Bats are masters of flight in the night sky, capable of steep nosedives and sharp turns that put our best aircrafts to shame. Although the role of echolocation in bats' impressive midair maneuvering has been extensively studied, the contribution of touch has been largely overlooked.
A study published April 30 in Cell Reports shows, for the first time, that a unique array of sensory receptors in the wing provides feedback to a bat during flight. The findings also suggest that neurons in the bat brain respond to incoming airflow and touch signals, triggering rapid adjustments in wing position to optimize flight control.
"This study provides evidence that the sense of touch plays a key role in the evolution of powered flight in mammals," says co-senior study author Ellen Lumpkin, a Columbia University associate professor of dermatology and physiology and cellular biophysics.
"This research also lays the groundwork for understanding what sensory information bats use to perform such remarkable feats when flying through the air and catching insects. Humans cannot currently build aircrafts that match the agility of bats, so a better grasp of these processes could inspire new aircraft design and new sensors for monitoring airflow."
Bats must rapidly integrate different types of sensory information to catch insects and avoid obstacles while flying. The contribution of hearing and vision to bat flight is well established, but the role of touch has received little attention since the discovery of echolocation.
Recently, co-senior study author Cynthia Moss and co-author Susanne Sterbing-D'Angelo of The Johns Hopkins University discovered that microscopic wing hairs stimulated by airflow, are critical for flight behaviors such as turning and controlling speed. But until now, it was not known how bats use tactile feedback from their wings to control flight behaviors.
In the new study, the Lumpkin and Moss labs analyzed, for the first time, the distribution of different sensory receptors in the wing and the organization of the wing skin's connections to the nervous system. Compared to other mammalian limbs, the bat wing has a unique distribution of hair follicles and touch-sensitive receptors, and the spatial pattern of these receptors suggests that different parts of the wing are equipped to send different types of sensory information to the brain.
"While sensory cells located between the "fingers" could respond to skin stretch and changes in wind direction, another set of receptors associated with hairs could be specialized for detecting turbulent airflow during flight," says Sterbing-D'Angelo, who also holds an appointment at the University of Maryland.
Moreover, bat wings have a distinct sensory circuitry in comparison to other mammalian forelimbs. Sensory neurons on the wing send projections to a broader and lower section of the spinal cord, including much of the thoracic region. In other mammals, this region of the spinal cord usually receives signals from the trunk rather than the forelimbs. This unusual circuitry reflects the motley roots of the bat wing, which arises from the fusion of the forelimb, trunk, and hindlimb during embryonic development.
"This is important because it gives us insight into how evolutionary processes incorporate new body parts into the nervous system," says first author Kara Marshall of Columbia University. "Future studies are needed to determine whether these organizational principles of the sensory circuitry of the wing are conserved among flying mammals."
The researchers also found that neurons in the brain responded when the wing was either stimulated by air puffs or touched with a thin filament, suggesting that airflow and tactile stimulation activate common neural pathways.
"Our next steps will be following the sensory circuits in the wings all the way from the skin to the brain. In this study, we have identified individual components of these circuits, but next we would like to see how they are connected in the central nervous system," Moss says. "An even bigger goal will be to understand how the bat integrates sensory information from the many receptors in the wing to create smooth, nimble flight."
The paper is titled, "Somatosensory Substrates of Flight Control in Bats." The authors are Ellen A. Lumpkin, Kara L. Marshall, Mohit Chadha, Laura A. deSouza (CUMC); Susanne J. Sterbing-D'Angelo, Cynthia F. Moss (Johns Hopkins University).
The study was funded by grants from the National Institutes of Health (R01NS073119), Air Force Office of Scientific Research (FA95501210109), and other sources listed in the paper.
The other authors declare no financial or other conflicts of interest.
Lucky Tran | EurekAlert!
Scientists uncover the role of a protein in production & survival of myelin-forming cells
19.07.2018 | Advanced Science Research Center, GC/CUNY
NYSCF researchers develop novel bioengineering technique for personalized bone grafts
18.07.2018 | New York Stem Cell Foundation
For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.
To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...
For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.
Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...
Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.
A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...
Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.
"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....
Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.
Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...
13.07.2018 | Event News
12.07.2018 | Event News
03.07.2018 | Event News
19.07.2018 | Earth Sciences
19.07.2018 | Power and Electrical Engineering
19.07.2018 | Materials Sciences