July 4, 2012 - A natural drug discovered in the soil of Easter Island could improve the memory of older men and women - and even treat Alzheimer's, researchers say.
In tests in mice, the drug halted the decline in brain function as they got older, and supplied hope that it could also treat depression.
The drug - rapamycin - is a bacterial by-product discovered in the shadows of the island's popular statues.
It is named after Rapa Nui, the Polynesian name for Easter Island, which sits isolated in the Pacific ocean - 2000 miles from anywhere.
Easter Island heads: It is named after Rapa Nui, the Polynesian name for Easter Island, which sits isolated in the Pacific ocean - 2000 miles from anyplace
It is already utilized in transplant patients to avoid organ rejection and now scientists in journal Neuroscience say it can increase understanding and assist treat cognitive decline.
It could even treat situations like Alzheimer's, they believe.
A team from the University of Texas added the drug to the diet of healthy mice and discovered it enhanced learning and memory in young mice and memory in elder rodents.
Professor Veronica Galvan said: ‘We made the young ones discover, and bear in mind what they learned, far better than what is standard.
‘Among the older mice, the ones fed with a diet plan like rapamycin really showed an improvement, negating the normal decline that you see in these functions with age.’
The team also identified three ‘happy, feel-good’ neurotransmitters - serotonin, dopamine and norepinephrine - had been higher in the mice treated with rapamycin.
This could help clarify the effects on memory, she said, and helped back up earlier research which showed Alzheimer's like syndromes had been lowered in mice treated with the drug.
‘This is super-intriguing and one thing we are going to pursue in the lab,’ she stated.
It also lowered anxiety and depressive-like behaviour in the mice, she said.
Her colleague Dr Jonathan Halloran utilized a series of elevated tunnels that led to a catwalk to examine the behaviour of the rodents.
Mice prefer tunnels to open spaces and had been watched on the catwalk.
Dr Halloran mentioned: ‘All of a sudden the mice are in open space.
‘It's pretty far from the floor for their size, sort of like if a particular person is hiking and suddenly the trail gets steep. It really is pretty far down and not so comfortable.’Mice with much less anxiety were a lot more curious to discover the catwalk, he stated.
He explained: ‘We observed that the mice fed with a diet containing rapamycin spent significantly a lot more time out in the open arms of the catwalk than the animals fed with a regular diet plan.’
Similarly, when mice had been handled by their tails they would struggle, but depressed mice would struggle less.
‘So we can measure how considerably and how typically they struggle as a measure of the motivation they have to get out of an uncomfortable circumstance,’ said Dr Galvan.
‘We discovered rapamycin acts like an antidepressant - it increases the time the mice are attempting to get out of the scenario. ‘They don't give up they struggle far more.