Johns Hopkins School of Medicine

We use a combination of single-cell transcriptomic analysis, animal models, virus-mediated axon tracing and in vivo electrophysiology to identify the molecules and mechanisms mediating correct neural circuit formation and organization.

 

We focus on understanding these processes in the central auditory system, a network in which the function is disrupted in neurodevelopmental disorders and in which it remains unclear how these specific connections are established.

 

When we hear a sound, we almost instantaneously recognize the frequency and physical location of that sound. How does the brain do this?

Sound is first detected by the cochlea, and auditory information is sent to the brainstem, where it is processed through a series of distinct neural pathways that enable properties such as frequency and location to be decoded.

To process the frequency of sound, the brain uses tonotopic maps, which are the spatial organization of how sounds with different physicalfrequencies are represented in all auditory regions.

Tonotopic connections are formed between neurons of different auditory processing regions. Neurons that are tuned to similar frequencies are connected with each other. This ensures that information about sound frequency is accurately represented in all auditory brain regions.

The formation of tonotopic connections begins early in brain development, before we can even hear, and this organization is later refined during a critical period that occurs at the onset of hearing.

We are investigating the mechanisms that are important at both stages of development for the correct formation of tonotopic maps and how these processes are disrupted in neurodevelopmental disorders such as autism.