Fellows Lecture in Pairs: “Hearing in an acoustically complex world” and "Heart regeneration in the Mexican cavefish"

Associate Professor Kerry Walker: “Hearing in an acoustically complex world”

The early auditory system decomposes incoming sounds into a collection of sine waves with different frequencies. But we would not describe our everyday experience of hearing as one of “perceiving frequencies”. Rather, we experience more behaviourally relevant features of complex auditory objects, such as the pitch of a voice singing a familiar melody. The brain derives these higher-level perceptual features by integrating information across frequency channels through a number of specialized algorithms. Furthermore, the brain’s algorithms must be robust enough to extract these characteristic features even though the actual acoustics of the sound can change dramatically in the real world, allowing us to recognize the same song sung by different people, whether they are sitting in a cathedral, a busy café, or a quiet sitting room. I will discuss some of our behavioural, electrophysiological and 2-photon imaging studies that uncover how neurons in auditory cortex master these challenges of listening in an acoustically complex world.

Kerry Walker Biography:

Kerry studied her BSc and MSc in Neuroscience in Canada before moving to Oxford to complete her DPhil in DPAG with Prof Andrew King and Prof Jan Schnupp. She started her own research group in DPAG as an Early Career Research Fellow and is now an Associate Professor in Neuroscience. Her group uses behavioural, electrophysiological and 2-photon imaging methods to examine auditory function in ferrets and mice, and has recently begun investigating age-related hearing loss in humans.

Associate Professor Mathilda Mommersteeg: “Heart regeneration in the Mexican cavefish”

Heart regeneration potential varies considerably between species, but also within species. While Astyanax mexicanus surface fish regenerate their heart after injury, their Pachón cave-dwelling counterparts cannot and form a permanent fibrotic scar, similar to the human heart. This difference in cardiac regeneration capacity within the same species provides a valuable new heart regeneration research model. Our research focusses on discovering the mechanisms underlying the difference in heart regeneration capacity between the two fish. Comparing the injury response in Astyanax mexicanus not only allows us to directly compare the cellular and molecular differences between scarring versus regeneration, it also uniquely allows us to perform Quantitative Trait Locus (QTL) to identify the key genes controlling heart regeneration. We have identified crucial differences in metabolism as well as the immune and scarring response as main causes underlying the difference in regeneration. Understanding the principles and mechanisms that promote, or prevent, effective cardiac regeneration in Astyanax mexicanus will allow us to find therapeutic targets to improve cardiac repair in patients.

Mathilda Mommersteeg Biography:

Mathilda Mommersteeg obtained her PhD in 2009 from the University of Amsterdam, where she worked in the laboratories of Prof. Vincent Christoffels and Prof. Antoon Moorman on the development of the conduction system and venous pole of the mammalian heart. In 2010, she joined the laboratory of Prof. John Parnavelas at UCL, where her work focused on deciphering the roles of the Slit-Robo signalling pathway during mammalian heart development. While at UCL, she set up a project researching heart regeneration in Mexican cavefish together with Dr. Yoshiyuki Yamamoto. Both projects form the basis for the research in her lab in Oxford, investigating the molecular mechanisms underlying heart regeneration and development.