# Incorporating buccal mass planar mechanics and anatomical features improves neuromechanical modeling of Aplysia feeding behavior

## TL;DR

Researchers improved a model of Aplysia feeding behavior by integrating detailed anatomical and mechanical features, enhancing the accuracy of simulated feeding actions.

## Contribution

A novel biomechanical model was integrated with a neural model to better simulate Aplysia feeding behaviors with improved quantitative accuracy.

## Key findings

- The model successfully reproduces three key feeding behaviors seen in Aplysia.
- Quantitative agreement was achieved for biting and swallowing behaviors.
- Further work is needed to match rejection behavior and muscle contribution observations.

## Abstract

To understand how behaviors arise in animals, it is necessary to investigate both the neural circuits and the biomechanics of the periphery. A tractable model system for studying multifunctional control is the feeding apparatus of the marine mollusk Aplysia californica. Previous in silico and in roboto models have investigated how the nervous and muscular systems interact in this system. However, these models are still limited in their ability to match in vivo data both qualitatively and quantitatively. We introduce a new neuromechanical model of Aplysia feeding that combines a modified version of a previously developed neural model with a novel biomechanical model that better reflects the anatomy and kinematics of Aplysia feeding. The model was calibrated using a combination of previously measured biomechanical parameters and hand-tuning to behavioral data. Using this model, simulated feeding experiments were conducted, and the resulting behavioral metrics were compared to animal data. The model successfully produces three key behaviors seen in Aplysia and demonstrates a good quantitative agreement with biting and swallowing behaviors. Additional work is needed to match rejection behavior quantitatively and to reflect qualitative observations related to the relative contributions of two key muscles, the hinge and I3. Future improvements will focus on incorporating the effects of deformable 3D structures in the simulated buccal mass.

The online version contains supplementary material available at 10.1007/s00422-025-01017-1.