Researchers at Baylor College of Medicine and the Jan and Dan Duncan Neurological Research Institute at Texas Children’s Hospital have successfully mapped which cell populations are responsible for processing different types of sounds.

Working with a team at the Oregon Health & Science University, the Houston scientists have classified where in the cochlear nucleus our brains connect with various sounds, including speech and music. The research was published in the new edition of Nature Communications.

“Understanding these cell types and how they function is essential in advancing treatments for auditory disorders,” Matthew McGinley, assistant professor of neuroscience at Baylor, said in a release. “Think of how muscle cells in the heart are responsible for contraction, while valve cells control blood flow. The auditory brainstem operates in a similar fashion — different cell types respond to distinct aspects of sound.”

Though scientists have long thought that there are distinct types of cells in the cochlear nucleus, they didn’t have tools to distinguish them until now.

Lead author on the study, Xiaolong Jiang, associate professor of neuroscience at Baylor, added: “This study not only confirms many of the cell types we anticipated, but it also unveils entirely new ones, challenging long-standing principles of hearing processing in the brain and offering fresh avenues for therapeutic exploration.”

Jiang and his team have cooked up a comprehensive cellular and molecular atlas of the cochlear nucleus, which will help them to create more targeted and more effective treatments for patients struggling with their hearing.

The strategies that aided them in creating these tools included single-nucleus RNA sequencing, which made it possible to define neuronal populations on a molecular level. Phenotypic categorizations of the cells were made possible with patch sequencing.

This is a watershed moment for the development of targeted treatments for individuals with auditory disorders, including those with impaired function in the auditory nerve, for whom cochlear implants don’t work.

“If we can understand what each cell type is responsible for, and with the identification of new subtypes of cells, doctors can potentially develop treatments that target specific cells with greater accuracy,” McGinley explains. “These findings, thanks to the work of our collaborative team, make a significant step forward in the field of auditory research and get us closer to a more personalized treatment for each patient.”