alzheimer’s disease

Study: Your Brain Makes Hundreds Of New Neurons A Day

(Digital Shotgun/flickr)

This just in from the journal Cell: Your hippocampus, a key region for memory in your brain, makes a few hundred new neurons every day.

Does this mean you can now drink Tequila shots with impunity because you can more than make up for the brain cells you damage? Nope, no reason to think so. But the findings in Cell could have implications for future research in areas from antidepressants to Alzheimer’s disease.

Mainly, the new study helps cement the long-controversial claim that new neurons keep a-borning in the human brain all through life. And it does so in a creative new way, using carbon-14 left in humans by above-ground nuclear tests in the mid-20th century to measure the ages of brain cells.

I asked Prof. Joshua Sanes, director of Harvard University’s Center for Brain Science, to explain what the study could mean — why it matters whether our hippocampi keep making new neurons or not. His reply, lightly edited:

The basic dogma of neurobiology has been that you’re born with all the neurons you’re ever going to get, and then everything goes downhill from there.

But there was heated debate about this, and eventually, it was found in experimental animals that you do actually get new neurons throughout life — but weirdly, only in a few places. Where would depend on the species, but for mammals like us, it’s your olfactory bulb — what the heck that is about, nobody has any idea — and the other place is the hippocampus.

The hippocampus has proven to be critical to memory, and I’m not sure whether you’d say memories are stored there, but they certainly seem to be made there. You probably know about the famous patient HM: When he lost his hippocampus, he lost his ability to make memories.

So the idea arose that maybe if you’re making new neurons in the hippocampus, that’s to help you make new memories. In mice, there’s some evidence that favors that idea. I think nobody thinks it’s going to be as simple as that — that every time you need a new memory, you make a new neuron — but there are lots of experiments where they prevent the making of new neurons and somehow degrade memory in mice. And it seems that a lot of the things that a mouse does can affect how many new neurons are made, or at least how many of the new neurons that are made wire up.

One of those things is exercise: if you exercise more, you make, or keep, more new neurons. If you suffer a lot of stress, you make fewer neurons. Depression has been implicated; nobody knows how but there’s some idea that antidepressants can help you make new neurons, and if you’re depressed, you make fewer neurons.

So people have been interested in these new neurons, but nobody knew whether they were made in the human hippocampus, and this new study tells you that they are. Continue reading →

FILED UNDER: Medicine/Science, Personal Health, Science, alzheimer's disease, depression, neuroscience

February 7, 2013 | 10:56 AM | Rachel Zimmerman

Report: Alzheimer’s Cases Could Triple By 2050

In the not-too-distant future, Alzheimer’s will likely get very personal for many more of us as the nation confronts an “epidemic” of the progressive brain disease, according to a new report based on 2010 census data. Cases of Alzheimer’s could nearly triple over the next 40 years, researchers say.

Here’s USA Today on the study, just published online in the journal Neurology:

Numbers are projected to rise from about 5 million now to 13.8 million. The disease robs people of their memory, erases personality and makes even routine tasks like dressing and bathing impossible.

Ann Gordon/flickr

“We’re going to need coordinated efforts for this upcoming epidemic,” says lead author Jennifer Weuve, assistant professor of medicine at Rush Institute for Healthy Aging in Chicago. “People have trouble getting their heads around these numbers, but imagine if everyone in the state of Illinois (population 12.8 million) had Alzheimer’s. I look around Chicago and can’t imagine it…”

Researchers analyzed information from 10,802 black and white Chicago residents, ages 65 and older, from 1993 to 2011. Continue reading →

FILED UNDER: Medicine/Science, Personal Health, aging, alzheimer's disease

July 24, 2012 | 1:18 PM | Karen Weintraub

Another Blow To Alzheimer’s Drug Development

Yet another drug that was hoped to fight Alzheimer’s has failed a crucial clinical trial – at least for patients with the genetic form of the brain disease.

For decades, doctors have been trying different approaches in their attack against Alzheimer’s, but so far, each one has failed. It’s not clear if that failure is due to the way science works – in which early tests are done on mice, whose brains are obviously less complex than people’s – or because patients aren’t treated until late in the disease, when extensive damage has already been done, or because of a lack of understanding of Alzheimer’s.

The latest approach, a drug called bapineuzumab made by Pfizer, Johnson & Johnson, and Irish pharmaceutical company Elan, was intended to go after beta amyloid, a protein that is toxic to brain cells and believed to be a primary driver of Alzheimer’s.

Dr. Reisa Sperling, director of the Center for Alzheimer Research and Treatment at Brigham and Women’s Hospital, told The New York Times that the drug failed to improve either day-to-day activities or brain power more than a placebo. Continue reading →

FILED UNDER: Medicine/Science, alzheimer's disease

January 13, 2012 | 12:45 PM | Carey Goldberg

Why To Exercise Today: Fight Your Genetic Risk Of Alzheimer’s (Maybe)

I know, we’ve already linked to this study on exercise and Alzheimer’s, but I just wanted to come back to it because the findings struck me as so dramatic. As Bloomberg reports:

Carriers of the Alzheimer’s gene APOE-4 who regularly exercised over a decade were five to 10 times less likely to have brain plaques linked to the disease than those with the gene who weren’t physically active.

It was only one study, and only followed a couple of hundred people, and a half dozen other caveats apply, but still, five to 10 times less likely to have brain plaques? If borne out, that is not minor.

When I see “APOE-4,” the well-established Alzheimer’s-risk gene that nearly a fifth of us carry, I think “Dr. Robert Green,” the Brigham & Women’s Hospital geneticist who has surely done more research than anyone on how people react when they find out they carry it. I wondered whether this study would affect what APOE-4 carriers are told when they find out they are at higher risk for Alzheimer’s — would they all be sent right to the gym?

In a word, no, but here’s Dr. Green’s bottom line: “As we get older, there are an awful lot of things that influence brain health. The way I think of it is that if you’ve got a disease that’s slowly brewing in your brain and you keep yourself as healthy as possible, and you keep the vascular load on top of that disease — the stuff gumming up the arteries in your brain — if you can keep that to a minimum, then with whatever genetic load you have, and whatever underlying developing disease you have, you do better.” Continue reading →

FILED UNDER: Medicine/Science, Personal Health, alzheimer's disease, why to exercise today

October 21, 2011 | 5:57 PM | Carey Goldberg

Literary Rx For Alzheimer’s Caregivers: The Prizewinning Candor Of ‘Keeper’

WBUR’s “Fade To Darkness” series on Alzheimer’s this week offers a highly helpful resource page here, including a list of books and even a link to an Alzheimer’s bookstore. But I’d like to add one personal recommendation for a book newly out in paperback: “Keeper,” by the British writer Andrea Gillies. It is literary alchemy: it takes the nightmare of a woman who makes the awful error of committing to take care of her mother-in-law with Alzheimer’s in a remote house in northern Scotland, and turns it into something beautiful. Beautifully expressed, that is. I suspect some among the legions of Alzheimer’s caregivers may not want to read any more about all-too-familiar daily challenges, but others may glory in seeing familiar thoughts and feelings so gratifyingly put into words. And they could use “Keeper” as a teaching tool to help others understand the strains of life in the Alzheimer’s trenches.

Here are several brief excerpts from “Keeper,” which won the 25,000-pound Wellcome Trust Book Prize in 2009. And at the end, I’ve added the 19th-century poem that Andrea Gillies uses to open the book. “Nancy” is the mother-in-law, “Chris” the husband.

If I had to pick one catch-all descriptor for Nancy’s life in the last few years it would be misery. Profound misery, unceasing and insoluble. She knows that something is wrong, very wrong, but what is it? She’s had a series of terrible daily encounters with herself and her environment that might have come directly from an amnesiac thriller: waking to find she has aged fifty years overnight, that her parents have disappeared, that she doesn’t know the woman in the mirror, nor the people who claim to be her husband and children, and has never seen the rooms and furnishings that everyone around her claims insistently are her home. Time has slipped, gone seriously askew. Every day for her is spent in an ongoing quest to put things right. The trouble is, she can’t seem to concentrate on the question or on possible clues to it. She can’t navigate the problem. When she left us for the nursing home, she was daily engaged in a very protracted, slow-motion form of panic. It’s been over eight years now since the formal diagnosis and eleven years at least since symptoms began, but even after all this time, she’s only at stage 6 of the disease. Stage 7 looms, the cruelest and last phase, with its loss of continence, motor control, speech and ability to swallow. Eventually her lungs will forget how to breathe, her heart forget how to beat, and her quest will come to an end.

(This scatological scene stuck in my mind for a long time — for both its actual and symbolic content:) Continue reading →

FILED UNDER: Medicine/Science, Personal Health, alzheimer's disease

October 21, 2011 | 3:34 PM | Carey Goldberg

When You Think It’s Alzheimer’s But It’s Not

For listeners who are now paranoid about Alzheimer’s Disease after this week’s WBUR series, one heartening response came from a colleague’s father, Dr. Jack N. Alpert, a Houston neurologist with 43 years of experience. He pointed out that though Alzheimer’s disease is indeed common, so is misdiagnosis. Of the many patients he has treated who were initially thought to have Alzheimer’s, he said, perhaps 5 to 10 percent of them turned out to have something else — often something far more treatable, like depression.

When Alzheimer’s is suspected, he noted, patients need a full work-up for other possible causes of their symptoms, checking everything from their sodium levels to their thyroid function, as well as an MRI scan of the brain. Other tests may also cast light on the patient’s condition, including a look at the spinal fluid, but in his experience, neuropsychological testing remains the gold standard for the diagnosis at this point.

“So instead of saying ‘shoe,’ he might say ‘flubscum.’”

So if a patient seems to have Alzheimer’s, with all the confusion and memory loss we’ve heard about so vividly this week, what else might it be?

Dr. Alpert listed the other possibilities in order of how common they are in his experience, with the most common first:

Depression

There is something called “pseudo-dementia of depression.” Patients are brought to me sometimes when their thinking has slowed, their movement has slowed down, and if you ask them, ‘Are you depressed?’ they might say ‘No,’ but their behavior suggests depression, and we call that ‘psychomotor retardation’: Slow thinking, slow responses.

Dr. Jack N. Alpert

You can often distinguish that from dementia because there’s a sleep disorder, insomnia, and lack of motivation, preference to stay in the house, loss of appetite, a facial expression which is sad. Those are things that raise the question of depression. So depression causes a type of dementia which is reversible with medical treatment.

Alcoholism

People who are heavy drinkers can show the same symptoms as Alzheimer’s, the same short-term memory loss. This is called “Korsakoff’s psychosis,” and it looks the same. Continue reading →

FILED UNDER: Medicine/Science, Personal Health, alzheimer's disease

October 16, 2011 | 4:51 PM | Carey Goldberg

Don’t-Miss Radio: WBUR Alzheimer’s Series Begins Monday

I know, I know: It’s depressing. But the coming wave of Alzheimer’s Disease looms so large that it is too important to ignore. Beginning tomorrow and every day next week, WBUR will be running a series of special reports on Alzheimer’s Disease, every day at 6:35 and 8:35 a.m. It will live on the Web here, and include stories from the public as well as reported pieces. The overview:

It is predicted to be the defining disease of the baby boom generation – Alzheimer’s – the incurable brain disorder that destroys memory, as well as the ability to speak and function. As the country’s 78 million baby boomers turn 65, the age when the disease significantly increases, cases of Alzheimer’s are expected to skyrocket.

According to the Alzheimer’s Association, ten million — or one in eight baby boomers — will develop Alzheimer’s. By the age of 85, nearly one in two will get the disease.

There is still no way to prevent or cure Alzheimer’s and experts warn that unless progress is made soon, the coming explosion of cases may be the greatest health crisis facing the nation, causing widespread suffering as well as huge strains on the country’s health care system.

And here are each day’s offerings:

10/17: Part 1, Ralph and Ruth

Dr. Ralph Kelly, a prominent cardiology researcher and former VP at Genzyme, was diagnosed with early- onset Alzheimer’s at age 59. With the diagnosis, Ralph’s active life as an executive, world traveler and father of four came to a halt. In part 1 of the series, we will get inside the Kelly family life to learn how they live with this life-altering disease. We talk to Ralph, who shares his first-hand experience of living with Alzheimer’s, as well as his wife Ruth, who must manage her husband’s care, her career and their three young children. Continue reading →

FILED UNDER: Medicine/Science, Money, alzheimer's disease

May 23, 2011 | 2:30 PM | Carey Goldberg

Rock Stars Of Brain Science Gather In Boston

I was remarking upon the truly astonishing line-up of luminaries attending Rep. Patrick Kennedy’s major brain conference in Boston today, launching an initiative that aims to take on the brain as a challenge on the scale of JFK’s drive to the moon 50 years ago. “It’s just about everybody who’s anybody,” I said — all the names of federal agency leaders and high-profile scientists I’d covered for years on the brain beat.

Yes, said another attendee, “They really brought out all the rock stars of brain science.”

So call me a groupie, but I homed in on one particular scientist whose work I’ve admired from afar but never covered: Dr. Karl Deisseroth of Stanford. He leads work that many see as a real game-changer in brain science. His best summary: “The combination of genetics and optics to achieve gain and loss of function.” My best simplification: You engineer neurons so that, say, green light turns them on, red light turns them off. Green light: scared. Red light: Not scared any more.

Here’s Karl kindly obliging with sound bites:

Many at the Kennedy conference have noted that the brain is frustratingly hard to experiment on, stuck as it is inside the skull and endlessly complex. Optogenetics lets us effectively turn things in the brain off and on, to test hypotheses, figure out how ciruits work and someday, perhaps, fix them.

Actually, for mice, that day may already have come. Karl Deisseroth’s team showed this spring that they could apparently reduce the anxiety of a mouse by manipulating it optogenetically. The Times reported earlier this month:

Treating anxiety no longer requires years of pills or psychotherapy. At least, not for a certain set of bioengineered mice. In a study recently published in the journal Nature, a team of neuroscientists turned these high-strung prey into bold explorers with the flip of a switch. The group, led by Dr. Karl Deisseroth, a psychiatrist and researcher at Stanford, employed an emerging technology called optogenetics to control electrical activity in a few carefully selected neurons.
First they engineered these neurons to be sensitive to light. Then, using implanted optical fibers, they flashed blue light on a specific neural pathway in the amygdala, a brain region involved in processing emotions.
And the mice, which had been keeping to the sides of their enclosure, scampered freely across an open space.

Obligatory disclaimer: Manipulating circuits in mice is a long way from doing it in humans. Continue reading →

FILED UNDER: Medicine/Science, Science, alzheimer's disease, anxiety, brain science, neuroscience, NIH, psychiatry

April 19, 2011 | 10:54 AM | Carey Goldberg

Q&A: State Of The Science On Early Alzheimer’s Disease

Even as I write this, I can feel the biological hallmarks of Alzheimer’s Disease building in my brain: the beta-amyloid plaques gumming it up, and the tau protein tangles snaking through the neurons. But a bit of paranoia is a small price to pay for the critical new understanding that scientists have gained about Alzheimer’s Disease in recent years: that the brain pathology begins long before the forgetfulness shows up. Early brain pathology means early detection is possible, and early detection means the potential for blocking the disease before it turns into the terrible dementia that affects millions.

Today is a landmark day for Alzheimer’s research: The first major new set of guidelines since 1984 on defining and diagnosing the disease has just been issued. The Alzheimer’s Association has posted them here, and both The New York Times and The Boston Globe do a nice job of summing them up. I spoke this morning with Dr. Reisa Sperling of Brigham & Women’s Hospital, lead author of today’s paper on the earliest, “pre-clinical” stage of Alzheimer’s Disease.

Dr. Reisa Sperling of Brigham & Women's

This is the first time in 27 years that the guidelines on Alzheimer’s have been re-issued. What are the biggest changes?

The biggest changes are that we’ve reconceptualized Alzheimer’s Disease as a continuum. The first criteria published in 1984 only dealt with Alzheimer’s Disease as a stage of dementia, which we now recognize to be at rather late stages of the disease process. The new criteria incorporate an earlier symptomatic stage called mild cognitive impairment due to Alzheimer’s Disease. And the earliest stage, which we have called pre-clinical Alzheimer’s Disease, is a new concept of the disease beginning in the brain prior to the clinical symptoms.

How would you sum up the state of the science on early detection of Alzheimer’s?

The pre-clinical stage is primarily detected through bio-markers. There have been tremendous advances over the past decade in being able to detect evidence of Alzheimer’s Disease in the brain during life. These include PET scans for amyloid, cerebrospinal fluid tests, and both functional and structural MRI scans.

Is there any one particular holy grail in terms of research on early detection of Alzheimer’s?

I don’t actually think it will be one thing. I think that we know from the autopsy data that there are actually several processes in the brain involved, and I suspect that we will need a combination of biomarkers to detect these processes. But the holy grail would be finding the combination of biomarkers in people who are still cognitively normal that accurately predicts who will progress to Alzheimer’s Disease dementia.

In terms of the existing ways for detecting Alzheimer’s Disease early, I gather none of them are ready for prime-time in the clinic? Continue reading →