Scientists have found a mechanism that kicks in when the body is cooled and prevents the loss of brain cells, and say their find could one day lead to treatments for brain-wasting diseases such as Alzheimer’s.
Studying mice, the researchers were able to simulate the effects of body cooling and pick apart the workings of a so-called “cold-shock” protein in the brain, RBM3, which has previously been linked with preventing brain cell death.
“We’ve known for some time that cooling can slow down or even prevent damage to brain cells, but reducing body temperature is rarely feasible in practice (because) it’s unpleasant and involves risks such as pneumonia and blood clots,” said Giovanna Mallucci who led the research.
“By identifying how cooling activates a process that prevents the loss of brain cells, we can now work toward finding a means to develop drugs that might mimic the protective effects of cold on the brain.”
Scientists already know that lowering body temperature can protect the brain. People can survive hours after a cardiac arrest with no brain damage after falling into icy water, for example, and artificially cooling brains of babies with oxygen deprivation at birth can also protect against brain damage.
Cooling - and hibernation in animals - prompts production of certain brain proteins known as “cold-shock” proteins. One of these, RBM3, has been linked with preventing the death of brain cells and synapses, but scientists are not sure how it works.
Knowing how these proteins affect synapse regeneration might help researchers find a way of mimicking them without the needing to cool the body down.
You may or may not appreciate sarcastic senses of humor, but sarcasm is a part of our culture. “We see it as a nice way to be critical and so we use it constantly, even when we are trying to be nice,” says Rankin, whose research found that people with both frontotemporal dementia (FTD) and Alzheimer’s disease tend to have a harder time picking up on sarcasm. Another unusual sign of dementia Rankin noticed? People with FTD couldn’t tell when someone was lying, although people with Alzheimer’s disease could tell. “FTD patients don’t have that sense anymore that things that people do could turn out badly,” she says.
Mallucci’s team reduced healthy mice’s body temperatures to 16-18 degrees Celsius - similar to that of a hibernating small mammal - for 45 minutes and found that the mice’s synapses dismantled on cooling and regenerated when re-warmed.
Constantly tripping over your own two feet? Everyone falls now and again - but frequent falling could be an early signal of Alzheimer’s disease, according to research. A 2011 study presented at Alzheimer’s Association International Conference in Paris looked at brain scans of 125 older adults and also asked them to keep track of how often they slipped and stumbled during an eight-month span. The results? Those participants who showed early signs of Alzheimer’s also happened to fall down more often. “People will come into our office concerned because they forgot what was on their grocery list last week, but when their spouse says they’ve fallen four times in the past year, that’s a sign of a problem,” says Rankin. People with this movement disorder, known as progressive supranuclear palsy, might not catch themselves on the way down either, making this dementia symptom even more dangerous.
The team then repeated the cooling in mice that had been specially bred with features of neurodegenerative diseases like Alzheimer’s and found the capacity for synapse regeneration fell as the disease progressed, and that RMB3 levels also dropped.
When the scientists artificially boosted levels of RBM3 they found it protected the Alzheimer’s mice, preventing synapse and brain cell depletion.
A Disregard for the Law
Some younger people in the beginning stages of early-onset dementia lose their sense of social norms. Shoplifting, breaking into someone’s house, and inappropriate interpersonal behaviors, such as sexual comments or actions, all make the list of surprising dementia symptoms - and they can lead to legal trouble, too. Early-onset dementia can hit people as early as their thirties and forties, well before anyone around them would consider their out-of-character, law-breaking behaviors as signs of dementia.
Hugh Perry, chairman of Britain’s Medical Research Council’s neurosciences and mental health board, which funded the research, said the finding may be important step forward.
One surprising early sign of dementia is eating nonfood objects or foods that are rancid or spoiled. This is partly because the person forgets what to do with the things in front of them. For example, dementia patients might try to eat the flower in a vase on a restaurant table because they “know they are there to eat, but don’t know what the flower is doing there,” says Rankin. Unlike some other Alzheimer’s symptoms or dementia symptoms, this one has few other likely explanations.
“We now need to find something to reproduce the effect of brain cooling. We need to find drugs which can induce the effects of hibernation and hypothermia,” he said.
Now and again, most people find themselves desperately searching for the right word. In fact, failing to find the word you are thinking of is surprisingly common and not necessarily a sign of dementia, says Rankin. But losing knowledge of objects - not just what they are called, but also what they are used for - is an early dementia symptom. Oddly enough, people who are losing this knowledge can be very competent in other areas of their lives.
By Madeline R. Vann, MPH
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