Gunnar Quass, PhD
Postdoctoral Fellow, Department of Otolaryngology, University of Michigan
Auditory Midbrain Activity Encodes Behavioral Choice
During behavior, neural activity of thalamo-cortical systems often reflects dynamic combinations of sensory and task-dependent variables, and these “mixed representations” are suggested to be important for perception, learning, and plasticity. However, the extent to which such integrative computations might occur also in lower-order brain regions is less clear. We conducted cellular-resolution 2-photon Ca2+ imaging in the inferior colliculus (IC), as head-fixed mice performed a reward-based psychometric auditory task. We find that the activity of individual shell IC neurons jointly reflects auditory cues, mice’s actions, and behavioral trial outcomes, such that neural population activity indicates mice’s behavioral choice. Consequently, simple classifier models trained on IC neuron activity can predict trial-by-trial outcomes. Thus, in behaving mice, auditory midbrain neurons transmit a population code that reflects a joint representation of sound, actions, and task-dependent variables, adding the IC as an important puzzle piece for perceptual learning circuits and auditory-guided behavior.