[0].set_ylabel("Axon x-axis (µm)")
    axs[0].set_xlabel("Time (ms)")
    axs[0].set_xlim(0,30)
    axs[0].set_ylim(0,np.max(results.x_rec))

    results.raster_plot(axs[1],'V_mem')
    axs[1].set_ylabel("Axon x-axis (µm)")
    axs[1].set_xlabel("Time (ms)")
    axs[1].set_xlim(0,30)
    axs[1].set_ylim(0,np.max(results.x_rec))

    fig.tight_layout()
    plt.show()