The code provided is a computational model designed to simulate the dynamics of calcium (Ca²⁺) signaling in neurons. Calcium signaling plays a critical role in numerous cellular processes, including neurotransmitter release, muscle contraction, and various intracellular signaling pathways. The model incorporates several biological mechanisms related to calcium dynamics, including diffusion, buffering, and interactions with the endoplasmic reticulum (ER).
cai
) and extracellular calcium concentration (cao
).ica
) and its components, such as the plasma membrane calcium pump (ica_pmp
), are modeled to simulate calcium influx and efflux.ip3i
) and various other parameters like jmax
, which represents maximum flux through these channels.vmax
.TBufm
, TBufs
, KDm
, KDs
) that bind to calcium, affecting its free concentration and diffusion.Nannuli
), accounting for the spread of calcium ions through local regions and compartments.ca[Nannuli]
, bufs[Nannuli]
, etc.) to capture spatial variations in calcium dynamics.u
): A step function is used to model biological thresholds, such as the activation of pumps only above certain calcium concentrations (cath
).kon
, Kact
, Kip3
) influence the kinetics of calcium binding, release, and uptake within cellular mechanisms and structures.This NEURON-based model primarily aims to replicate and study the complex interplay of mechanisms involved in calcium signaling within neuronal cells, with emphasis on how calcium is managed, buffered, and trafficked across cellular compartments and membrane interfaces. By detailing these dynamics, the model provides insights into calcium signaling pathways critical for understanding various physiological and pathological states within neurons.