SPARC: Development of Human and Rodent Neuro‐Functionalized Computational Anatomical Models with Detailed Mapping of Peripheral Nervous System

Abstract

There is a growing trend within the neuroscience community and the medical and health industries towards bioelectronics medicine: applying electrical signals to the nervous system to control and modulate functions of the body. These so‐called “electroceuticals” include numerous types of neurostimulation devices. To this end, we have developed reference animal and human anatomical models with unprecedented details in the peripheral nervous system, and connectivity to organs and muscles, which were functionalized with compartmental neuronal dynamics models to investigate device interactions with neuronal electrophysiology. The whole body rat model is being segmented from co‐registered high‐resolution (80 × 80 × 80 μm) magnetic resonance imaging (MRI) and computed tomography (CT) images of a female rat. The Visible Korean Human (1) male and female cryosection data was used as the basis for the new human phantoms, due to the unique resolution (0.1 × 0.1 × 0.2 mm) and quality of these images. To model important peripheral nerves trajectories, the nerves were segmented and anatomically correct trajectories were extracted automatically using a set of anatomical rules specifying, which dorsal or ventral roots are connected to a given nerve. Functionalization is achieved by assigning electrophysiological models of myelinated and unmyelinated axons to axon trajectories within nerve models based on histological investigations documented in the literature (2).The new human female and male human models called Yoon‐sun and Jeduk respectively, have been released as part of the Virtual Population (3) V4.0 model library. The neuro‐functionalized rat will be completed soon. These models will become integration centers for NIH SPARC neuroanatomy and electrophysiology models (4) and are expected to significantly influence the field of computational neuro‐electrophysiology research enabling studies of multi‐scale models with realistic anatomies and electrophysiology. Simulations will enhance our understanding of mechanisms of neurostimulation, e.g., by MRI gradient fields, provide experimental test‐beds for new therapeutic approaches and devices, and enable study of safety aspects, thus providing a tool to facilitate regulatory submissions and standardization activities.Support or Funding InformationThis work has been done with funding from NIH SPARC (1OT3OD025348‐01S1). The work on human anatomical models also received funding from Innosuisse (25290.1 PFLS‐LS) and KIAT.Computational rat model is shown with muscle tissue and limbs clipped to show interior tissue structures.Figure 1Side‐by‐side visualization of different tissue structures in the female computational human anatomical model ‘Yoon‐sun’. The model contains approximately 1100 separate tissues, with detailed bones, organs, muscles, blood vessels and peripheral nervous system (right).Figure 2