iaf_chxk_2008 – Conductance-based leaky integrate-and-fire neuron model supporting precise spike times used in Casti et al. 2008 ================================================================================================================================ Description +++++++++++ ``iaf_chxk_2008`` is an implementation of a spiking neuron using IAF dynamics with conductance-based synapses [1]_. A spike is emitted when the membrane potential is crossed from below. After a spike, an afterhyperpolarizing (AHP) conductance is activated which repolarizes the neuron over time. Membrane potential is not reset explicitly and the model also has no explicit refractory time. The AHP conductance and excitatory and inhibitory synaptic input conductances follow alpha-function time courses as in the ``iaf_cond_alpha`` model. .. note:: In accordance with the original Fortran implementation of the model used in [1]_, the activation time point for the AHP following a spike is determined by linear interpolation within the time step during which the threshold was crossed. ``iaf_chxk_2008`` neurons therefore emit spikes with precise spike time information, but they ignore precise spike times when handling synaptic input. .. note:: In the original Fortran implementation underlying [1]_, all previous AHP activation was discarded when a new spike occurred, leading to reduced AHP currents in particular during periods of high spiking activity. Set ``ahp_bug`` to ``true`` to obtain this behavior in the model. Parameters ++++++++++ The following parameters can be set in the status dictionary. ======== ======= =========================================================== V_m mV Membrane potential E_L mV Leak reversal potential C_m pF Capacity of the membrane V_th mV Spike threshold E_ex mV Excitatory reversal potential E_in mV Inhibitory reversal potential g_L nS Leak conductance tau_ex ms Rise time of the excitatory synaptic alpha function tau_in ms Rise time of the inhibitory synaptic alpha function I_e pA Constant input current tau_ahp ms Afterhyperpolarization (AHP) time constant E_ahp mV AHP potential g_ahp nS AHP conductance ahp_bug boolean Defaults to false. If true, behaves like original model implementation ======== ======= =========================================================== References ++++++++++ .. [1] Casti A, Hayot F, Xiao Y, Kaplan E (2008) A simple model of retina-LGN transmission. Journal of Computational Neuroscience 24:235-252. DOI: https://doi.org/10.1007/s10827-007-0053-7 Sends +++++ SpikeEvent Receives ++++++++ SpikeEvent, CurrentEvent See also ++++++++ :doc:`Neuron `, :doc:`Integrate-And-Fire `, :doc:`Conductance-Based `, :doc:`Precise `