title: Functional role of airflow-sensing hairs on the bat wing.
abstract: The wing membrane of the big brown bat (Eptesicus fuscus) is covered by a sparse grid of microscopic hairs. We showed previously that various tactile receptors (e.g., lanceolate endings and Merkel cell neurite complexes) are associated with wing-hair follicles. Furthermore, we found that depilation of these hairs decreased the maneuverability of bats in flight. In the present study, we investigated whether somatosensory signals arising from the hairs carry information about airflow parameters. Neural responses to calibrated air puffs on the wing were recorded from primary somatosensory cortex of E. fuscus Single units showed sparse, phasic, and consistently timed spikes that were insensitive to air-puff duration and magnitude. The neurons discriminated airflow from different directions, and a majority responded with highest firing rates to reverse airflow from the trailing toward the leading edge of the dorsal wing. Reverse airflow, caused by vortices, occurs commonly in slowly flying bats. Hence, the present findings suggest that cortical neurons are specialized to monitor reverse airflow, indicating laminar airflow disruption (vorticity) that potentially destabilizes flight and leads to stall.
  
  
  
  Bat wings are adaptive airfoils that enable demanding flight maneuvers. The bat wing is sparsely covered with sensory hairs, and wing-hair removal results in reduced flight maneuverability. Here, we report for the first time single-neuron responses recorded from primary somatosensory cortex to airflow stimulation that varied in amplitude, duration, and direction. The neurons show high sensitivity to the directionality of airflow and might act as stall detectors.
authors.affiliation: Institute for Systems Research, University of Maryland, College Park, Maryland; ssterbi1@JHU.edu.|Department of Psychological and Brain Sciences, Johns Hopkins University, Baltimore, Maryland; and.
authors.forename: S J
authors.initials: SJ
authors.lastname: Sterbing-D'Angelo
authors.affiliation: Program in Neuroscience and Cognitive Science, University of Maryland, College Park, Maryland.|Department of Psychology, University of Maryland, College Park, Maryland.|Department of Psychological and Brain Sciences, Johns Hopkins University, Baltimore, Maryland; and.
authors.forename: M
authors.initials: M
authors.lastname: Chadha
authors.affiliation: Departments of Dermatology and Physiology and Cellular Biophysics, Columbia University, New York, New York.
authors.forename: K L
authors.initials: KL
authors.lastname: Marshall
authors.affiliation: Institute for Systems Research, University of Maryland, College Park, Maryland.|Program in Neuroscience and Cognitive Science, University of Maryland, College Park, Maryland.|Department of Psychology, University of Maryland, College Park, Maryland.|Department of Psychological and Brain Sciences, Johns Hopkins University, Baltimore, Maryland; and.
authors.forename: C F
authors.initials: CF
authors.lastname: Moss
mesh_terms: D000200:Action Potentials / Q000502:physiology; D000818:Animals; D002685:Chiroptera / Q000502:physiology*; D005426:Flight, Animal / Q000502:physiology*; D006197:Hair / Q000502:physiology* / Q000648:ultrastructure; D008855:Microscopy, Electron, Scanning; D010812:Physical Stimulation; D011984:Sensory Receptor Cells / Q000502:physiology* / Q000648:ultrastructure; D013003:Somatosensory Cortex / Q000166:cytology*; D014110:Touch; D055698:Touch Perception / Q000502:physiology*; D014921:Wings, Animal / Q000502:physiology* / Q000648:ultrastructure
keywords: bat; electrophysiology; somatosensory cortex; tactile sensing; wing