Morris-Lecar Neuron

The Morris Lecar neuron model (also see this Scholarpedia article) is a 2-dimensional neuron model which models neural dynamics based on calcium and potassium conductances. A simplification of Hodgkin-Huxley dynamics without the sodium channels. Potassium and calcium can capture many of the core dynamics.

Part of a family of 2-variable neuron activation models.

As a family tree, Hodgkin-Huxley came first, then FitzHugh-Nagumo, then Morris-Lecar

Membrane potential is what shows as activation.

Parameter descriptions are given here though it may help to simply think of these as the parameters of a complex dynamical system. More detailed description of similar parameters are in the AdEx docs.

Membrane Properties

Capacitance (µF/cm²): Behaves like a time constant. Higher capacitance leads to slower changes in the cell.


Voltage const. 1: How does calcium respond to voltage.


Voltage const. 2: How does calcium respond to voltage.


Threshold (mV): voltages above this make the neuron spike.


Background current (nA): A constant level of current that can be set.


Add Noise: Whether to add noise to

Ion Properties

Ca2+ Conductance (µS): Calcium conductance. If higher, voltage pulled more quickly to Ca2+ equilibrium.


K+ Conductance (µS): Potassium conductance. If higher, voltage pulled more quickly to K+ equilibrium.


Leak Conductance (µS): Leak conductance. If higher, voltage pulled more quickly to Leak equilibrium.


Ca2+ Equilibrium (mV): Calcium equilibrium.


K+ Equilibrium (mV): Potassium equilibrium.


Leak Equilibrium (mV): Leak equilibrium.

K+ Consts.

K+ Const. 1: V3 on the Scholarpedia page, which roughly corresponds to how potassium current responds to membrane voltage.


K+ Const. 2: V4 on the Scholarpedia page.


K+φ: Potassium channel time constant/decay rate. If higher, potassium changes more slowly.

Noise

See here.