hh_cond_exp_traub – Hodgkin-Huxley model for Brette et al (2007) review
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Description
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``hh_cond_exp_traub`` is an implementation of a modified Hodgkin-Huxley model.

This model was specifically developed for a major review of simulators [1]_,
based on a model of hippocampal pyramidal cells by Traub and Miles [2]_.
The key differences between the current model and the model in [2]_ are:

- This model is a point neuron, not a compartmental model.
- This model includes only ``I_Na`` and ``I_K``, with simpler ``I_K`` dynamics than
  in [2]_, so it has only three instead of eight gating variables;
  in particular, all Ca dynamics have been removed.
- Incoming spikes induce an instantaneous conductance change followed by
  exponential decay instead of activation over time.

This model is primarily provided as reference implementation for hh_coba
example of the Brette et al (2007) review. Default parameter values are chosen
to match those used with NEST 1.9.10 when preparing data for [1]_. Code for all
simulators covered is available from ModelDB [3]_.

.. note::
   In this model, a spike is emitted if :math:`V_m \geq V_T + 30` mV and :math:`V_m`
   has fallen during the current time step.

   To avoid multiple spikes from occurring during the falling flank of a
   spike, it is essential to choose a sufficiently long refractory period.
   Traub and Miles used  :math:`t_{ref} = 3` ms ([2]_, p 118), while we used
   :math:`t_{ref} = 2` ms in [2]_.

Parameters
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The following parameters can be set in the status dictionary.

=========== ======  =========================================================
V_m          mV     Membrane potential
V_T          mV     Voltage offset that controls dynamics. For default
                    parameters, V_T = -63mV results in a threshold around
                    -50mV.
E_L          mV     Leak reversal potential
C_m          pF     Capacity of the membrane
g_L          nS     Leak conductance
tau_syn_ex   ms     Time constant of the excitatory synaptic exponential
                    function
tau_syn_in   ms     Time constant of the inhibitory synaptic exponential
                    function
t_ref        ms     Duration of refractory period (see Note).
E_ex         mV     Excitatory synaptic reversal potential
E_in         mV     Inhibitory synaptic reversal potential
E_Na         mV     Sodium reversal potential
g_Na         nS     Sodium peak conductance
E_K          mV     Potassium reversal potential
g_K          nS     Potassium peak conductance
I_e          pA     External input current
=========== ======  =========================================================

References
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.. [1] Brette R et al. (2007). Simulation of networks of spiking neurons: A
       review of tools and strategies. Journal of Computational Neuroscience
       23:349-98. DOI: https://doi.org/10.1007/s10827-007-0038-6
.. [2] Traub RD and Miles R (1991). Neuronal networks of the hippocampus.
       Cambridge University Press, Cambridge UK.
.. [3] http://modeldb.yale.edu/83319

Sends
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SpikeEvent

Receives
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SpikeEvent, CurrentEvent, DataLoggingRequest

See also
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:doc:`Neuron <index_neuron>`, :doc:`Hodgkin-Huxley <index_Hodgkin-Huxley>`, :doc:`Conductance-Based <index_conductance-based>`