Sound changes the way rodents sense touch

Date:  December 28, 2018

Source:  Nara Institute of Science and Technology

Our eyes, ears and skin are responsible for different senses. Moreover, our brain assigns these senses to different regions: the visual cortex, auditory cortex and somatosensory cortex. However, it is clear that there are anatomical connections between these different cortices such that brain activation to one sense can influence brain activation to another. A new study by the laboratory of Associate Professor Shoji Komai at the Nara Institute of Science and Technology (NAIST), Japan, seen in PLOS ONE, explains how auditory stimulation of the barrel cortex influences responses to tactile stimulation in mice and rats.

The barrel cortex is one of the most highly studied primary somatosensory systems in animals, that is, systems in our brain sensitive to touch, pain, and temperature. It may not immediately be obvious why studying the barrel cortex, which maps sensation to whiskers, is relevant to humans, but it turns out the texture discrimination performed by the whiskers in rodents is quite similar to the same discrimination we do using our finger tips. Therefore, Komai considered the barrel cortex a good model to see how sound can affect the perception of touch.

"We think our senses are distinct, but there are many studies that show multisensory responses, mainly through audio-visual interactions or audio-tactile interactions," explains Komai.

Continued  

Deteriorating Great Barrier Reef hushed: Young fish no longer hear their way home

April 30, 2018, University of Exeter

Degraded coral reefs are far quieter than five years ago, and no longer sound like a suitable habitat to young fish searching for a place to live and breed, according to research published today in Proceedings of the National Academy of Sciences.

Baby fish looking for a home can use noisy coral reef sounds including snapping shrimp clicks, damselfish chirps, and clownfish chattering to locate and select suitable habitat. But that "coral reef orchestra" has been quietened following recent cyclone and coral-bleaching damage on the Great Barrier Reef, raising fears that young fish may no longer hear their way home.

An international team of scientists, led by the University of Exeter, carried out field experiments on the Northern Great Barrier Reef and found that reefs sound much quieter and less acoustically diverse than they did before three years of cyclones and coral bleaching.

The soundscapes of these recently-degraded reefs are less attractive to juvenile fishes attracting 40% fewer fish compared to the sound of previous healthy reefs.

Lead author Tim Gordon, a marine biologist at the University of Exeter, said: "It's heart-breaking to hear. The usual pops, chirps, snaps and chatters of countless fish and invertebrates have disappeared. The symphony of the sea is being silenced."

This loss of attractiveness of reef sounds to fish in the sea could have devastating consequences for reefs.

Fish communities are instrumental to maintaining healthy reefs by removing algae, facilitating coral growth, contributing to nutrient cycles and keeping food webs in balance. Damaged reefs with healthy fish populations recover faster than reefs that have lost their fish.

Harry Harding, co-author from the University of Bristol, explains: "If fish aren't hearing their way home anymore, that could be bad news for the recovery prospects of reefs. Fish play critical roles on coral reefs, grazing away harmful algae and allowing coral to grow. A reef without fish is a reef that's in trouble."

Read more at: 

Sinister sound of Tyrannosaurus Rex heard for first time in 66 million years

 Sarah Knapton, science editor 

9 DECEMBER 2017 • 7:00PM

The fearsome roar of Tyrannosaurus Rex as portrayed in film has left many a cinema-goer quaking in their seat.

But new research suggests the king of the dinosaurs made a far more sinister sound.

For a new BBC documentary, naturalist Chris Packham visited Julia Clarke, professor of Vertebrate Palaeontology at the University of Texas, to test out a the theory that dinosaurs actually sounded more like birds and reptiles, than today’s predatory mammals.

“The most chilling noises in the natural world today come from predators, the howl of the wolf, the roar of the tiger, but experts now doubt that T-Rex sounded anything like them,” said Packham.

Dinosaurs are the ancestors of birds and are closely related to alligators and crocodiles, so Prof Clarke used the sound of the Eurasian bittern, which makes an unearthly booming call, and the vocalisations of Chinese crocodiles to estimate the noise T-Rex would have made.

Read on   

A mother’s long distance call help their seal pups find them

Identifying their mother’s voice is crucial for helping Antarctic fur seal pups find their mothers in densely populated breeding colonies, when they return from foraging for food, new research has found.

Antarctic fur seals breed in dense colonies on shore, and during the 4-month lactation period, mothers alternate foraging trips at sea with suckling period ashore. Each time the mothers return to the colony, they and their pups initially use vocalizations to find each other among several hundred other seals, and then use their sense of smell to confirm.

The team from University of Paris-Sud carried out playback experiments on about 30 wild pups using synthetic signals and playbacks at different distances at the Kerguelen Archipelago in the southern Indian Ocean.

The authors found that the pups use both the sound's amplitude and frequency modulations to identify their mother's voice. Playbacks at different distances showed that frequency modulations propagated reliably up to 64 meters, whereas amplitude modulations were highly degraded for distances over 8 meters. The authors suggest these results indicate a two-step identification process: at long range, pups identified first the frequency modulation pattern of their mother's calls, and then other components of the vocal signature were identified at closer range. The individual vocal recognition system developed by Antarctic fur seals is likely adapted to face the importance of finding kin in a crowd.

You can read the full study HERE

Source ..

Scientists study 'talking' turtles in Brazilian Amazon

Date:

August 14, 2014

Source:

Wildlife Conservation Society

Summary:

Turtles are well known for their longevity and protective shells, but it turns out these reptiles use sound to stick together and care for young. Scientists working in the Brazilian Amazon have found that Giant South American river turtles actually use several different kinds of vocal communication to coordinate their social behaviors, including one used by female turtles to call to their newly hatched offspring in what is the first instance of recorded parental care in turtles.

read more ...

There's more than one way to silence a cricket: Co-evolution of crickets who lost their chirp

Date:

May 29, 2014

Source:

Cell Press

Summary:

For most of us, crickets are probably most recognizable by the distinctive chirping sounds males make with their wings to lure females. But some crickets living on the islands of Hawaii have effectively lost their instruments and don't make their music anymore. Now researchers report that crickets living on different islands quieted their wings in different ways at almost the same time.

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Darkness sharpens hearing in adult mice

Rapid brain-cell changes in animals kept in the dark give them better discrimination of sounds.

Could being visually impaired have had a role in the musical genius of Stevie Wonder and Ray Charles? A study provides some clues by showing that adult mice kept in the dark quickly develop sharper hearing and become better at distinguishing pitch and frequency. The improvements were correlated with adaptations in the brain — such as strengthening of connections between neurons — that normally happen only early in life.

Continued

Caught in the Act: Bats Use the Sound of Copulating Flies as a Cue for Foraging

ScienceDaily (July 20, 2012) — Mating activities are a dangerous business because the attention to other important events in the surroundings is often reduced. Therefore the duration of copulation itself is usually very short. About 100 years ago researchers argued that copulating animals are at a higher risk of being discovered and, consequently, being eaten by a predator. Yet, surprisingly, there are only few observations that support this hypothesis. These examples comprise studies in water-living insects, such as amphipods and water striders, and also in land insects, as investigated in a recent study in Australian plague locusts that are at a higher risk of being eaten as mating pairs compared to single animals.

Apart from decreased attention, a reduced flight response as well as an enhanced conspicuousness induces a higher risk for these winged lovers to be easy prey. Stefan Greif from the Max Planck Institute for Ornithology, and colleagues, have now provided experimental proof for this phenomenon. In a community of house flies and Natterer's bats in a cowshed near Marburg, Germany, they analysed videotapes of the movements of almost 9000 flies. The researchers found that the flies rarely fly at night and mostly sit or run on the ceiling. Finding the flies by echolocation is nearly impossible for the bats as the faint insect echo is completely masked by the strong background echo which makes them virtually "invisible."

Continued:  http://www.sciencedaily.com/releases/2012/07/120723134525.htm

Bird's rare solid wing-bone developed for wooing

Cornell researchers first reported in 2005 on the ability of these birds to rub specialized wing feathers together to produce a high hum. Now they report in the June 13 edition of the Royal Society journal Biology Letters that these are the first flying birds known to have solid wing-bones. This is what allows these birds to produce their courtship sounds.

In the male club-winged manakin, the ulna (analogous to a human bone in the forearm) is ridged, solid instead of hollow and 3.5 times the volume of other similar-sized birds' ulnae, including other manakin species. Special sound-producing feathers attached to the ulna resonate to make the courtship tones. The researchers also found similar but lesser adaptations to the humerus, which is the same as the bone between elbow and shoulder in humans.

The researchers believe the large, dense bones are adapted for courtship and come at a cost to efficient flight where lighter, hollow bones are ideal. The adaptations offer an extreme example of a species modifying a body part to attract a mate, but with a presumed cost to its fitness.

"The idea that there's this conflict between sexual selection and natural selection is not new," said Kim Bostwick, curator of the Cornell Museum of Vertebrates and lead author of the study. For example, a male peacock's large, showy feathers also inhibit flight but work well to attract females. But with the club-winged manakin, the adaptation "isn't just the feathers and what they look like. This is a functional change at the deepest levels. Ultimately, it's the female that's responsible for this odd bone inside the wing of the male," Bostwick added.

The researchers used microcomputer tomography (CT) scanners to noninvasively obtain complete density data of the inside of the bird bones, which could then be reconstructed into 3-D color images.

Read on and see video at:  http://phys.org/news/2012-06-bird-rare-solid-wing-bone-wooing.html