Our New ARC Grant on Motor Performance and Ageing

If you thought turning 30 was bad, you're not going to like this. 

We lose more than 0.5% of our muscle mass each year after 30, which decreases our ability to run, jump, swim and perform virtually any motor task. Age-related muscle loss (known as sarcopenia) increases our risk of dying due to injury and even illness, as the proteins in our muscles are a major source of fuel for our immune systems.

Elderly sea gypsy weaves nets in Phuket, Thailand

Elderly sea gypsy weaves nets in Phuket, Thailand

Bike riding in Sri Lanka         Photo credit: Getty Images

Bike riding in Sri Lanka        Photo credit: Getty Images

Luckily, there's a simple solution to the problem: getting off the couch.

Exercise improves the efficiency of muscle metabolism and makes muscles more protein-dense, which helps slow ageing. We live longer, healthier lives. 

For humans, motor ageing affects the quality and length of life. But what about animals? In nature, motor function literally means life or death, as individuals have to escape predators and catch prey to survive. They also have to find mates to reproduce. They have to run over varied terrain, in the night or day, driving rain or blazing sun, with varied body sizes and shapes. Males may have dangling testicles, females may have dangling babies. And they have to do all this while avoiding catastrophic injury. 

Last week, our research team - A/Prof Robbie Wilson, Dr Diana Fisher, Dr Hamish Campbell, Dr Celine Frere and me - got a major grant from the Australian Research Council to study a critical aspect of animal performance: how an animal's habitat affects its motor development and ageing

Well-endowed male antechinus

Well-endowed male antechinus

Male antechinus

Male antechinus

What does habitat have to do with anything? We believe that within a species, individuals living in more-complex (i.e. rocky or diverse or steep) environments will have better motor function and slower motor ageing than those living in simpler (flat or unvaried) environments. This will help them live longer and produce more offspring.

Over the next 3 years, we'll be testing these ideas on small mammals - including quolls and antechinus - both in the wild and in captivity. At our field sites, we'll use GPS trackers to understand how animals use complex versus simple habitats, and how this affects their motor performance, ageing and mating. At our research facility, we'll raise animals in complex versus simple habitats to measure differences in performance, muscle physiology and mating success between environments and over lifetimes. 

Our study will show how habitat use affects motor performance and ageing in wild animals, which is key to their conservation. But more than that, we hope to shed light on a new way of thinking about motor rehabilitation. Over 50% of elderly people will experience debilitating muscle loss in their lifetimes, yet little is known about how the complexity  of movement affects muscle quality.

So this is some of what we'll be doing these next few years! If you're interested in collaborating, volunteering or learning more, please get in touch - we'd love to hear from you. (amandacniehaus@gmail.com or a.niehaus@uq.edu.au)

*This post was originally published here .

Source: https://wilsonperformancelab.squarespace.c...

What Determines Gecko Fighting Performance | An Honours Project by Rebecca Wheatley

This is Rebecca. She just submitted her Honours thesis, and is probably chilling with a vodka lemonade on a beach somewhere. Or else she's wishing she was.

A couple months ago, I asked Bec to describe her thesis - and to show me the experiments she had running. Here's what she said:

My research is using Asian house geckos as a model to answer questions about how morphology, performance, metabolic rate and personality interact to affect fighting ability in animals.

Rebecca's work is exciting because few studies have evaluated how morphology (or body size | shape), physiology, and personality work together to determine animal performance.

And can animals really have personalities? Of course, but not like you and I do. In the non-human world, personality can refer to repeatable differences in behaviour among individuals. For example, some individuals consistently tend to be shy, and others tend to be bold. Boldness | shyness is important for animals, as it can determine the likelihood of obtaining food or mates, or getting captured by predators.

When I caught up with Rebecca, she was measuring geckos' metabolism in purpose-designed jars, which were hooked up to specialised equipment that measures oxygen consumption. Oxygen consumption is one way that scientists assess metabolic rate in animals in the lab.

Collecting data on gecko metabolism

Rebecca was also video recording interactions between randomised pairs of geckos. Asian house geckos are aggressive little lizards, and will sort out dominance via displays of their open mouths, biting, and | or chasing. In her thesis, Rebecca looked at which animals were likely to be dominant, and whether that depended on their metabolism, morphology, and | or personality. 

collecting data on gecko fighting

And what did she find? The oversimplified version is that bite force, body mass, and running speed were most important in determining gecko dominance. Big, fast, hard-biting geckos were likely to be winners. The surprising thing was that metabolism and boldness didn't seem related to fighting performance.

There's a lot more to Rebecca's research: she used all the information she collected on morphology | physiology | behaviour to test important ecological theories about how individuals should interact (known as game theories). But we'll talk more about that another time - we don't want to give away everything just yet.

Thank you Rebecca, for taking the time to share your honours work with us, and for being such a wonderful labmate!

written and photographed by Amanda Niehaus, PhD