iaf_cond_alpha_mc – Multi-compartment conductance-based leaky integrate-and-fire neuron model
=============================================================================================
Description
+++++++++++
THIS MODEL IS A PROTOTYPE FOR ILLUSTRATION PURPOSES. IT IS NOT YET
FULLY TESTED. USE AT YOUR OWN PERIL!
``iaf_cond_alpha_mc`` is an implementation of a multi-compartment spiking
neuron using IAF dynamics with conductance-based synapses. It serves
mainly to illustrate the implementation of :ref:`multicompartment models
` in NEST.
The model has three compartments: soma, proximal and distal dendrite,
labeled as s, p, and d, respectively. Compartments are connected through
passive conductances as follows
.. math::
C_{m.s} d/dt V_{m.s} = \ldots - g_{sp} ( V_{m.s} - V_{m.p} ) \\
C_{m.p} d/dt V_{m.p} = \ldots - g_{sp} ( V_{m.p} - V_{m.s} )
- g_{pd} ( V_{m.p} - V_{m.d} ) \\
C_{m.d} d/dt V_{m.d} = \ldots \qquad - g_{pd} ( V_{m.d} - V_{m.p} )
A spike is fired when the somatic membrane potential exceeds threshold,
:math:`V_{m.s} >= V_{th}`. After a spike, somatic membrane potential is
clamped to a reset potential, :math:` V_{m.s} == V_{reset}`, for the refractory
period. Dendritic membrane potentials are not manipulated after a spike.
There is one excitatory and one inhibitory conductance-based synapse
onto each compartment, with alpha-function time course. The alpha
function is normalized such that an event of weight 1.0 results in a
peak current of 1 nS at :math:`t = \tau_{syn}`. Each compartment can also
receive current input from a current generator, and an external (rheobase)
current can be set for each compartment.
Synapses, including those for injection external currents, are addressed through
the receptor types given in the ``receptor_types`` entry of the state dictionary.
Note that in contrast to the single-compartment ``iaf_cond_alpha`` model, all
synaptic weights must be positive numbers!
See also [1]_, [2]_.
Parameters
++++++++++
The following parameters can be set in the status dictionary. Parameters
for each compartment are collected in a sub-dictionary; these sub-dictionaries
are called "soma", "proximal", and "distal", respectively. In the list below,
these parameters are marked with an asterisk.
============ ======= ==========================================================
V_m* mV Membrane potential
E_L* mV Leak reversal potential
C_m* pF Capacity of the membrane
E_ex* mV Excitatory reversal potential
E_in* mV Inhibitory reversal potential
g_L* nS Leak conductance
tau_syn_ex* ms Rise time of the excitatory synaptic alpha function
tau_syn_in* ms Rise time of the inhibitory synaptic alpha function
I_e* pA Constant input current
g_sp nS Conductance connecting soma and proximal dendrite
g_pd nS Conductance connecting proximal and distal dendrite
t_ref ms Duration of refractory period
V_th mV Spike threshold in mV
V_reset mV Reset potential of the membrane
============ ======= ==========================================================
Sends
+++++
SpikeEvent
Receives
++++++++
SpikeEvent, CurrentEvent, DataLoggingRequest
References
++++++++++
.. [1] Meffin H, Burkitt AN, Grayden DB (2004). An analytical
model for the large, fluctuating synaptic conductance state typical of
neocortical neurons in vivo. Journal of Computational Neuroscience,
16:159-175.
DOI: https://doi.org/10.1023/B:JCNS.0000014108.03012.81
.. [2] Bernander O, Douglas RJ, Martin KAC, Koch C (1991). Synaptic background
activity influences spatiotemporal integration in single pyramidal
cells. Proceedings of the National Academy of Science USA,
88(24):11569-11573.
DOI: https://doi.org/10.1073/pnas.88.24.11569
See also
++++++++
:doc:`Neuron `, :doc:`Integrate-And-Fire `, :doc:`Conductance-Based `
Examples using this model
+++++++++++++++++++++++++
.. listexamples:: iaf_cond_alpha_mc