# izhikevich_tutorial_neuron
# ##########################
#
#
# Copyright statement
# +++++++++++++++++++
#
# This file is part of NEST.
#
# Copyright (C) 2004 The NEST Initiative
#
# NEST is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 2 of the License, or
# (at your option) any later version.
#
# NEST is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with NEST.  If not, see <http://www.gnu.org/licenses/>.
#
model izhikevich_tutorial_neuron:

    state:
        v mV = -65 mV    # Membrane potential in mV
        u real = 0    # Membrane potential recovery variable

    equations:
        v' = (.04 * v * v / 1 mV + 5 * v + (140 - u) * 1 mV + (I_e * 1 GOhm)) / 1 ms
        u' = a * (b * v - u * 1 mV) / (1 mV*ms)

    parameters:
        a real = .02    # describes time scale of recovery variable
        b real = .2     # sensitivity of recovery variable
        c mV = -65 mV   # after-spike reset value of v
        d real = 8      # after-spike reset value of u

    internals:
        unit_psp mV = 1 mV        # Unitary postsynaptic potential amplitude

    input:
        spikes <- spike
        I_e pA <- continuous

    output:
        spike

    update:
        integrate_odes()

    onReceive(spikes):
        # add synaptic current
        v += unit_psp * spikes * 1 s

    onCondition(v >= 30 mV):
        # threshold crossing
        v = c
        u += d
        emit_spike()