Closed-loop baroreflex model with biophysically detailed afferent pathway

Author(s)

Fernandes, Luciano Goncalves ; Mueller, Lucas Omar ; Feijoo, Raul Antonino ; Blanco, Pablo Javier

• Document type: Journal article
• Source: INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING; v. 40, n. 9, p. 59-pg., 2024-07-25.

Abstract

In this work, we couple a lumped-parameter closed-loop model of the cardiovascular system with a physiologically-detailed mathematical description of the baroreflex afferent pathway. The model features a classical Hodgkin-Huxley current-type model for the baroreflex afferent limb (primary neuron) and for the second-order neuron in the central nervous system. The pulsatile arterial wall distension triggers a frequency-modulated sequence of action potentials at the afferent neuron. This signal is then integrated at the brainstem neuron model. The efferent limb, representing the sympathetic and parasympathetic nervous system, is described as a transfer function acting on heart and blood vessel model parameters in order to control arterial pressure. Three in silico experiments are shown here: a step increase in the aortic pressure to evaluate the functionality of the reflex arch, a hemorrhagic episode and an infusion simulation. Through this model, it is possible to study the biophysical dynamics of the ionic currents proposed for the afferent limb components of the baroreflex during the cardiac cycle, and the way in which currents dynamics affect the cardiovascular function. Moreover, this system can be further developed to study in detail each baroreflex loop component, helping to unveil the mechanisms involved in the cardiovascular afferent information processing. This study integrates a biophysical Hodgkin-Huxley model of the baroreflex afferent pathways with a lumped cardiovascular system model, forming a closed-loop system. This novel approach allows for detailed analysis of baroreflex dynamics, including ionic currents and synaptic interactions. The composite model mimics cardiovascular regulation and can be used to explore neurotransmitter dynamics and potential links to diseases like hypertension. image (AU)

• FAPESP's process: 14/50889-7 - National Institute of Science and Technology Medicine Assisted by Scientific Computing (INCT-MACC)
• Grantee: José Eduardo Krieger
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 18/14221-2 - Coronary bifurcations geometry: an exploratory study of the mathematical laws to estimate the vascular dimensions in coronary bifurcations
• Grantee: Gabriela Hidalgo Vargas dos Santos
• Support Opportunities: Scholarships in Brazil - Scientific Initiation