hh_psc_alpha_clopath – Hodgkin-Huxley neuron model with support for Clopath plasticity ====================================================================================== Description +++++++++++ ``hh_psc_alpha_clopath`` is an implementation of a spiking neuron using the Hodgkin-Huxley formalism and that is capable of connecting to a Clopath synapse. (1) Postsynaptic currents Incoming spike events induce a postsynaptic change of current modelled by an alpha function. The alpha function is normalized such that an event of weight 1.0 results in a peak current of 1 pA. (2) Spike Detection Spike detection is done by a combined threshold-and-local-maximum search: if there is a local maximum above a certain threshold of the membrane potential, it is considered a spike. See also [1]_, [2]_, [3]_, [4]_, [5]_, [6]_. Parameters ++++++++++ The following parameters can be set in the status dictionary. =========== ====== =================================================== **Dynamic state variables** ----------------------------------------------------------------------- V_m mV Membrane potential u_bar_plus mV Low-pass filtered Membrane potential u_bar_minus mV Low-pass filtered Membrane potential u_bar_bar mV Low-pass filtered u_bar_minus =========== ====== =================================================== =========== ====== =========================================================== **Membrane Parameters** ------------------------------------------------------------------------------- E_L mV Leak reversal potential C_m pF Capacity of the membrane 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 E_Na mV Sodium reversal potential g_Na nS Sodium peak conductance E_K mV Potassium reversal potential g_K nS Potassium peak conductance Act_m real Activation variable m Inact_h real Inactivation variable h Act_n real Activation variable n I_e pA External input current =========== ====== =========================================================== ============= ======= ======================================================= **Clopath rule parameters** ----------------------------------------------------------------------------- A_LTD 1/mV Amplitude of depression A_LTP 1/mV^2 Amplitude of facilitation theta_plus mV Threshold for u theta_minus mV Threshold for u_bar_[plus/minus] A_LTD_const boolean Flag that indicates whether `A_LTD_` should be constant (true, default) or multiplied by u_bar_bar^2 / u_ref_squared (false). delay_u_bars real Delay with which u_bar_[plus/minus] are processed to compute the synaptic weights. U_ref_squared real Reference value for u_bar_bar_^2. ============= ======= ======================================================= Problems/Todo +++++++++++++ - better spike detection - initial wavelet/spike at simulation onset References ++++++++++ .. [1] Gerstner W and Kistler WM (2002). Spiking neuron models: Single neurons, populations, plasticity. New York: Cambridge university press. .. [2] Dayan P and Abbott L (2001). Theoretical Neuroscience: Computational and Mathematical Modeling of Neural Systems. Cambridge, MA: MIT Press. https://pure.mpg.de/pubman/faces/ViewItemOverviewPage.jsp?itemId=item_3006127 .. [3] Hodgkin AL and Huxley A F (1952). A quantitative description of membrane current and its application to conduction and excitation in nerve. The Journal of Physiology 117. DOI: https://doi.org/10.1113/jphysiol.1952.sp004764 .. [4] Clopath et al. (2010). Connectivity reflects coding: a model of voltage-based STDP with homeostasis. Nature Neuroscience 13(3):344-352. DOI: https://doi.org/10.1038/nn.2479 .. [5] Clopath and Gerstner (2010). Voltage and spike timing interact in STDP – a unified model. Frontiers in Synaptic Neuroscience. 2:25 DOI: https://doi.org/10.3389/fnsyn.2010.00025 .. [6] Voltage-based STDP synapse (Clopath et al. 2010) connected to a Hodgkin-Huxley neuron on ModelDB: https://senselab.med.yale.edu/ModelDB/showmodel.cshtml?model=144566&file =%2fmodeldb_package%2fstdp_cc.mod Sends +++++ SpikeEvent Receives ++++++++ SpikeEvent, CurrentEvent, DataLoggingRequest See also ++++++++ :doc:`Neuron `, :doc:`Hodgkin-Huxley `, :doc:`Current-Based `, :doc:`Clopath Plasticity `