John M. Talmadge, M.D.

A Blog Covering Many Topics

New Brain Discovery? Lymph!

Although we don't know for certain that new treatments are just over the horizon, here's some potentially exciting news. Scientists at the University of Virginia have discovered previously unknown lymphatic vessels in the outer layers of the brain. These vessels appeared to link the brain and spinal cord with the rest of the body’s immune system. This study used mice and human samples, vessel structure was investigated in the mice, and the observations followed up in the human samples. This was an animal study using mice to investigate the structure and function of lymphatic vessels in the brain. In fact, this story has been circulating for awhile, but recently it's been highlighted in several stories. The good news is that this may mean that the original studies are standing up to scrutiny by other scientists.

The discovery may require a reassessment of our assumptions about lymph drainage in the brain and its role in diseases involving brain inflammation or degeneration, such as Alzheimer’s disease and multiple sclerosis. The study was published in the peer-reviewed scientific journal Nature.

When I was in medical school, we were taught that the central nervous system (brain and spinal cord) did not have a typical lymphatic drainage system. Lymph is the immune fluid that circulates through the body, containing white blood cells to fight infection and destroy abnormal cells. This study aimed to look at the circulation of lymph in the mouse brain, but mice and humans do not have identical biology, so the findings may not be directly applicable. 

The study involved complex laboratory techniques, using a fluorescent antibody to assess the alignment of cells within the brain, examination for markers associated with a lymphatic drainage system and looking at the functional capacity of identified vessels to carry lymphatic fluid to and from the brain. 
Human samples taken from the brain at autopsy were used to investigate any structures found in mice.

The scientists found that the outer protective layers of the mouse brain showed cells that were clearly lined up, which suggested that these were vessels with a unique function. These cells showed the characteristic features of functional lymphatic vessels. These vessels appeared able to carry both fluid and immune cells from the fluid surrounding the brain and spinal cord (the cerebrospinal fluid), and were connected to the lymph nodes in the neck. The location of these vessels may have been the reason they have not been discovered before, thereby causing the belief that there is no lymphatic drainage system in the brain.

This may mean current thinking about how the brain works needs to be reassessed. The researchers go on to say it could be the malfunction of these vessels that could be the cause of a variety of brain disorders, such as multiple sclerosis and Alzheimer’s disease.

Summary: This mouse study has examined the circulation of lymph in the brain. It discovered previously unknown lymphatic vessels in the outer layers of the mouse brain. If accurate, the findings may call for a review of how the immune system in the brain functions, and shed new light on its role in brain diseases involving brain inflammation or degeneration. Though animal research can give a good insight into biological and disease processes, and how they may work in humans, the processes in humans and mice are not identical. Further studies are needed to confirm these findings and to assess whether this knowledge is transferable to humans. As such, it is too early to say whether the findings could one day have any implications for the treatment of degenerative brain conditions such as multiple sclerosis or Alzheimer’s.  

The original article in Nature can be found here.

Change Your Brain

And now…a word or two about good science and having a healthy brain. We offer a range of programs at the Brain Performance Institute to help people of all ages and conditions improve and extend peak brain performance throughout their lives. By evaluating brain fitness and applying proven brain-training methods, the Brain Performance Institute will train individuals to think smarter and exploit their greatest natural resources — their brains.

BRAINHEALTH PHYSICALS
A unique cognitive assessment that measures cognitive reserve in pivotal areas of higher-order mental functioning, all of which rely on robust frontal lobe function. It is just as essential to measure and monitor brain fitness as it is to measure and monitor physical fitness. Get a benchmark of your brain’s health.

HIGH PERFORMANCE BRAIN TRAINING
The high performance brain training program, Strategic Memory Advanced Reasoning Training (SMART®Winking, was developed by Center for BrainHealth cognitive neuroscientists and is based on more than 25 years of scientific study. The training program targets improvement in the frontal lobe of the brain and is based on cognitive neuroscience principles of how to build strategic thinking, advanced reasoning and innovative problem-solving skills. SMART sessions include personalized training materials and integrated practice sessions.

I joined the staff at The Center for BrainHealth and BPI after extensive contact with the scientists and clinicians there. Over a period of months I found myself returning at least once or twice weekly to attend a lecture, to discuss research, or to interact with my friends on The Warrior Team, a powerful resource for veterans. I remember the day in November 2014 when I spoke with Dr. Sandra Chapman, the CEO, and she asked me whether I was enjoying my visits. "Are you kidding me?" I said, "I want to be more than a visitor—I want to work here!" Needless to say, I was both honored and extremely delighted when, early in 2015, I got the call and the invitation to be Senior Medical Advisor for CBH and BPI.

Changing the Brain

Current neuroscience reveals that both psychotherapy and psychiatric medications produce positive changes in the brain. Research at UCLA demonstrates that people who suffered from depression had abnormally high activity in the prefrontal cortex.  Psychotherapy patients who improved show more nearly normal brain activity in this hyperactive region. For obsessive-compulsive disorder, OCD, cognitive behavior therapy (CBT) was associated with a decrease in the hyperactivity of the caudate nucleus, and the effect was most evident in people who had a good response to CBT.  In other words, the better the therapy seemed to work, the more the brain activity changed.
People with chronic fatigue syndrome (CFS) tend to have a decrease in a type of brain tissue called grey matter in the prefrontal cortex of the brain.  OCD researchers in the Netherlands provided 16 sessions of CBT, and found significant increases in gray matter volume in the prefrontal cortex.  This seems to suggest that the CFS patients were able to “recover” some gray matter volume after CBT.

The bottom line: Although medication and psychotherapy appear to work their magic in difference places, the results are positive for both. The mechanism of action remains unclear, but studies also show that the combination of psychotherapy and the right medication (getting it right is very important!) is an excellent approach for many individuals. As the brain changes, we see the production of new proteins, which change our brains through neuroplasticity.   In selecting a treatment strategy, sometimes medication works best, sometimes psychotherapy is the best option, and sometimes it’s a combination of the two. 

Neuroscience of Belief

In the current issue of New Scientist I came across a good article on the neuroscience of belief. Graham Lawton writes, in part: Beliefs define how we see the world and act within it; without them, there would be no plots to behead soldiers, no war, no economic crises and no racism. There would also be no cathedrals, no nature reserves, no science and no art. Whatever beliefs you hold, it's hard to imagine life without them. Beliefs, more than anything else, are what make us human. They also come so naturally that we rarely stop to think how bizarre belief is.
In 1921, philosopher Bertrand Russell put it succinctly when he described belief as "the central problem in the analysis of mind". Believing, he said, is "the most 'mental' thing we do" – by which he meant the most removed from the "mere matter" that our brains are made of. How can a physical object like a human brain believe things? Philosophy has made little progress on Russell's central problem. But increasingly, scientists are stepping in.
The neuroscientific investigation of belief began in 2008, when Sam Harris (Harris, S., Sheth, S. A. and Cohen, M. S. (2008), Functional neuroimaging of belief, disbelief, and uncertainty. Ann Neurol., 63: 141–147) at the University of California, Los Angeles, put people into a brain scanner and asked them whether they believed in various written statements. Some were simple factual propositions, such as "California is larger than Rhode Island"; others were matters of personal belief, such as "There is probably no God". Harris found that statements people believed to be true produced little characteristic brain activity – just a few brief flickers in regions associated with reasoning and emotional reward. In contrast, disbelief produced longer and stronger activation in regions associated with deliberation and decision-making, as if the brain had to work harder to reach a state of disbelief. Statements the volunteers did not believe also activated regions associated with emotion, but in this case pain and disgust.

To read the full article, click here.