American science summit: How bears could help man get to Mars

 

Washington DC

An unprecedented investigation into the biology of hibernating bears has provided scientists with vital insight into "suspended animation", which might one day allow future space travellers to sleep for months at a time.

American black bears, Ursus americanus, are some of the largest animals to hibernate, yet scientists know little about how their bodies cope without eating, drinking or expelling waste for five to seven months during the winter period.

Some experts have even questioned whether bears experience true hibernation, because their body temperature falls only a few degrees below the normal 36C rather than plummeting to the near-freezing temperatures experienced by smaller mammals.

However, a study that monitored the daily physiological changes in five American black bears has found that they do indeed experience true hibernation, involving a dramatic 75 per cent decline in their basal metabolic rates – the amount of oxygen consumed by their body's tissues.

Scientists believe that the findings will give them valuable information about how to reduce metabolic activity in the human body, which could lead to new medical treatments, as well as preparing the body for space travel using suspended animation.

"When black bears emerge from hibernation, it has been shown that they have not suffered the losses in muscle and bone mass that would be expected to occur in humans," said Brian Barnes of the University of Alaska in Fairbanks.

"If we could discover the genetic and molecular basis for this protection, and for the mechanisms that underlie the reduction in metabolic demand, we could derive new therapies and medicines to prevent osteoporosis, disuse atrophy of muscle, or even place injured people in a type of suspended or reduced animation," Professor Barnes said.

One of the biggest surprises of the study, presented to the American Association for the Advancement of Science in Washington, was that black bears are able to slow down their metabolism without the dramatic fall in body temperature.

In smaller mammals a 50 per cent fall in metabolism, as measured by the amount of oxygen consumed per gram of body weight per hour, leads to a 10C fall in core body temperature. But in black bears, the study revealed that a 75 per cent decline in metabolic rate was accompanied by only a 5C or 6C fall in core temperature.

They also found that the heart of the black bear develops an unusual pattern of beating, slowing from 55 beats per minute to about 14 beats per minute, but varying according to whether the animals were breathing in at the time.

"Sinus arrhythmia is a variation in heartbeat frequency relative to breathing, and the bears show an extreme form of this. They have an almost normal heartbeat when they take a breath, but between breaths the bears' hearts beat very slowly," said Oivind Toien, of Alaska University.

"If our research could help by showing how to reduce metabolic rates and oxygen demands in human tissues, one could possibly save people. "

The experiment was carried out on black bears in Alaska that had strayed too close to human dwellings and were taken to a forest reserve where they were housed in wooden structures designed to simulate real dens.

After emerging from hibernation, it took 2-3 weeks for them to regain their normal metabolisms.

Start your day with The Independent, sign up for daily news emails
Life and Style
tech
Arts and Entertainment
Rocky road: Dwayne Johnson and Carla Gugino play an estranged husband and wife in 'San Andreas'
filmReview: In the face of all-round devastation, even Dwayne 'The Rock' Johnson appears a little puny
News
i100
Arts and Entertainment
Bright lights, big city: Melrose Avenue in Los Angeles by dusk
books
Sport
Harry Kane makes Paul Scholes' Premier League team of the season
footballPaul Scholes on the best players, managers and goals of the season - and the biggest disappointments
News
i100
News
ebookA unique anthology of reporting and analysis of a crucial period of history
Latest stories from i100
Have you tried new the Independent Digital Edition apps?
Independent Dating
and  

By clicking 'Search' you
are agreeing to our
Terms of Use.

iJobs Job Widget
iJobs General

Recruitment Genius: Web Developer - Junior / Middleweight

Negotiable: Recruitment Genius: One of the South East's fastest growing full s...

Guru Careers: Marketing Manager / Marketing Communications Manager

£35-40k (DOE) + Benefits: Guru Careers: We are seeking a Marketing Communicati...

Recruitment Genius: Commercial Engineer

£30000 - £32000 per annum: Recruitment Genius: Estimating, preparation of tech...

Recruitment Genius: IT Support Technician

£14000 - £17000 per annum: Recruitment Genius: You will work as part of a smal...

Day In a Page

Fifa corruption: The 161-page dossier that exposes the organisation's dark heart

The 161-page dossier that exposes Fifa's dark heart

How did a group of corrupt officials turn football’s governing body into what was, in essence, a criminal enterprise? Chris Green and David Connett reveal all
Mediterranean migrant crisis: 'If Europe thinks bombing boats will stop smuggling, it will not. We will defend ourselves,' says Tripoli PM

Exclusive interview with Tripoli PM Khalifa al-Ghweil

'If Europe thinks bombing boats will stop smuggling, it will not. We will defend ourselves'
Raymond Chandler's Los Angeles: How the author foretold the Californian water crisis

Raymond Chandler's Los Angeles

How the author foretold the Californian water crisis
Chinese artist who posted funny image of President Xi Jinping facing five years in prison as authorities crackdown on dissent in the arts

Art attack

Chinese artist who posted funny image of President Xi Jinping facing five years in prison
Marc Jacobs is putting Cher in the limelight as the face of his latest campaign

Cher is the new face of Marc Jacobs

Alexander Fury explains why designers are turning to august stars to front their lines
Parents of six-year-old who beat leukaemia plan to climb Ben Nevis for cancer charity

'I'm climbing Ben Nevis for my daughter'

Karen Attwood's young daughter Yasmin beat cancer. Now her family is about to take on a new challenge - scaling Ben Nevis to help other children
10 best wedding gift ideas

It's that time of year again... 10 best wedding gift ideas

Forget that fancy toaster, we've gone off-list to find memorable gifts that will last a lifetime
Paul Scholes column: With the Premier League over for another year, here are my end of season awards

Paul Scholes column

With the Premier League over for another year, here are my end of season awards
Heysel disaster 30th anniversary: Liverpool have seen too much tragedy to forget fateful day in Belgium

Liverpool have seen too much tragedy to forget Heysel

Thirty years ago, 39 fans waiting to watch a European Cup final died as a result of a fatal cocktail of circumstances. Ian Herbert looks at how a club dealt with this tragedy
Amir Khan vs Chris Algieri: Khan’s audition for Floyd Mayweather may turn into a no-win situation, says Frank Warren

Khan’s audition for Mayweather may turn into a no-win situation

The Bolton fighter could be damned if he dazzles and damned if he doesn’t against Algieri, the man last seen being decked six times by Pacquiao, says Frank Warren
Blundering Tony Blair quits as Middle East peace envoy – only Israel will miss him

Blundering Blair quits as Middle East peace envoy – only Israel will miss him

For Arabs – and for Britons who lost their loved ones in his shambolic war in Iraq – his appointment was an insult, says Robert Fisk
Fifa corruption arrests: All hail the Feds for riding to football's rescue

Fifa corruption arrests

All hail the Feds for riding to football's rescue, says Ian Herbert
Isis in Syria: The Kurdish enclave still resisting the tyranny of President Assad and militant fighters

The Kurdish enclave still resisting the tyranny of Assad and Isis

In Syrian Kurdish cantons along the Turkish border, the progressive aims of the 2011 uprising are being enacted despite the war. Patrick Cockburn returns to Amuda
How I survived Cambodia's Killing Fields: Acclaimed surgeon SreyRam Kuy celebrates her mother's determination to escape the US

How I survived Cambodia's Killing Fields

Acclaimed surgeon SreyRam Kuy celebrates her mother's determination to escape to the US
Stephen Mangan interview: From posh buffoon to pregnant dad, the actor has quite a range

How Stephen Mangan got his range

Posh buffoon, hapless writer, pregnant dad - Mangan is certainly a versatile actor