December 17, 2007: Brave Mice

[Clodfobble]

Fear is all in your head! Or at least it is for mice. That's what the Japanese researchers at Tokyo University set out to prove when they created a new breed of genetically modified mice that are not afraid of cats. By turning off certain smell receptors in the brains of their mice, the scientists were able to show that their newly-ballsy mice are only instinctively afraid of the predators' smell, rather than learning from experience that cats will gobble them up.

Alternatively, I suggest that they could design genetically odorless cats. Seems more useful in the long run to me.

[barefoot serpent]

They've done the glow-in-the-dark cats so why not odorless?

[BigV]

I remember reading a story about this topic, and I think it was something about the smell of the cat's urine that triggered a fear reaction in the mice. As to the observation about the path to learning in the mice, how exactly would a mouse learn from experience that cats gobble them up. More to the point, how can the mouse communicate that learning to other mice?

[Kingswood]

Originally Posted by Clodfobble

[T]he scientists were able to show that their newly-ballsy mice are only instinctively afraid of the predators' smell, rather than learning from experience that cats will gobble them up.

Mice do not get a lot of opportunity to learn from experience as far as a cat is concerned.

Mouse makes a mistake around a cat, gulp, burp. Mouse makes a mistake around a cat, gulp, burp. Mouse makes a mistake around a cat, gulp, burp. Mouse makes a mistake around a cat, gulp, burp. Mouse makes a mistake around a cat, gulp, burp.

Yep, sure can't see many mice making a cat-related mistake and having the opportunity to learn from the experience (assuming wild mice and wild cats).

[jinx]

Originally Posted by Clodfobble

Fear is all in your head! Or at least it is for mice. That's what the Japanese researchers at Tokyo University set out to prove when they created a new breed of genetically modified mice that are not afraid of cats. By turning off certain smell receptors in the brains of their mice, the scientists were able to show that their newly-ballsy mice are only instinctively afraid of the predators' smell, rather than learning from experience that cats will gobble them up.

Mice and rats who are infected with toxoplasmosis (The "pregnant women shouldn't change the litter box" disease.) also have no fear of cats.

Behavioral changes

It has been found that the parasite has the ability to change the behavior of its host: infected rats and mice are less fearful of cats - in fact, some of the infected rats seek out cat-urine-marked areas. This effect is advantageous to the parasite, which will be able to sexually reproduce if its host is eaten by a cat.[12] The mechanism for this change is not completely understood, but there is evidence that toxoplasmosis infection raises dopamine levels in infected mice.


The findings of behavioral alteration in rats and mice have led some scientists to speculate that toxoplasma may have similar effects in humans, even in the latent phase that had previously been considered asymptomatic. Toxoplasma is one of a number of parasites that may alter their host's behaviour as a part of their life cycle. [13] The behaviors observed, if caused by the parasite, are likely due to infection and low-grade encephalitis, which is marked by the presence of cysts in the brain, which may produce or induce production of a neurotransmitter, possibly dopamine, [14] therefore acting similarly to dopamine reuptake inhibitor type antidepressants and stimulants.

"In populations where this parasite is very common, mass personality modification could result in cultural change. [Variations in the prevalence of Toxoplasma gondii] may explain a substantial proportion of human population differences we see in cultural aspects that relate to ego, money, material possessions, work and rules." — Kevin Lafferty [15]

Correlations have been found between latent Toxoplasma infections and various characteristics: [16]

• Decreased novelty-seeking behaviour [17]
• Slower reactions
• Lower rule-consciousness and jealousy (in men) [17]
• More warmth and conscientiousness (in women) [17]

The evidence for behavioral effects on humans, although intriguing, is relatively weak

[LJ]

that's it....i'm not changing the cat box any more. too risky.

[Razzmatazz13]

Nah, it's ok jim, I'm sure the baby will be fine.

[ZenGum]

I reckon this beast ain't afraid of no cat neither!



The 1.4kg Mallomys giant rat is one of two species of mammal found by Conservation International on an expedition to the Foja Mountains in the north of Papua province, Indonesia.
From the BBC.

[Shawnee123]

60 minutes went to the Foja mountains in a piece titled "Garden of Eden." It was nothing less than fascinating. Film clips may be found here.

[glatt]

Originally Posted by Kingswood

Mouse makes a mistake around a cat, gulp, burp. Mouse makes a mistake around a cat, gulp, burp. Mouse makes a mistake around a cat, gulp, burp. Mouse makes a mistake around a cat, gulp, burp. Mouse makes a mistake around a cat, gulp, burp.

Smart mouse who doesn't make mistake around cat lives to reproduce. Passes smart genes on.

Or,

Mouse with sensitive nose and hates the smell of cat piss stays away from cats and lives to reproduce. Passing sensitive nose genes on to kids.

[Clodfobble]

Or, mice generally don't live alone--mouse watches brother get eaten by a cat, grief stays fresh in his heart and reminds him to stay away from the cat.

[sweetwater]

it would be advantageous for cats to lose their odor, if one subscribes to M. Pollan's "Botany of Desire" premise, right? non-stinky pee cats are likely to become a more popular pet than a stinky pee cat. and they'd prove better de-mousers, too. toxo was just trying to help the process but got the wrong beasie.

[glatt]

Feed them asparagus?

[Edna]

If you want to see ideal coexistence between a cat and a mice check this pics.

It seems like love is in the air.

[xoxoxoBruce]

Welcome to the Cellar, Edna.