The provided code is part of a computational neuroscience model focusing on simulating a biological network with elements from the autonomic nervous system (ANS), specifically targeting cardiac physiology. Here's a breakdown of the biological basis for each section of the code: ### Biological Basis 1. **Autonomic Nervous System (ANS) Component** - The code references an "ANS" directory, which suggests simulation of the autonomic nervous system's effects on heart function. The ANS regulates the heart's involuntary functions, primarily through sympathetic and parasympathetic branches. - The file `"ANS/stim_param.txt"` stores parameters, likely related to temporal aspects of autonomic modulation affecting cardiac cells. 2. **ICNS (Intrinsic Cardiac Nervous System) Simulation** - The term "ICNS" refers to the intrinsic cardiac nervous system, which governs the heart's pacemaking and conduction system. - Options to turn ICNS on or off and to specify start and end times suggest a simulation of the periods during which ICNS activity affects cardiac electrophysiology, potentially modulating heart rate and rhythms. 3. **Acetylcholine (ACh) Modulation** - The option to control "ACh On or Off" implies simulating the effects of acetylcholine, a neurotransmitter that primarily modulates heart rate via muscarinic receptors, leading to decreased heart rate and conduction velocity. - Capturing specific intervals for ACh effects may represent simulation of parasympathetic nervous activity on cardiac cells. 4. **Sanctuary Node (SAN) Analysis** - The `"SAN"` mentions suggest focus on the Sinoatrial Node, the heart's primary pacemaker. Changes in the SAN influence overall heart rhythm. - Code in this section of the model seems designed to interpret how different levels and timing of autonomic inputs affect SAN behavior, adjusting pacing dynamics accordingly. 5. **Ventricular Myocardium (VM) Examination** - The "VM" component suggests modeling the ventricular myocardium, the cardiac tissue responsible for generating forceful heart contractions. - This section would examine how outputs from SAN and autonomic inputs affect ventricular action potentials, potentially impacting contraction and timing. ### Overarching Simulation Goals - **Integration of Neural and Cardiac Models:** The model seems to integrate neural autonomic inputs with detailed cardiac electrophysiological components, aiming to replicate how the autonomic nervous system and intrinsic cardiac modulation affect heart function. - **Temporal Dynamics:** Through user-specified timings for neural modulation (e.g., ICNS, ACh), the model enables exploration of temporal dynamics on cardiac electrophysiology. - **Outcome Visualization:** The use of Python plotting scripts indicates a focus on visualizing results, likely to understand the complex interactions between neural inputs and cardiac response patterns. This model offers insights into how autonomic modulation influences cardiac physiology, critical for understanding situations like stress responses or arrhythmias influenced by neurophysiological factors.