“Neuronal identification of acoustic communication cues”
Anna Magnusson, PhD
Associate Professor, Senior Lecturer
Auditory Research Group
CLINTEC, Karolinska Institutet
The temporal structure of slow sound amplitude fluctuations (sound envelope) is an important cue for the perception of complex acoustic stimuli. For instance, perception of human speech relies heavily on accurate processing of the sound envelope. The neuronal mechanisms by which the sound envelope is extracted and conveyed to higher auditory areas are unknown.
The Superior Paraolivary Nucleus (SPON) is a prominent structure in the mammalian auditory brainstem, which is characterized by its ability to fire with high precision to the sound envelope or sound gaps. I will present results which reveal how SPON neurons are equipped to accomplish this task. Using a combination of electrophysiology and mathematical modelling, we show that interplay between four ion channels tune these neurons to extract temporal information contained in behaviorally relevant communication sounds. Subtle differences in the channel combinations creates variability that ensures coverage of the entire temporal register but that emphasizes tuning for species-specific calls This is an example of how the brain transforms a temporal pattern of periodic signals into a neural representation of the acoustic envelope, important for perceiving speech and music.