The action potential is perhaps the most characteristic phenomenon exhibited by neurons. It is at the basis of neuronal exicitability, the very reason they are called excitable cells.
Membrane Capacitance
It is a measure of the lipid bilayer’s ability to store charge, with values for different neuron types typically ranging from 0.5 to 1.0 μF/cm².
Reverse potential of ions
- Sodium $Na$:
- Potassium $K$:
- Calcium $Ca$:
Ionic currents commonly used in neuron models
Sodium current $I_{Na}$
Delayed rectifier potassium current $I_{Kdr}$
Leakage current $I_L$
This represents the hyperpolarizing current driving the membrane potential to its resting value. It is not ion-specific.
A-type potassium current $I_A$
Muscarinic-sensitive potassium current $I_M$
Persistent sodium current $I_{NaP}$
Definition:
$ I_{\text{NaP}} = g_{\text{NaP}} p_\infty (V) (V - V_{\text{Na}}) $
$ p_\infty (V) = \frac{1}{1 + e^{-\frac{V - \theta_{\text{NaP}}}{\sigma_{\text{NaP}}}}} $