iaf_psc_exp_dend_neuron ####################### iaf_psc_exp_dend - Leaky integrate-and-fire neuron model with exponential PSCs Description +++++++++++ iaf_psc_exp is an implementation of a leaky integrate-and-fire model with exponential-kernel postsynaptic currents (PSCs) according to [1]_. Thus, postsynaptic currents have an infinitely short rise time. The threshold crossing is followed by an absolute refractory period (t_ref) during which the membrane potential is clamped to the resting potential and spiking is prohibited. .. note:: If tau_m is very close to tau_syn_ex or tau_syn_in, numerical problems may arise due to singularities in the propagator matrics. If this is the case, replace equal-valued parameters by a single parameter. For details, please see ``IAF_neurons_singularity.ipynb`` in the NEST source code (``docs/model_details``). References ++++++++++ .. [1] Tsodyks M, Uziel A, Markram H (2000). Synchrony generation in recurrent networks with frequency-dependent synapses. The Journal of Neuroscience, 20,RC50:1-5. URL: https://infoscience.epfl.ch/record/183402 See also ++++++++ iaf_cond_exp Parameters ++++++++++ .. csv-table:: :header: "Name", "Physical unit", "Default value", "Description" :widths: auto "C_m", "pF", "250pF", "Capacity of the membrane" "tau_m", "ms", "10ms", "Membrane time constant" "tau_syn_inh", "ms", "2ms", "Time constant of inhibitory synaptic current" "tau_syn_exc", "ms", "2ms", "Time constant of excitatory synaptic current" "refr_T", "ms", "2ms", "Duration of refractory period" "E_L", "mV", "-70mV", "Resting potential" "V_reset", "mV", "-70mV", "Reset potential of the membrane" "V_th", "mV", "-55mV", "Spike threshold potential" "I_e", "pA", "0pA", "constant external input current" State variables +++++++++++++++ .. csv-table:: :header: "Name", "Physical unit", "Default value", "Description" :widths: auto "V_m", "mV", "E_L", "Membrane potential" "I_dend", "pA", "0pA", "Third factor, to be read out by synapse during weight update" "refr_t", "ms", "0ms", "Refractory period timer" "is_refractory", "boolean", "false", "" Equations +++++++++ .. math:: \frac{ dV_{m} } { dt }= \frac{ -(V_{m} - E_{L}) } { \tau_{m} } + \frac 1 { C_{m} } \left( { (I_{syn} + I_{e} + I_{stim}) } \right) Source code +++++++++++ The model source code can be found in the NESTML models repository here: `iaf_psc_exp_dend_neuron `_. .. include:: iaf_psc_exp_dend_neuron_characterisation.rst .. footer:: Generated at 2024-05-22 14:51:14.593810