Ability of the brain to protect Itself from damage revealed
25 February 2013 | 3564 Views
TEHRAN - The origin of an innate ability the brain has to protect itself from damage that occurs in stroke has been explained for the first time.
The Oxford University researchers hope that harnessing this inbuilt biological mechanism, identified in rats, could help in treating stroke and preventing other neurodegenerative diseases in the future.
'We have shown for the first time that the brain has mechanisms that it can use to protect itself and keep brain cells alive,' says Professor Alastair Buchan, Head of the Medical Sciences Division and Dean of the Medical School at Oxford University, who led the work.
The researchers report their findings in the journal Nature Medicine and were funded by the UK Medical Research Council and National Institute for Health Research.
Stroke is the third most common cause of death in the UK. Every year around 150,000 people in the UK have a stroke.
It occurs when the blood supply to part of the brain is cut off. When this happens, brain cells are deprived of the oxygen and nutrients they need to function properly, and they begin to die.
'Time is brain, and the clock has started immediately after the onset of a stroke. Cells will start to die somewhere from minutes to at most 1 or 2 hours after the stroke,' says Professor Buchan.
This explains why treatment for stroke is so dependent on speed. The faster someone can reach hospital, be scanned and have drugs administered to dissolve any blood clot and get the blood flow re-started, the less damage to brain cells there will be.
It has also motivated a so-far unsuccessful search for 'neuroprotectants': drugs that can buy time and help the brain cells, or neurons, cope with damage and recover afterwards.
The Oxford University research group have now identified the first example of the brain having its own built-in form of neuroprotection, so-called 'endogenous neuroprotection'.
They did this by going back to an observation first made over 85 years ago. It has been known since 1926 that neurons in one area of the hippocampus, the part of the brain that controls memory, are able to survive being starved of oxygen, while others in a different area of the hippocampus die. But what protected that one set of cells from damage had remained a puzzle until now.
'Previous studies have focused on understanding how cells die after being depleted of oxygen and glucose. We considered a more direct approach by investigating the endogenous mechanisms that have evolved to make these cells in the hippocampus resistant,' explains first author Dr Michalis Papadakis, Scientific Director of the Laboratory of Cerebral Ischaemia at Oxford University.
Working in rats, the researchers found that production of a specific protein called hamartin allowed the cells to survive being starved of oxygen and glucose, as would happen after a stroke.
They showed that the neurons die in the other part of the hippocampus because of a lack of the hamartin response.
The team was then able to show that stimulating production of hamartin offered greater protection for the neurons.
Professor Buchan says: 'This is causally related to cell survival. If we block hamartin, the neurons die when blood flow is stopped. If we put hamartin back, the cells survive once more.'
Finally, the researchers were able to identify the biological pathway through which hamartin acts to enable the nerve cells to cope with damage when starved of energy and oxygen.
The group points out that knowing the natural biological mechanism that leads to neuroprotection opens up the possibility of developing drugs that mimic hamartin's effect.
Professor Buchan says: 'There is a great deal of work ahead if this is to be translated into the clinic, but we now have a neuroprotective strategy for the first time. Our next steps will be to see if we can find small molecule drug candidates that mimic what hamartin does and keep brain cells alive.
'While we are focusing on stroke, neuroprotective drugs may also be of interest in other conditions that see early death of brain cells including Alzheimer's and motor neuron disease,' he suggests.
Most Read Stories
- Strive Masiyiwa explains why he writes on Facebook | 7529 views
- WhatsApp activates calling feature | 7125 views
- Send money to friends in Facebook Messenger | 5865 views
- Whatsapp calling craze hits Zimbabwe | 4654 views
- Land Rover Debuts 2016 Range Rover Sport With New 280Kw Hst Version | 4130 views
- 6,000,000th Land Rover lights up Solihull | 3245 views
Staff reporter | 27 April 2015 | 633 Views
Patrick Guramatunhu | 27 April 2015 | 911 Views
Dr Clifford Chitupa Mashiri, | 27 April 2015 | 1554 Views
Levie Tsongo, Cape Town | 27 April 2015 | 2330 Views
Stephen Jakes | 27 April 2015 | 1845 Views
Stephen Jakes | 27 April 2015 | 5042 Views
Temba Munsaka | 27 April 2015 | 739 Views
Stephen Jackson | 27 April 2015 | 640 Views
Ndou Paul | 27 April 2015 | 4439 Views
Edison Investment Research | 27 April 2015 | 1223 Views
Peacemaker Zano | 27 April 2015 | 2131 Views
Staff Reporter | 27 April 2015 | 2843 Views
Stephen Jackson | 27 April 2015 | 1677 Views
Staff reporter | 27 April 2015 | 1956 Views
Staff reporters | 27 April 2015 | 1993 Views
Staff Reporter | 27 April 2015 | 958 Views
Concerned Citizen | 27 April 2015 | 2300 Views
Staff reporter | 27 April 2015 | 1635 Views
Thobekile Zhou | 27 April 2015 | 1626 Views
Marvelous Moyo | 27 April 2015 | 1181 Views
Lloyd Gumbo | 27 April 2015 | 2217 Views
Loveness Bepete | 27 April 2015 | 3703 Views
Walter Mswazie | 27 April 2015 | 2786 Views
Mashudu Netsianda | 27 April 2015 | 3143 Views
Staff reporter | 27 April 2015 | 1985 Views
Staff reporter | 27 April 2015 | 5760 Views
Staff reporter | 27 April 2015 | 1469 Views
Staff reporter | 27 April 2015 | 2309 Views
Staff Reporter | 27 April 2015 | 1332 Views
Staff Reporter | 27 April 2015 | 1063 Views
Tawanda Marwizi | 27 April 2015 | 2746 Views
Bongani Ndlovu | 27 April 2015 | 2641 Views
Staff Reporter | 27 April 2015 | 1046 Views
Staff reporter | 26 April 2015 | 3360 Views
Tafadzwa Zimoyo | 23 April 2015 | 3349 Views
Staff reporter | 23 April 2015 | 2504 Views
AFP | 22 April 2015 | 4651 Views
Staff reporter | 21 April 2015 | 6766 Views