Brain-wide processing of auditory cues for sound source segregation

• Applicant: Dr. Jörg Henninger
• Subject Area: Experimental and Theoretical Network Neuroscience ; Cognitive, Systems and Behavioural Neurobiology
• Term: since 2025
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 556982588

Sound is highly informative about environmental events, even those that cannot be seen or occur at large distances. Yet, although sounds from many sources reach our ears as a single mixture, we somehow perceive these sounds as being distinct entities that each have their own properties. This ability to perceptively segregate sounds has been demonstrated across vertebrates in humans, monkeys, birds and fish. While these phenomena have been studied extensively on the behavioral level in humans and to a lesser extent in non-human vertebrates, our mechanistic understanding of these processes is extremely limited. The reasons for this are two-fold: first, identifying candidate circuits is challenging, because most vertebrate brains are large and highly opaque, rendering them inaccessible to an unbiased, system-wide investigation. Second, identifying candidates alone would not be sufficient: one also needs to demonstrate that they play a central role in shaping a listener's auditory perception – a feat that has not been achieved in any species to date. In order to address these challenges, I recently introduced the teleost fish Danionella cerebrum as a unique vertebrate model into neuroscience. Danionella remain transparent throughout their lifespan and are fully accessible to brain-wide imaging and optogenetic manipulations. Despite their small size, they display complex behaviors, including acoustic communication. Here, I will exploit this model to (1) determine Danionella's auditory perceptual capacity regarding source segregation, (2) identify candidate circuits with behavior- correlated activity using brain-wide functional imaging at single cell resolution and (3) use targeted manipulations of its neural activity in order to establish causal relationships between Danionella's auditory perception and the functioning of candidate circuits. These measurements will, for the first time, allow for an unbiased, brain-wide screen for neural correlates of auditory perception across the entire acoustic processing pathway at single cell resolution. If successful, this study will constitute a major step for our understanding of how brains make sense of complex acoustic environments.

• DFG Programme: Research Grants