title: Behavioral relevance helps untangle natural vocal categories in a specific subset of core auditory cortical pyramidal neurons.
abstract: Sound categorization is essential for auditory behaviors like acoustic communication, but its genesis within the auditory pathway is not well understood-especially for learned natural categories like vocalizations, which often share overlapping acoustic features that must be distinguished (e.g., speech). We use electrophysiological mapping and single-unit recordings in mice to investigate how representations of natural vocal categories within core auditory cortex are modulated when one category acquires enhanced behavioral relevance. Taking advantage of a maternal mouse model of acoustic communication, we found no long-term auditory cortical map expansion to represent a behaviorally relevant pup vocalization category-contrary to expectations from the cortical plasticity literature on conditioning with pure tones. Instead, we observed plasticity that improved the separation between acoustically similar pup and adult vocalization categories among a physiologically defined subset of late-onset, putative pyramidal neurons, but not among putative interneurons. Additionally, a larger proportion of these putative pyramidal neurons in maternal animals compared with nonmaternal animals responded to the individual pup call exemplars having combinations of acoustic features most typical of that category. Together, these data suggest that higher-order representations of acoustic categories arise from a subset of core auditory cortical pyramidal neurons that become biased toward the combination of acoustic features statistically predictive of membership to a behaviorally relevant sound category.
authors: Graduate Program in Neuroscience, Department of Biology, and.
authors: Kathryn N
authors: KN
authors: Shepard
authors: Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia 30332.
authors: Frank G
authors: FG
authors: Lin
authors: Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia 30332.
authors: Charles L
authors: CL
authors: Zhao
authors: Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia 30332.
authors: Kelly K
authors: KK
authors: Chong
authors: Department of Biology, and Center for Translational Social Neuroscience, Emory University, Atlanta, Georgia 30322, and robert.liu@emory.edu.
authors: Robert C
authors: RC
authors: Liu
mesh_terms: D000161:Acoustic Stimulation; D000818:Animals; D001303:Auditory Cortex / Q000166:cytology / Q000502:physiology*; D001522:Behavior, Animal / Q000502:physiology*; D005260:Female; D006309:Hearing / Q000502:physiology; D051379:Mice; D008808:Mice, Inbred CBA; D009473:Neuronal Plasticity / Q000502:physiology; D017966:Pyramidal Cells / Q000502:physiology*; D059629:Signal-To-Noise Ratio; D014465:Ultrasonics; D014828:Vocalization, Animal / Q000502:physiology*
keywords: auditory object; categorization; communication; map plasticity; neural coding; ultrasonic vocalization