Periodic Reporting for period 1 - VocalBrain (Whole-brain neural dynamics of vocal-auditory interactions in the sound-producing, transparent vertebrate Danionella translucida)
Berichtszeitraum: 2021-09-01 bis 2023-08-31
The auditory system can separate between external sounds and sounds that are self-generated through an animal’s movement or vocalization. While some of the mechanisms of how the brain makes this distinction are known, the current understanding is incomplete, especially how these processes play out along the auditory path – from the ear to the higher auditory processing centers in the brain. To date the only technique to study neural activity across the whole brain at a single-cell level is via light measurements, so called calcium imaging. Yet for this method to be applicable the animal model needs to be transparent for light to enter the brain and small enough to measure the whole brain under a microscope. Danionella cerebrum (DC, formerly known as Danionella translucida) is a new model in neurosciences that fulfils these criteria, as this transparent fish has the smallest known adult vertebrate brain. Additionally, DC produce audible click sounds during social communication. Therefore, the VocalBrain project aims at establishing DC as a model for whole-brain measurements of auditory-vocal interactions. Such a model will allow us to perform novel experiments and ask mechanistic questions about how the brain processes its own and external sounds.
The VocalBrain project characterized the sound production system in DC, including the drumming muscle and the vocal-motor neurons. To this end, neural tracing protocols were developed and in situ hybridization of various brain markers was performed to improve the knowledge of DC’s brain anatomy. Finally, a setup was implemented to target and measure vocal stimulations under a two-photon microscope. Dissemination of the project includes presentation to the public at the European research nights and science slams, as well as scientific presentations at international meetings and upcoming publication in peer-reviewed journals.
The VocalBrain project helps to establish DC as a model for whole-brain measurements of auditory-vocal interactions by providing essential information on DC anatomy and tracing techniques. These results will help other researchers take advantage of DC’s unique suitability for large-scale neuroscience questions that span the brain.