The provided code models the fast sodium (Na+) current in thalamocortical neurons, a specific type of neuron connecting the thalamus to the cortex in the brain. This model is based on the implementation suggested by Meijer et al., 2011, and was written by Xu Zhang in 2018. Below are the key biological concepts relevant to this model:
m_na
for activation and h_na
for inactivation) to simulate the dynamics of the sodium channels' opening and closing.
m_na
represents the probability of the channel being in an open state, which is affected by the membrane potential (v
).h_na
represents the inactivation gate, which modulates how quickly the channels close post-activation.alpham
, betam
) and inactivation (alphah
, betah
) kinetics, which determine how the gating variables change over time, and ultimately how the sodium current (ina
) changes in response to membrane voltage changes.gbar
): Represents the maximum possible conductance of the sodium channels measured in siemens per square centimeter. It indicates the density of sodium channels within the membrane and affects the magnitude of the sodium current.ena
): The reversal potential for sodium ions, around which the driving force for the sodium current is calculated. This potential is crucial for determining the direction and amplitude of the current flow.In summary, this code simulates the biophysical behavior of fast sodium channels in thalamocortical neurons using a theoretical framework that captures the dynamics of activation and inactivation in the context of neuronal signaling and action potential generation.