Showing posts with label Mice. Show all posts
Showing posts with label Mice. Show all posts

Clockwise


We are all creatures of habit, even when we try to be spontaneous. True spontaneity is very difficult to keep up and we revert back to our humdrum regular behavior. Along with this habitual behavior comes our dependence on the clock. Even when we neglect to set the alarm, hoping, perhaps, that we may sleep in, we wake up as usual a few minutes before it is due to go off. Our circadian rhythms seem to take all our essential activities into account.

Mealtimes are just one of those essential activities and we start getting restive as they approach. Our animal friends also find themselves in the same boat. Once they get used to a set of mealtimes, they start to get excited as their internal clock warns them to get ready. Luby et al decided to use their mice to check out how they felt about regular feeding and published their data in PLoS ONE (1).

To start with, they put groups of their mice on a restricted calorie diet so there would be no eating between meals to spoil their appetites. Several regular feeding regimens were tried at 12, 8 and 4 hour intervals and the mice quickly got used to that and stamped about impatiently waiting for service.

18 hour feeding intervals were not well received as food would not arrive at a regular time each day and the mice could not fit lunch conveniently into their circadian rhythm. They did make an effort, but gave that idea a resounding raspberry.

A much more popular option was being fed once a day at a regular time, but with the meal split up into 6 small helpings served at 30 minute intervals, allowing plenty of time for socializing as a well brought up mouse may wish to do.

The net result was to show that mice were distinctly clockwise and therefore, creatures of habit governed by circadian clocks just like us. So if you want to catch your mice, try feeding them at regular times each day and avoid putting that trap out at odd times when you happen to think about it – they are much less likely to cooperate.

  1. http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0037992


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Life In The Fast Lane


Many of us watch our diet and exercise regimen and still struggle to keep our weight constant, let alone reduce it. As stress in our lifestyle increases, we can direct less effort in that direction. In the face of expensive possible solutions ranging from surgery, fancy diet pills, and weight loss foods and drinks, it is encouraging to read the BBC report of a more fun solution (1).

 Mice not men are the subjects of the studies by During et al at Ohio State U. First they showed that if their mice had a socially stimulating lifestyle with lots of friends and colleagues and many little challenging things to do, they stimulated the production of the protein BDNF, (Brain-Derived-Neurotrophic Factor), that encourages more neurons to grow  from neural stem cells.

The new and exciting development is that they have demonstrated that BDNF starts the conversion process of the white fat plumping up our experimental subjects into brown, energy producing fat.

The big experiment was then embarked on. Mice who had been in a dull restricted environment and had become very plump couch potatoes were introduced to the social milieu with lots of environmental complexity to make life fun and challenging, that is, good stress not bad stress. They were given amazing mazes, wooden toys, little huts to do whatever mice do in the dark as well as running wheels and the like.

The result? In a month the mice had lost half of their surplus white fat and were now svelte little socialites. Even their body temperatures had risen due to all that fat burning. Life in the fast lane had done the trick.

The same should be true for us. A busy, fun social life with lots of fun physical challenges is something to be put on the agenda, or at least at the top of the list for next year’s resolutions.
  1. http://www.bbc.co.uk/news/science-environment-14813485

Retiring Mice


Flipping through the bio papers in the scientific literature, I seem to come across a very large number associated with aging – or its reversal and longevity. Of course we would all like to be long lived with the minimal amount of aging related lack of spryness. Many of the studies are associated in one way or another with our diet, and diet and exercise is what we are told to pay attention to when we visit the doctor if we can bring ourselves to do that.

Today’s post is about a helping retired mice grow older. The paper is by Matsumoto et al in the Public Library of Science (1). The retirees were all females who had spent the previous ten months raising litters. Male retirees couldn’t be considered for the study as they tend to be very, very, grumpy and fight all the time.

So, these old girls were allowed to enjoy their retirement for another eleven months with half of them fed on a probiotic diet. The good bacteria were from milk although the mice didn’t have access to live Greek yogurt, or any yogurt come to that. The good bacteria in the diet result in there being higher levels of polyamines in the colon.

The simplest polyamine is putrescine, so as you can imagine, these don’t smell too good, but they are important in body functions such as cell growth and the synthesis of our DNA and RNA. But they are also anti-inflammatory and this was at the root of the reason for the study. Is longevity increased if chronic low-grade inflammation is suppressed?

Those on the probiotic diet were longer lived and also ended up with better colons. So it’s just like your Mom told you about an apple a day, but now it’s take care of your colon and it’ll take care of you. I will be eating more live Greek yogurt and using lots more Soy sauce in my cooking and am looking forward to a long retirement (eventually).

  1. http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0023652

Put Your Thinking Cap On


Running around and doing what we like is what we associate with free will. What on earth were you thinking about when you did that is a question that we are sometimes faced with afterwards. Mostly, we don't have any idea. It all went with the moment.

Then as we sit like gods on Mount Olympus watching our lab mice or rats run about in our mazes trying to solve problems, we ask the same question: "what are they thinking?" We can make a start on this quest if we know which parts of their tiny minds are flashing electric pulses from neuron to neuron. The conventional solution is to stick electrodes into the brain and wire the beasties up to computers. However, running around and behaving normally must be hard to do with thick heavy cables hanging off your head.

A new solution is now available. A large multinational team have come up with mouse and rat-sized thinking caps (1). The electrodes are still obligatory, but the hats have multi-channel radio transmitters kitted out with re-chargeable batteries. So after a day or so of running around, the mouse or rat is simply plugged into the lab electricity supply for a while and they're all ready to go on the next set of experiments.

The hats are used to follow the brain activity of, to quote the authors, "freely behaving mice and rats." I'm not sure how freely behaving I would be if I was trying to solve problems with a big hat containing a radio transmitter and battery of the same relative size as their mice are wearing. I would be terribly self-conscious and feeling definitely geeky if not a tad exploited. Certainly, my compensation would have to be increased if I were to play ball.

  1. http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0022033

Singing Mice


With the speculation and rumors around the Oscars at their peak and, indeed, becoming a tad monotonous, we lessor mortals should have foreseen that the American Association for the Advancement of Science would have dedicated a symposium at its Annual Meeting to the subject of stuttering, with three lectures this morning.  The subtitle of the symposium was ‘Untangling the Mystery of Stuttering’ (1)and it is an interesting change from the past in that these newer multidisciplinary approaches are breaking new ground. The Guardian UK gives a detailed account of Dr. Drayna’s presentation (2).

Apparently, there are three genes with particular mutations involved. Mutations in these can result in a deficit of the correct products from the cell metabolism. To test this theory, a set of GM mice have been produced with these three genes inactive. Mr. Mouse bursts into song at the drop of the right pheromone. They sing for minutes and prefer to write their own music. The music is too high pitched for us being just into the ultrasonic but just fine for cats and dogs. If the theory is on target, they will have some very frustrated mice as I don’t expect that the females will come rushing if the singers of the love songs are having difficulty in getting the words out. Drayna’s objective is to design an anti-stutter pill.

The work of du Nil was on a different tack. Using imaging techniques, he has shown that several areas of the brain are involved through differences in activation. This would seem to suggest a fairly complex interaction is at the root cause of a stutter and a pill may be a long way off.

Going up in brain size from mice to rats, a recent neuronal protein study by Dr. Bossert (3) indicated that specific regions of the front part of the brain are involved in drug addiction. Some rat subjects were taught to self medicate with heroin until they were nicely addicted and then they were sent to a rehab unit to clean up. Apart from being a drug-free zone, the quarters became nice and bright and the rats cleaned up their act. However, when back with the sleazy environment, they fell off the wagon. They could get drug help them though by injections of drugs that inhibited the part of the brain wound up by their heroin addiction. I guess you can take the rat out of the street but not the street out of the rat.


1.      http://aaas.confex.com/aaas/2011/webprogram/Session2789.html

2.      http://www.guardian.co.uk/science/2011/feb/20/scientists-create-gm-mice-stuttering

3.      http://www.nature.com/neuro/journal/vaop/ncurrent/full/nn.2758.html