A media alert for the journal Current Biology.
EMBARGOED RELEASE
Media Contact: Joseph Caputo | Press Office | Cell Press
617-397-2802 | jcaputo@cell.com | press@cell.com
STRICTLY UNDER EMBARGO UNTIL 12:00PM NOON ET (US) ON MONDAY, MAY 4, 2015
These gigantic whales have
nerves like bungee cords
Nerves aren't known for being
stretchy. In fact, "nerve stretch
injury" is a common form of
trauma in humans. But
researchers reporting in the Cell
Press journal Current Biology on
May 4 have discovered that
nerves in the mouths and tongues
of rorqual whales can more than double their length with no trouble at all.
"These large nerves actually stretch and recoil like bungee cords," says A. Wayne Vogl of the
University of British Columbia. "This is unlike other nerves in vertebrates, where the nerve is of a
more fixed length that has enough slack in it to accommodate changes in position of the structures
the nerves are supplying."
Those stretchy nerves support the animals' unique and extreme lunge feeding strategy, which helps
to support the whales' gigantic bodies.
Rorqual whales represent the largest group among baleen whales, weighing in at an impressive 40 to
80 tons. To eat, the whales open their mouths and lunge while their tongues invert and their mouths
fill like giant water balloons full of floating prey. Those prey are concentrated by slowly expelling the
water through baleen plates. The volume of water brought in with a single gulp can exceed the
volume of the whale itself.
"Rorqual whales attained large body size with the evolution of a bulk filter feeding mechanism based
on engulfing huge volumes of prey-laden water," Vogl says. "This required major changes in anatomy
of the tongue and ventral blubber to allow large deformation, and now we recognize that this also
required major modifications in the structure of nerves in these tissues so they could withstand the
tissue deformation."
Vogl and his team hadn't expected this at all. They made the discovery after a member of the lab
picked up a dull white cord-like structure and stretched it. Vogl recalls him saying something like,
"Wow, look at this."
It looked like a blood vessel, which ought to be stretchy. But they realized upon closer inspection that
it was a nerve -- one unlike any they'd ever seen before. The nerves of other species are generally
surrounded by a thin collagen wall, and any stretch can pull and damage the nerves.
What the researchers see in these whales is something entirely different. The nerve fibers themselves
are packaged inside a central core; they don't stretch so much as unfold. A very thick and stretchy
outer wall full of elastin fibers that Vogl likens to elastic bands surrounds that nerve core.
The researchers don't know yet whether anything similar will turn up in other animals -- the ballooning
throats of frogs, for example, or the long and fast tongues of chameleons. They plan to keep studying
the whales' nerves in greater detail, in hopes of understanding better how the nerve core is folded in
such a way to allow its rapid unpacking and re-packing as the entire structure is stretched and then
relaxed again.
###
Current Biology, Vogl et al.: "Stretchy nerves are an essential component of the extreme feeding
mechanism of rorqual whales" http://dx.doi.org/10.1016/j.cub.2015.03.007
In online coverage, please mention the journal Current Biology and link to the paper
at http://www.cell.com/current-biology/abstract/S0960-9822(15)00284-5
To access a PDF of the paper proof, the supplemental data, and two images (Credit: Vogl et
al./Current Biology 2015), please visit this
Dropbox: https://www.dropbox.com/sh/m6rz9kaee32jb12/AAB_xtmdLwtJclnNAj2fPtUWa?dl=0 or email Joseph Caputo at jcaputo@cell.com.
Author Contacts:
A. Wayne Vogl
University of British Columbia
vogl@mail.ubc.ca
Mobile: 604-315-5685
Robert Shadwick
University of British Columbia
shadwick@zoology.ubc.ca
Office: 604-827-3149
Media Contact:
Chris Balma
Director, Communications
UBC Faculty of Science
Office: 604-822-5082
Mobile: 604-202-5047
cebalma@mail.ubc.ca
IMAGES
Image 1:
Caption
To eat, rorqual whales open their mouths and lunge while their tongues invert and their
mouths fill like giant water balloons full of floating prey. The whales' nerves are stretchy so
they can withstand the tissue deformation.
Credit
Vogl et al./Current Biology 2015
Usage Restrictions
Credit Required.
Image 2:
Caption
Segment of a nerve of the rorqual whale tongue at its initial length prior to being stretched
(top left). The nerve has been manually stretched until it abruptly stiffens and resists further
extension, and is more than twice its initial length (bottom).
Credit
Vogl et al./Current Biology 2015
Usage Restrictions
Credit Required.