No Cheese- I'm A Mouse

Article:

Mice, it seems, get cheesed off with cheese and would much prefer chocolate.

According to scientists, mice don't like cheese after all and would rather have food with high sugar content.

Mice prefer high sugar food

The subject has been exercising researchers from Manchester Metropolitan University and the Stilton Cheese Makers Association.

As part of a wider study into animals and food, they found that a mouse's diet is primarily made up of grains and fruit.

It found that they would reject something as strong in smell and rich in taste as cheese.

Dr David Holmes, an animal behaviourist from the university, said: "Clearly the supposition of mice liking cheese is a popular premise.

"Mice have evolved almost entirely without cheese or anything resembling it.

"Mice respond to the smell, texture and taste of food and cheese is something that would not be available to them in their natural environment and therefore not something that they would respond to."

Nigel White of the Stilton Cheese Makers Association said: "Blue Stilton cheese has a very distinctive aroma and has a huge fan base across the world but mice are clearly not among that."

Or even cheddar, it seems.

Rodents 'are smart enough'

Interesting Read

Rodents 'are smart enough'
26/03/2008 14:22 - (SA)

(From News24.com)

-Thanks Dru for finding this article.

Tokyo - Rodents can be trained to use tools and understand their functions, a Japanese study said on Wednesday, challenging a view that only primates and some birds are smart enough.

Six adult "degus" rodents, a kind of small rat, were trained at a laboratory at the Japanese government-funded RIKEN research institute and all of them were able to use a tiny T-shaped rake to retrieve food, it said.

In the final stage of the 60-day experiment, they were pulling the tool towards themselves to hold onto it and then moving it to obtain food, the study showed.

"A conventional view holds that the use of tools is a high-level ability, but animals in the class of rodents can do it if they are trained accordingly," said Kazuo Okanoya, who heads the study team, told AFP.

The findings suggested that a wide range of animals could use tools, although it may be doubtful for fish, he said.

It is the first study in the world to demonstrate that rodents can be trained to manipulate tools in a systematic way and understand their functions, according to the team.

The study, published on the online edition of the US science journal PLos ONE on Wednesday with motion pictures, showed that trained rodents picked at random all understood the tool.

The study said that "socio-ecological" factors may be the most important, rather than innate physical characteristics, in whether animals can use tools.

In one test they were given two tools - a familiar functional rake and a non-functional tool that lacked a blade or had a raised blade. They chose the functional one without hesitation in most cases.

They chose the correct tool without being tricked by its colour or size, the study said.

As it is easier to study rodents than macaque monkeys - the conventional laboratory animal for such research - the team hopes to conduct more research into what is happening in the brain at a molecular level when animals use tools.

The degus, whose scientific name is Octodon degus, is originally from Chile.

Introduction to Rodentia.

Good article explaining Rodentia..

Introduction to the Rodentia

Lodgepole Chipmunk. Photo by Dr. Lloyd Glenn Ingles © 1999 California Academy of Sciences.

The single largest group of mammals is the Rodentia. Most non-flying mammals are rodents: there are about 1,500 living rodent species (out of about 4,000 living mammals overall). Most people are familiar with mice, rats, hamsters, and guinea pigs, which are commonly kept as pets. The Rodentia also includes beavers, muskrats, porcupines, woodchucks, chipmunks, squirrels, prairie dogs, marmots, chinchillas, voles, lemmings, and many others. (Incidentally, the Rodentia does not include rabbits; rabbits differ from rodents in having an extra pair of incisors and in other skeletal features. Rabbits, hares, and a few other species make up the Lagomorpha. Shrews, moles and hedgehogs are also not rodents; they are classified in the Insectivora.)

Rodents are found native on all continents except Antarctica. One particular family of rodents, the Muridae, contains over 1100 species: over a quarter of all mammal species are rats, mice, voles, muskrats, lemmings, hamsters, gerbils, and other members of the Muridae. However, rodents show perhaps their greatest diversity of form in South America, which was an isolated continent for much of the Cenozoic. A few of these distinctive South American rodents include mountain viscachas, rabbit-like forms that inhabit dry mountainous regions; Patagonian cavies, very rabbit-like, fast-running forms with elongated ears and short tails; the coypu or nutria, a large marsh-dwelling rodent that has been introduced into North America and is hunted for its fur; and various burrowing forms such as pacas and tuco-tucos. Other South American rodents include guinea pigs, chinchillas, and New World porcupines (one species of which has dispersed into North America). The capybara (shown

at left), yet another South American species, is the largest living rodent. About the size of a pig, and reaching a maximum weight of 50 kg (110 pounds), the capybara is truly a rodent of unusual size. Capybaras live along rivers in the llanos (plains) of South America, and are often hunted or even ranched for their meat.

Despite their great species diversity, all rodents share common features. Rodents have a single pair of incisors in each jaw, and the incisors grow continually throughout life. The incisors have thick enamel layers on the front but not on the back; this causes them to retain their chisel shape as they are worn down. Behind the incisors is a large gap in the tooth rows, or diastema; there are no canines, and typically only a few molars at the rear of the jaws. Rodents gnaw with their incisors by pushing the lower jaw forward, and chew with the molars by pulling the lower jaw backwards. In conjunction with these chewing patterns, rodents have large and complex jaw musculature, with modifications to the skull and jaws to accommodate it. Like some other mammal taxa, but unlike rabbits and other lagomorphs, male rodents have a baculum (penis bone). Most rodents are herbivorous, but some are omnivorous, and others prey on insects. Rodents show a wide range of lifestyles, ranging from burrowing forms such as gophers and mole rats to tree-dwelling squirrels and

gliding "flying" squirrels, from aquatic capybaras and muskrats to desert specialists such as kangaroo rats and jerboas, and from solitary organisms such as porcupines to highly social organisms living in extensive colonies, such as prairie dogs (left) and naked mole rats.

Rodents cost billions of dollars in lost crops each year, and some are carriers of human diseases such as bubonic plague, typhus, and Hanta fever. However, various rodent species are economically important as sources of food or fur in many parts of the world, and others are used extensively in biomedical research.

Many early mammal taxa were superficially rodent-like, such as the extinct multituberculates. However, true rodents first appear in the fossil record towards the end of the Paleocene epoch. Their ancestry is probably to be found among a group of small fossil mammals known as anagalids, which may also have given rise to the Lagomorpha. The living rodent with the most archaic characters, most like the common ancestor of the Rodentia, is the sewellel or mountain beaver (which is not a true beaver at all) of the northwestern United States. During the Oligocene, the South American rodents began their great evolutionary radiation. By the Miocene, very modern-looking squirrels had evolved, as had the murids. Murids began their spectacular radiation in the Pliocene.

Noteworthy Pleistocene rodents include the extinct giant beaver, Castoroides, which was about the size of a bear. More prosaic rodent fossils from this time period, notably the teeth of voles and mice, have become important in reconstructing global climate patterns as well as in fine-scale studies of evolution.

Mouse Intelligence Measured

Mouse intelligence measured

Rodent 'g' might reveal genes for intellect.

HELEN PEARSON

Some mice are cleverer than others, say US neuroscientists. Their rodent equivalent of an IQ test might fuel the controversial pursuit for genes linked to human intelligence.

Scientists have long used a factor called general intelligence or 'g' to rate people's brainpower. The measure spans verbal, logical and mathematical tasks - so a person with a big 'g' tends to score highly in all intelligence quotient (IQ) tests, and do well in school and work.

Mice have a version of 'g', according to a team led by Louis Matzel of Rutgers University in Piscataway, New Jersey1. Animals that come top in one learning test often score better on others, they found: a maze champion might be a sniffing sensation too. "Once in a while you come across one that's absolutely stunning," says Matzel.

This might sound obvious - but because the tests are so laborious, few people have examined whether there are general differences between individual animals. Many studies average and compare the scores of groups of mice using one or two learning tasks.

Matzel's results imply that some mice have a general learning ability rather than, say, just being good at navigating or discriminating. This factor seems to underpin around 40% of the difference in task performance between individual mice, Matzel's team found.

Human 'g' also accounts for about 40% of variation in intelligence tests. "It's a terrifically important paper," says Robert Plomin, who studies intelligence at King's College, London. "It's by far the most stringent test of the hypothesis that you can find 'g' in mice."

Sceptics point out that Matzel's general learning factor may actually be a measure of a mouse's curiosity, motivation or athletic ability. "You might be testing what it's easy to test," warns psychologist Howard Gardner of Harvard University in Cambridge, Massachusetts.

G for genes

If the idea holds up, the mouse version of 'g' could help researchers to hunt for genes that underlie mouse learning power and, perhaps, human intelligence. Many studies have shown that 'g' is partly inherited, but it is difficult to track down relevant genes in people.

Matzel is already comparing the brain genes that are active in mice with high and low 'g' values. These might help re-wire nerve cells or boost signal firing.

Many experts are wary of this line of research, however. It raises the prospect that people might be labelled as clever or stupid on the basis of their genetic code, or that parents could screen embryos for intelligence genes.

Geneticists counter that such studies might instead reveal ways in which we can boost intelligence using, for example, nutrition or education. "They are difficult issues - but they're not as worrisome as we think," Plomin says.

Others argue that 'g' is a poor measure of human intelligence anyway. IQ tests, they say, are too crude to pick up individual talents. Gardner, for example, proposes that there are several distinct types of intelligence, such as logical, musical and interpersonal.

References
Matzel, L. M. et al. Individual differences in the expression of a 'general' learning ability in mice. Journal of Neuroscience, 23, 6423 - 6433, (2003). |Article|