Пример #1
0
def CUBA(geometry, ref=5.0, name='CUBA'):
    var2index = dict(V=0, ge=1, gi=2)
    num, geometry = nn.format_geometry(geometry)

    state = nn.initial_neu_state(3, num)
    state[0] = Vr + np.random.rand(num) * (Vt - Vr)

    def update_state(neu_state, t):
        # get neuron state
        not_ref = (t - neu_state[-2]) > ref
        not_ref_idx = np.where(not_ref)[0]
        # neu_state[-5] = not_ref
        V = neu_state[0][not_ref_idx]
        ge = neu_state[1][not_ref_idx]
        gi = neu_state[2][not_ref_idx]
        # calculate neuron state
        ge -= ge / taue * dt
        gi -= gi / taui * dt
        V += (ge + gi - (V - El)) / taum * dt
        neu_state[0][not_ref_idx] = V
        neu_state[1][not_ref_idx] = ge
        neu_state[2][not_ref_idx] = gi
        spike_idx = nn.judge_spike(neu_state, Vt, t)
        neu_state[0][spike_idx] = Vr

    return nn.Neurons(**locals())
Пример #2
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def COBA(geometry, ref=5.0, name='COBA'):
    var2index = dict(V=0, ge=1, gi=2)
    num, geometry = nn.format_geometry(geometry)

    state = nn.initial_neu_state(3, num)
    state[0] = np.random.randn(num) * 5. - 55.

    def update_state(neu_state, t):
        # get neuron index not in refractory
        not_ref = (t - neu_state[-2]) > ref
        not_ref_idx = np.where(not_ref)[0]
        neu_state[-5] = not_ref
        # get neuron state
        V = neu_state[0][not_ref_idx]
        ge = neu_state[1][not_ref_idx]
        gi = neu_state[2][not_ref_idx]
        # calculate neuron state
        ge -= ge / taue * dt
        gi -= gi / taui * dt
        V += (ge * (Erev_exc - V) + gi * (Erev_inh - V) -
              (V - El) + I) / taum * dt
        neu_state[0][not_ref_idx] = V
        neu_state[1][not_ref_idx] = ge
        neu_state[2][not_ref_idx] = gi
        spike_idx = nn.judge_spike(neu_state, Vt, t)
        neu_state[0][spike_idx] = Vr

    return nn.Neurons(**locals())
Пример #3
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def LIF(geometry, tau=100, V_reset=0., Vth=1.):
    var2index = dict(V=0)
    num, geometry = nn.format_geometry(geometry)

    state = nn.initial_neu_state(1, num)
    state[0] = V_reset

    @nn.integrate
    def int_f(V, t, Isyn):
        return (-V + Isyn) / tau

    def update_state(neu_state, t):
        V_new = int_f(neu_state[0], t, neu_state[-1])
        neu_state[0] = V_new
        spike_idx = nn.judge_spike(neu_state, Vth, t)
        neu_state[0][spike_idx] = V_reset

    return nn.Neurons(**locals())
Пример #4
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def COBA_HH(geometry, name='COBA_HH'):
    var2index = dict(V=0, m=1, h=2, n=3, ge=4, gi=5)
    num, geometry = nn.format_geometry(geometry)

    # V, m, h, n, ge, gi
    state = nn.initial_neu_state(6, num)
    state[0] = El + (np.random.randn(num_exc + num_inh) * 5 - 5)
    state[4] = (np.random.randn(num_exc + num_inh) * 1.5 + 4) * 10. / unit
    state[5] = (np.random.randn(num_exc + num_inh) * 12 + 20) * 10. / unit

    def update_state(neu_state, t):
        # get neuron state
        V = neu_state[0]
        m = neu_state[1]
        h = neu_state[2]
        n = neu_state[3]
        ge = neu_state[4]
        gi = neu_state[5]

        # calculate neuron state
        m_alpha = 0.32 * (13 - V + VT) / (np.exp((13 - V + VT) / 4) - 1.)
        m_beta = 0.28 * (V - VT - 40) / (np.exp((V - VT - 40) / 5) - 1)
        h_alpha = 0.128 * np.exp((17 - V + VT) / 18)
        h_beta = 4. / (1 + np.exp((40 - V + VT) / 5))
        n_alpha = 0.032 * (15 - V + VT) / (np.exp((15 - V + VT) / 5) - 1.)
        n_beta = .5 * np.exp((10 - V + VT) / 40)

        # m channel
        fm = (m_alpha * (1 - m) - m_beta * m)
        dfm_dm = - m_alpha - m_beta
        m = m + (np.exp(dfm_dm * dt) - 1) / dfm_dm * fm
        neu_state[1] = m

        # h channel
        fh = (h_alpha * (1 - h) - h_beta * h)
        dfh_dh = - h_alpha - h_beta
        h = h + (np.exp(dfh_dh * dt) - 1) / dfh_dh * fh
        neu_state[2] = h

        # n channel
        fn = (n_alpha * (1 - n) - n_beta * n)
        dfn_dn = - n_alpha - h_beta
        n = n + (np.exp(dfn_dn * dt) - 1) / dfn_dn * fn
        neu_state[3] = n

        # ge
        fge = - ge / taue
        dfge_dge = - 1 / taue
        ge = ge + (np.exp(dfge_dge * dt) - 1) / dfge_dge * fge
        neu_state[4] = ge

        # gi
        fgi = - gi / taui
        dfgi_dgi = - 1 / taui
        gi = gi + (np.exp(dfgi_dgi * dt) - 1) / dfgi_dgi * fgi
        neu_state[5] = gi

        # V
        g_na_ = g_na * (m * m * m) * h
        g_kd_ = g_kd * (n * n * n * n)
        fv = (gl * (El - V) + ge * (Ee - V) + gi * (Ei - V) -
              g_na_ * (V - ENa) - g_kd_ * (V - EK)) / Cm
        dfv_dv = (-gl - ge - gi - g_na_ - g_kd_) / Cm
        V = V + (np.exp(dfv_dv * dt) - 1) / dfv_dv * fv
        neu_state[0] = V

        # spike
        nn.judge_spike(neu_state, Vt, t)

    return nn.Neurons(**locals())