Alzheimer's Protein Relieves MS Paralysis

An Alzheimer's protein relieves paralysis in MS, the mechanism behind sex discrepancy in life expectancy, cuckoos up to new tricks and why robots can benefit from a tail.
05 August 2012

Interview with 

Lawrence Steinman, Stanford University; Damian Dowling, Monash University; Rose Thorogood, University of Cambridge; Aaron Johnson, University of Pennsylvania

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Alzheimer's protein relieves MS paralysis

A protein found in the brain of Alzheimer's sufferers has been shown to relieve paralysis in mice with the autoimmune disease multiple sclerosis, or MS.

MS is caused by the immune system attacking the protective myelin sheath around nerve fibres in the central nervous system. One symptom is inflammation of the brain, which can result in paralysis.

Lawrence Steinman of Stanford University reports in Science Translational Medicine. "We found in the multiple sclerosis brain a molecule called beta amyloid. This molecule has a famous and villainous role in Alzheimer's disease where most scientists think it's the culprit at the root of the Alzheimer's dementia.

So we attempted to find out what this molecule might be doing by going backward and seeing, "Okay, it's in the MS brain. What it might to do in a mouse model of multiple sclerosis? To our great surprise, the molecule provided great benefit. Animals that were paralysed became better and the inflammation melted away in their brain." 

Why women live longer than men

Females outlive males not only in humans, but in many other species as well. According to research in the American Naturalist, this discrepancy could arise from the mechanism of inheritance of mitochondrial DNA.

Damian Dowling and his research team at Monash University have identified mutations in fruitfly mitochondrial DNA that are harmful to males but not females. "What we did was uncover numerous mutations within the genes of mitochondria that cause males to age faster and live shorter lives than females.

The existence of these mutations can be entirely attributed to a quirk in the way that mitochondrial genes are passed down from parents to children. While children receive copies of most of their genes from both their mothers and their fathers. They only receive mitochondrial genes from their mothers.

"The implication is profound. It means that evolution's quality control process only screens the quality of mitochondrial genes when they're inside mothers. So, if a mitochondrial mutation occurs that harms fathers, but has no effect on mothers, this mutation will slip through the gates of natural selection unnoticed."

A new disguise for cuckoos

Cuckoos famously parasitise other bird species by laying eggs in their nests and allowing the host species to raise them. Not only that, but cuckoo chicks have evolved to push out the host's own eggs in order to gain their foster parents' full attention.

Cuckoos also mimic the appearance of predatory grey sparrowhawks, intimidating the hosts out of attacking the cuckoo.

However, one host species, the reed warbler, can learn to recognise disguised cuckoos for what they really are, and will mob them on sight.

Research published in Science by Rose Thorogood of the University of Cambridge shows that the cuckoos are now evolving a counter-attack. A new disguise of a red-brown plumage helps part of the cuckoo population avoid reed warbler mobbings.

"So we know that cuckoos are in a race with their hosts. We know from previous work that reed warblers have learned to defend themselves against cuckoos by watching their neighbours to tell when a grey cuckoo is a grey cuckoo and not the dangerous sparrow hawk. But we also know that cuckoos come in different colours, so we wanted to know if this was yet another cuckoo trick to beat these host defences. So, the most exciting thing of what we found is that the reed warblers actually only learn about the cuckoo morph that they see their neighbours mob. And why this is exciting is it means that they're sharing information amongst each other to try and beat their enemies, but actually, in the process of sharing this specific information, it's in turn selecting for this new cuckoo disguise."

Rex the robot gets a tail

And finally, Aaron Johnson at the University of Pennsylvania has been exploiting a novel way to make robots better at travelling over rough terrain: by adding a tail.

Research at the University of California, Berkeley has helped understand how animals use their tails for enhanced balance and agility.

Johnson has applied these findings to create a tail for a Rex, a six-legged robot who was perfectly capable on flat ground, but needed a little extra help on rougher ground...

"This has allowed Rex to be able to right itself when it's falling. Two examples - one is if you're falling nose down, you're going to hit your face on the ground and maybe break a leg, but instead it kicks the tail and is able to land on all six legs safely. And then the other case maybe starting out level because you're running off of a cliff, but as you run over the edge, you're going to start to pitch downwards. And so, it's able to detect that, kick its tail up and still land on its feet."

And complete with its new tail, Rex is now capable of safely falling nose-first from heights of 2.7 times its own body length.

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