A joint study from URV and the University of Berkeley is studying zebrafish hearing.

The research team has established an experimental method that allows us to non-invasively study how differences in anatomical arrangements affect their behavior.

URV researcher Jordi Marce-Noguet and UC Berkeley researcher Juan Liu worked together to analyze the behavior of the bones of the Weber’s apparatus – part of the auditory system – of the zebrafish (Zebrafish). They confirmed that the resonant frequency of fish ear bones matches their audible spectrum and that the behavior of these small bones does not change depending on their size. Their research allowed them to develop a method for non-invasive study of anatomical structures, allowing them to understand and study the human body. The results were published in the journal Interfacefrom the Royal Society of London.

The Weber system is part of the zebrafish’s auditory system and connects the zebrafish’s inner ear to the swim bladder, a buoyancy organ found in many fish and cetaceans. “The analogy between some human organs and the organs of these animals has made them a popular subject of study recently,” explains Marcé-Noguet, a postdoctoral fellow in the Department of Mechanical Engineering. Thus, discoveries about this species may be useful for better understanding the functioning of organs in the human body or for achieving medical advances.

Marcé-Noguet and Liu developed a three-dimensional virtual model of the system’s ossicular array based on previous studies and consolidated anatomical models. This virtual model was subjected to audio sweeping in a simulation using the finite element method, a computational method commonly used in mechanical engineering. That is, the vibration of bones has been studied depending on the frequency of the sound source affecting them. These vibrations are transmitted in bodies and cause them to vibrate to a greater or lesser extent depending on the material from which they are made and their structure. This analysis determined that the resonant frequency of the ossicles, that is, the frequency at which the bones vibrate most intensely, matches the audible spectrum of these animals. In parallel, they created ten models, changing the size of the bones, and repeated the experimental method. The results show that the resonant frequency does not change depending on the size of the bones, but will depend on other factors of their nature.

The study conducted by Marcé-Noguet and Liu validated a methodological model that allows virtual experiments based on anatomical models. According to Marse-Noguet, this allows us to non-invasively study how changes in anatomical structures affect their behavior, either because certain organs cannot be accessed or because they do not exist at all.

Link: Marce-Noguet Jordi & Liu Huang, 2024. Finite element modeling of sound transmission in the zebrafish Weber apparatus (Danio Rerio). R. Social Interface. 21: 20230553. 20230553. http://doi.org/10.1098/rsif.2023.0553.