LAUSR

Significance Several classes of auditory brain stem neurons have extremely fast membranes; they are thought to be coincidence detectors and ideal for encoding rapid temporal fluctuations of sounds. Of those neurons, octopus cells are perhaps the least understood due to recording difficulties. Here, we provide comprehensive in vivo intracellular recordings of these cells and find that contrary to the prediction of coincidence detection, they are direction selective to FM sweeps via a mechanism of sequence detection. Importantly, sequence detection and direction selectivity are recreated in a biophysical model with fast membranes. As it is a simple but powerful operation, we propose that sequence detection may be a more general mechanism to extract temporal information than coincidence detection.