Posts Tagged ‘Rodents’

Mammalian Neurogenesis Breaks Into The Most Static Brain Region

June 9, 2008

Fifteen years ago, the discovery of adult neurogenesis (the production of new neurons) in the highly static, non-renewable mammalian brain was a breakthrough in neuroscience. Most emphasis was put on the possibility to figure out new strategies for brain repair against the threath of neurodegenerative diseases. Yet, unlike lower vetebrates, which are characterized by widespread postnatal neurogenesis, neurogenic sites in mammals are highly restricted within two very small regions. Hence, the fact that protracted neurogenesis in mammals is an exception rather than the rule slowes down hopes for generalized brain repair.

Work carried out in the recent past at the University of Turin, involving Federico Luzzati and Paolo Peretto at the Department of Animal Biology, and Giovanna Ponti and Luca Bonfanti at the Department of Veterinary Morphophysiology, revealed striking examples of structural plasticity and neurogenesis in the nervous system of rabbits. These Lagomorphs show remarkable differences under the profile of neurogenesis with respect to their close relatives Rodents (mice and rats).

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World’s strangest looking animals

June 3, 2008

“The Mickey Mouse of the desert” – mouse-like rodent with a long tail, long hind legs for jumping, and exceptionally large ears. The jerboa, found in the deserts of Mongolia and China, is listed as endangered on the IUCN Red List.

Click here for the full list and photos of the world’s strangest animals.

Ohio’s coyote comeback good news for gardeners

March 16, 2008

 I’m not really sure if I would consider this to be good news.  I LIKE rabbits and racoons and deer and geese (but then again, I have only one member of that menagerie at my house – racoons).  Besides, coyotes also attack and kill domestic pets.  I wonder if they would also attack and kill small children left to play by theirselves?  Readers, do you know?

Anyway, while I don’t want coyotes to disappear, I probably wouldn’t be too excited about having a bunch of them in my backyard, either.  How about you?

-Kitty Mowmow

Ohio’s coyote population is growing. That’s good news for many of you.

Coyotes prowling your yard will eat the rabbits and rodents that munched your garden. They will scare away trash-raiding raccoons and the deer eyeing your favorite bushes. They also eat the eggs of those messy Canada geese so many of you loathe.

“I call coyotes nature’s animal-control officers, because they control the populations of every kind of urban wildlife people complain about, and do it so neatly, quietly and efficiently that most of the time most folks have no idea that coyotes are among them,” said Merritt Clifton, editor of the international Animal People newspaper.

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What happens when a rat stops dreaming?

January 3, 2008

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 What happens when a rat stops dreaming? In 2004, researchers at the University of Wisconsin at Madison decided to find out. Their method was simple, if a bit devilish. Step 1: Strand a rat in a tub of water. In the center of this tiny sea, allot the creature its own little desert island in the form of an inverted flowerpot. The rat can swim around as much as it pleases, but come nightfall, if it wants any sleep, it has to clamber up and stretch itself across the flowerpot, its belly sagging over the drainage hole.

In this uncomfortable position, the rat is able to rest and eventually fall asleep. But as soon as the animal hits REM sleep, the muscular paralysis that accompanies this stage of vivid dreaming causes its body to slacken. The rat slips through the hole and gets dunked in the water. The surprised rat is then free to crawl back onto the pot, lick the drops off its paws, and go back to sleep—but it won’t get any REM sleep.

Step 2: After several mostly dreamless nights, the creature is subjected to a virtual decathlon of physical ordeals designed to test its survival behaviors. Every rat is born with a set of instinctive reactions to threatening situations. These behaviors don’t have to be learned; they’re natural defenses—useful responses accrued over millennia of rat society.

The dream-deprived rats flubbed each of the tasks. When plopped down in a wide-open field, they did not scurry to the safety of a more sheltered area; instead, they recklessly wandered around exposed areas. When shocked, they paused briefly and then went about their business, rather than freezing in their tracks the way normal rats do. When confronted with a foreign object in their burrow, they did not bury it; instead, they groomed themselves. Had the animals been out in the wild, they would have made easy prey.

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It’s Giant Rodent Day at Kitty Mowmow’s Animal Expo!

December 28, 2007

The most recent news out of Papua New Guinea is the discovery of a giant rat. Now, we don’t really like rats at the best of times, and a rat that’s five times larger than the normal variety sounded kind of scary. But actually this picture makes the Mallomys giant rat seem kinda cute. (see picture below)

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Are any of my readers familiar with the ROUS’s (Rodents of Unusual Size) from The Princess Bride Books and movies? These two critters bear a striking resemblance:

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Hopefully Mallomys doesn’t have an unquenchable thirst for human blood.

Check out this real rodent of unusual size,the capybara! The capybara is the world’s largest living rodent species.

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According to this Wikipedia article: Capybaras are social animals, usually found in groups, between 10 and 30 (though looser groups of up to 100 sometimes can be formed),controlled by a dominant male, who will have a prominent scent gland on his nose used for smearing his scent on the grasses in his territory. They communicate through a combination of scent and sound, being very vocal animals with purrs and alarm barks, whistles and clicks, squeals and grunts.

Capybaras are excellent swimmers and can survive completely underwater for up to five minutes, an ability they will use to evade predators. If necessary, a Capybara can sleep underwater, keeping its nose just at the waterline.

Capybaras eat their own feces in the morning in order to help digest the cellulose in the grass that forms their normal diet. During midday, as temperatures increase, Capybaras wallow in water to keep cool and then graze in late afternoons and early evenings. They sleep little, usually dozing off and on throughout the day and grazing into and through the night.

Millions of years ago, the largest rodent known to man roamed the earth, Phoberomys pattersoni.

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According to Wikipedia: Phoberomys pattersoni was a rodent that lived in the ancient Orinoco River delta approximately 8 million years ago. It was the second-largest of the roughly 7 species of its genus. Like many other rodents, Phoberomys was a herbivore with high-crowned premolars and molars.

An almost complete skeleton of P. pattersoni, discovered in Urumaco, Venezuela in 2000, has enabled researchers to reconstruct its size and probable lifestyle. It was 3 m(9.8 ft) long, with an additional 1.5 m (5 ft.) tail, and probably weighed around 700 kilograms, making it the largest rodent for which a good size and weight estimate is currently possible. Its congener Phoberomys insolita was a bit larger still, but it is not known from any reasonably complete remains and thus its size cannot be estimated more precisely.