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September 20, 2009

Paralyzed Rats Able to run on a Treadmill and Genetically Altered Mice Appetite Reduced but Metabolism Stays Up

1. Paralyzed rats (with severed spinal cords) given electrical stimulation on the skin by the spinal cord separation and a drug to enhance response to the electricity and were able to run on a treadmill.


Balance is not restored so if this were to work on people, they would need a walking frame for balance.

Transformation of nonfunctional spinal circuits into functional states after the loss of brain input

Abstract: After complete spinal cord transections that removed all supraspinal inputs in adult rats, combinations of serotonergic agonists and epidural electrical stimulation were able to acutely transform spinal networks from nonfunctional to highly functional and adaptive states as early as 1 week after injury. Using kinematics, physiological and anatomical analyses, we found that these interventions could recruit specific populations of spinal circuits, refine their control via sensory input and functionally remodel these locomotor pathways when combined with training. The emergence of these new functional states enabled full weight-bearing treadmill locomotion in paralyzed rats that was almost indistinguishable from voluntary stepping. We propose that, in the absence of supraspinal input, spinal locomotion can emerge from a combination of central pattern-generating capability and the ability of these spinal circuits to use sensory afferent input to control stepping. These findings provide a strategy by which individuals with spinal cord injuries could regain substantial levels of motor control.












2. Genetically altered mice had their appetite reduced, making it easy to eat less, but their bodies continued to burn the amount of calories it burned when they were eating normally, allowing them to keep the weight off. This could lead to the perfect fat reduction treatment in humans.

Mice were genetically engineered to limit the action of a gene called Cpe.



Over the course of several days, experimental mice and controls and were given a 70 per cent reduction in food. The experimental mice did not eat the full amount presented to them yet their energy expenditure remained at a normal level. Plum claims it is the first time this dissociation between food intake and energy expenditure has been seen.

As well as eating less than control mice, they ended up 15 per cent lighter with 27 per cent less body fat. And because their energy expenditure did not reduce along with their calorie intake, the weight stayed off.

Cpe is involved in anxiety, memory and reproduction in humans. So even if a weight-loss drug could be created, he says, it might be difficult to avoid unpleasant side effects.


10 pages of supplemental information

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