Right-Handed Males, Left-Handed Females?

This is true for sugar gliders (Petaurus breviceps) and grey short-tailed opossums (Monodelphis domestica), say biologists from Saint Petersburg State University, Russia.

Their study, published in the open access journal BMC Evolutionary Biology, shows that handedness in marsupials is dependent on gender.

This preference of one hand over another has developed despite the absence of a corpus callosum, the part of the brain, which in placental mammals allows one half of the brain to communicate with the other.

Many animals show a distinct preference for using one hand (paw, hoof) over another. This is often related to posture – an animal is more likely to show manual laterality if it is upright, related to the difficulty of the task, more complex tasks show a handed preference, or even with age. As an example of all three: crawling human babies show less hand preference than toddlers.

Some species also show a distinct sex effect in handedness but among non-marsupial mammals this tendency is for left-handed males and right-handed females.

In contrast, the team from Russia shows that male quadruped marsupials, such as who walk on all fours, tend to be right-handed while the females are left-handed, especially as tasks became more difficult.

“Marsupials do not have a corpus callosum – which connects the two halves of the mammalian brain together. Reversed sex related handedness is an indication of how the marsupial brain has developed different ways of the two halves of the brain communicating in the absence of the corpus callosum,” explains senior author Dr Yegor Malashichev.

New Form of Animal Communication Discovered

Sniffing, a common behavior in dogs, cats and other animals, has been observed to also serve as a method for rats to communicate—a fundamental discovery that may help scientists identify brain regions critical for interpreting communications cues and what brain malfunctions may cause some complex social disorders.

Researchers have long observed how animals vigorously sniff when they interact, a habit usually passed off as simply smelling each other. But Daniel W. Wesson, PhD, of Case Western Reserve University School of Medicine, whose research is published in Current Biology, found that rats sniff each other to signal a social hierarchy and prevent aggressive behavior.

Wesson, who drew upon previous work showing that, similar to humans, rodents naturally form complex social hierarchies, used wireless methods to record and observe rats as they interacted. He found that, when two rats approach each other, one communicates dominance by sniffing more frequently, while the subordinate signals its role by sniffing less. Wesson found that if the subordinate didn’t do so, the dominant rat was more likely to become aggressive to the other.

Wesson theorized the dominant rat was displaying a “conflict avoidance signal,” similar to a large monkey walking into a room and banging its chest. In response, the subordinate animal might cower and look away, or in the case of the rats, decrease its sniffing.

“These novel and exciting findings show that how one animal sniffs another greatly matters within their social network,” said Wesson, an associate professor of neurosciences. “This sniffing behavior might reflect a common mechanism of communication behavior across many types of animals and in a variety of social contexts. It is highly likely that our pets use similar communication strategies in front of our eyes each day, but because we do not use this ourselves, it isn’t recognizable as ‘communication’.”

Wesson’s findings represent the first new form of communication behavior in rats since it was discovered in the 1970s that they communicate through vocal ultrasonic frequencies. The research provides a basis for understanding how neurological disorders might impact the brain’s ability to conduct normal, appropriate social behaviors. 

Wesson’s laboratory will use these findings to better understand how certain behaviors go awry. Ultimately, the hope is to learn whether this new form of communication can help explain how the brain controls complex social behaviors and how these neural centers might inappropriately deal with social cues.

Sheep Help Scientists Fight Huntington’s Disease

When University of Cambridge neurobiologist Jenny Morton began working with sheep five years ago, she anticipated docile, dull creatures. Instead she discovered that sheep are complex and curious. Morton, who studies neurodegenerative diseases such as Huntington’s, is helping evaluate sheep as new large animal models for human brain diseases.

Huntington’s is a fatal, hereditary illness that causes a cascade of cell death in the brain’s basal ganglia region. The idea to use sheep to study this disease arose in 1993 in New Zealand, a country where sheep outnumber humans seven to one. Researchers had already identified disorders shared by humans and sheep, but University of Auckland neuroscientist Richard Faull and geneticist Russell Snell had a more ambitious notion. They decided to develop a line of sheep carrying Huntington’s, which is brought on by repeats within the gene IT15, in the hopes of studying the condition’s progression and developing a treatment. They accomplished their goal in 2006 after extensive efforts.

Why sheep? For one, they have big brains—comparable to macaques, which are the only other large animals currently used to study this disease—with developed, cortical folding like our own. Also, sheep can be kept in large paddocks with their fellows and monitored remotely via data-logger backpacks, allowing scientists to study these creatures in a natural setting with fewer ethical concerns than studying caged primates. What is more, these long-lived, social animals are active and expressive, recognize faces, and have long memories. They also learn quickly and engage in experiments readily. This has allowed Morton to develop cognitive tests similar to those given to humans. The researchers can study the full progression of Huntington’s—which in humans is associated with gradual mental and motor decline—and compare the changes with the normal functioning of healthy individuals.

This spring Faull, Snell, Morton and their colleagues will begin monitoring two flocks of Huntington’s sheep in Australia. One flock will be inoculated with one of the most promising therapies yet devised—a virus that silences IT15’s mutations—and the other will serve as the control. Currently no cure exists for any human brain disease. The researchers believe these studies could be a milestone. “The tragedy of this disease is enormous. It’s a curse on the family,” Faull says. “Maybe we can lift that curse.”

How the animals lost their sensors

For free-living organisms, the ability to sense and respond to the outside environment is crucial for survival. Eukaryotes, such as animals and plants, often have highly complex network systems in place to monitor their surroundings and respond effectively, but bacteria have developed a remarkably simple system. It’s called the ‘Two Component System’ because it literally relies on just two components; a sensor and a responder. The sensor picks up the signal, communicates this to the responder, which then causes the effect.

The picture above shows this process happening. The ‘communication’ of the message from the sensor to the responder, as shown by the coloured arrows, is carried out by transferring phosphate molecules. The signal interacting with the sensor causes the sensor to autophosphorylate (phosphorylate itself) and then pass the phosphate molecule onto the responder to trigger the response. The letters “H” and “D” are the actual amino-acids being phosphorylated; Histadine and Aspartate.

Although Two-Component Systems (TCS) are found in all three superkingdoms of life (archaea, bacteria and eukaryotes) they are suspiciously absent from the animal kingdom. Plants have them, as do fungi and several protazoa, but they just aren’t present in animals. For this reason they’ve been looked into as potential antibiotic targets as knocking out the Two-Component Systems of most bacteria is fatal.

Why don’t animals use TCS? To answer this you have to start looking at the evolution of the system itself, because despite being nominally present in eukaryotes such as plants and fungi, TCS are used very differently. Bacteria use TCS for sensing a wide variety of signals; stress, metabolism, nutrient regulation, chemotaxis, pathogen-host interactions etc. In eukaryotes on the other hand they are used sparingly; for ethylene responses and photosensitivity in plants and osmoregulation in fungi and slime moulds.

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Call that a ball? Dogs learn to associate words with objects differently than humans do

Previous studies have shown that humans between the ages of two to three typically learn to associate words with the shapes of objects, rather than their size or texture. For example, toddlers who learn what a ‘ball’ is and are then presented other objects with similar shapes, sizes or textures will identify a similarly-shaped object as ‘ball’, rather than one of the same size or texture.

Earlier research with dogs has shown that they can learn to associate words with categories of objects (such as ‘toy’), but whether their learning process was the same as that of humans was unknown.

In this new study, the scientists presented Gable, a five year old Border Collie, with similar choices to see if this ‘shape bias’ exists in dogs. They found that after a brief training period, Gable learned to associate the name of an object with its size, identifying other objects of similar size by the same name. After a longer period of exposure to both a name and an object, the dog learned to associate a word to other objects of similar textures, but not to objects of similar shape.

According to the authors, these results suggest that dogs (or at least Gable) process and associate words with objects in qualitatively different ways than humans do. They add that this may be due to differences in how evolutionary history has shaped human and dog senses of perceiving shape, texture or size.

Nose cell transplant enables paralysed dogs to walk

Scientists have reversed paralysis in dogs after injecting them with cells grown from the lining of their nose.

The pets had all suffered spinal injuries which prevented them from using their back legs. The Cambridge University team is cautiously optimistic the technique could eventually have a role in the treatment of human patients. The study is the first to test the transplant in “real-life” injuries rather than laboratory animals.

In the study, funded by the Medical Research Council and published in the neurology journal Brain, the dogs had olfactory ensheathing cells from the lining of their nose removed. These were grown and expanded for several weeks in the laboratory.

Cat brain surgery: the story of an operation – in pictures

Harry, a 12-year-old maine coon, has a tumour on his pituitary gland, causing uncontrolled diabetes. In an attempt to save his life, his owners have opted for cutting-edge brain surgery at the Royal Veterinary College’s Queen Mother hospital for animals.

Cockatoo ‘can make its own tools’

A cockatoo from a species not known to use tools in the wild has been observed spontaneously making and using tools for reaching food and other objects.

A Goffin’s cockatoo called ‘Figaro’, that has been reared in captivity and lives near Vienna, used his powerful beak to cut long splinters out of wooden beams in its aviary, or twigs out of a branch, to reach and rake in objects out of its reach.

Researchers from the Universities of Oxford and Vienna filmed Figaro making and using these tools. How the bird discovered how to make and use tools is unclear but shows how much we still don’t understand about the evolution of innovative behaviour and intelligence.

A report of the research is published this week in Current Biology.

An elephant that speaks Korean

An Asian elephant named Koshik can imitate human speech, speaking words in Korean that can be readily understood by those who know the language. The elephant accomplishes this in a most unusual way: he vocalizes with his trunk in his mouth.

The elephant’s vocabulary consists of exactly five words, researchers report on November 1 in Current Biology, a Cell Press publication. Those include “annyong” (“hello”), “anja” (“sit down”), “aniya” (“no”), “nuo” (“lie down”), and “choah” (“good”). Ultimately, Koshik’s language skills may provide important insights into the biology and evolution of complex vocal learning, an ability that is critical for human speech and music, the researchers say.

"Human speech basically has two important aspects, pitch and timbre," says Angela Stoeger of the University of Vienna. "Intriguingly, the elephant Koshik is capable of matching both pitch and timbre patterns: he accurately imitates human formants as well as the voice pitch of his trainers. This is remarkable considering the huge size, the long vocal tract, and other anatomical differences between an elephant and a human."

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Animals learn to fine-tune their sniffs

Animals use their noses to focus their sense of smell, much the same way that humans focus their eyes, new research at the University of Chicago shows.

A research team studying rats found that animals adjust their sense of smell through sniffing techniques that bring scents to receptors in different parts of the nose. The sniffing patterns changed according to what kind of substance the rats were attempting to detect.

The sense of smell is particularly important for many animals, as they need it to detect predators and to search out food. “Dogs, for instance, are quite dependent on their sense of smell,” said study author Leslie Kay, associate professor of psychology and director of the Institute for Mind & Biology at the University of Chicago. “But there are many chemicals in the smells they detect, so detecting the one that might be from a predator or an explosive, for instance, is a complex process.”

Kay was joined in writing the paper by Daniel Rojas-Líbano, a postdoctoral scholar at the University of Chile in Santiago, who received his PhD from UChicago in 2011. Rojas-Líbano, who did the work as a doctoral scholar, was the first author on the publication. Their results are published in an article, “Interplay Between Sniffing and Odorant Properties in the Rat,” in the current issue of the Journal of Neuroscience.