title: On-going computation of whisking phase by mechanoreceptors.
abstract: To attribute spatial meaning to sensory information, the state of the sensory organ must be represented in the nervous system. In the rodent's vibrissal system, the whisking-cycle phase has been identified as a key coordinate, and phase-based representation of touch has been reported in the somatosensory cortex. Where and how phase is extracted in the ascending afferent pathways remains unknown. Using a closed-loop interface in anesthetized rats, we found that whisking phase is already encoded in a frequency- and amplitude-invariant manner by primary vibrissal afferents. We found that, for naturally constrained whisking dynamics, such invariant phase coding could be obtained by tuning each receptor to a restricted kinematic subspace. Invariant phase coding was preserved in the brainstem, where paralemniscal neurons filtered out the slowly evolving offset, whereas lemniscal neurons preserved it. These results demonstrate accurate, perceptually relevant, mechanically based processing at the sensor level.
authors.affiliation: Department of Neurobiology, Weizmann Institute of Science, Rehovot, Israel.|Present address: Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada.
authors.forename: Avner
authors.initials: A
authors.lastname: Wallach
authors.affiliation: Department of Neurobiology, Weizmann Institute of Science, Rehovot, Israel.
authors.forename: Knarik
authors.initials: K
authors.lastname: Bagdasarian
authors.affiliation: Department of Neurobiology, Weizmann Institute of Science, Rehovot, Israel.
authors.forename: Ehud
authors.initials: E
authors.lastname: Ahissar
mesh_terms: D000344:Afferent Pathways / Q000502:physiology*; D000818:Animals; D001933:Brain Stem / Q000502:physiology; D008297:Male; D008465:Mechanoreceptors / Q000502:physiology*; D051381:Rats; D012668:Trigeminal Ganglion / Q000502:physiology; D014738:Vibrissae / Q000502:physiology*