Cerebral Hemispheres 2
NEUROSCIENTIFICALLY CHALLENGED

NEUROSCIENCE MADE SIMPLER

A Triumph for Stem Cell Research


Although the potential applications of stem cell therapy are numerous, right now some of its most promising conceivable uses are in the treatment of degenerative brain disorders, such as Alzheimer’s disease (AD) or Parkinson’s disease (PD). In both of these afflictions, essential brain regions deteriorate, leading to notoriously debilitating symptoms. In AD, cholinergic neurons are depleted, while a loss of dopaminergic neurons is responsible for the effects of PD. Some scientists see disorders like these as ideal cases for stem cell treatment. For, in theory, if cholinergic or dopaminergic neurons are deteriorating, one could implant stem cells into the brain of the patient that could then be prodded to form new neurons. This could offset the atrophy caused by the disease.

Thus far, attempts to do this in laboratory animals have had mixed results. Sometimes a slight improvement can be seen, lending credence to the potential validity of the procedure. But failure for a diseased animal to get better after stem cell injection is more common, indicating there are problems with the technique. It is thought that those problems may have to do with the genetic compatibility of the stem cells being implanted into the subject’s brain and the subject's immune system. Perhaps the immune system is recognizing the stem cells as foreign and initiating a response to destroy them. This could be responsible for the animal’s lack of improvement.

Any scientists in training might want to pause for a moment before reading on and try to think about a logical solution to this problem. If a mouse’s immune system is rejecting stem cells from another mouse, what is a way to get around this?

The answer is: use stem cells genetically identical to the subject mouse’s cells. A group of researchers at Memorial Sloan-Kettering Cancer Center induced PD in mice by injecting them with a toxin. They then took skin cells from the tails of the mice and did a little DNA switcheroo. They took the DNA out of the skin cells and transferred it into mouse egg cells that had already had their own DNA extracted from them. The group then prodded the egg cells to divide, eventually producing stem cells as a part of normal embryonic development. The researchers added the appropriate growth factors to the stem cells to cause them to differentiate into brain cells.

They then injected the newly formed brain cells into the PD mice. The immune systems of the mice recognized the brain cells as “self”, since they were genetically identical. Thus, no immune response was mounted, and the mice showed significant neurological improvement. Out of about 100,000 genetically similar brain cells injected into each PD mouse, approximately 20,000 cells survived to function in each brain. Of course the study also had a group for comparison that received genetically dissimilar cells, and these mice did not get healthier. Only a few hundred of the genetically different cells survived in the brains of the mice in this group (of the same number injected).

This is what stem cell researchers have been waiting for: the use of somatic cell nuclear transfer (cloning) technology to make replacement cells for the body, resulting in clear evidence that it can lead to significant recovery from degenerative disorders. It is vindication for those who have been proclaiming the limitless possibilities of stem cells.

It, however, does not get around the fundamental problem stem cell advocates face. It requires the use of embryonic cells to create the stem cells. Thus, despite the potential it has, it will continue to face harsh political opposition. One has to hope, however, that as these procedures become perfected in organisms like mice, opponents will have to adopt a more utilitarian perspective. Perhaps using some of the half a million frozen embryos that are collecting dust in the in vitro fertilization clinics across the country would be considered a little more in depth if their ability to alleviate the suffering of living PD sufferers, which number over a million in the U.S. alone, had been demonstrated repeatedly in animal studies.

For other posts from me on stem cells, go here or here.

YOUR BRAIN, EXPLAINED

Sleep. Memory. Pleasure. Fear. Language. We experience these things every day, but how do our brains create them? Your Brain, Explained is a personal tour around your gray matter. Building on neuroscientist Marc Dingman’s popular YouTube series, 2-Minute Neuroscience, this is a friendly, engaging introduction to the human brain and its quirks using real-life examples and Dingman’s own, hand-drawn illustrations.

  • Reading like a collection of detective stories, Your Brain, Explained combines classic cases in the history of neurology with findings stemming from the latest techniques used to probe the brain’s secrets. - Stanley Finger, PhD, Professor Emeritus of Psychological & Brain Sciences, Washington University (St. Louis), author, Origins of Neuroscience

  • An informative, accessible and engaging book for anyone who has even the slightest interest in how the brain works, but doesn’t know where to begin. - Dean Burnett, PhD, author, Happy Brain and Idiot Brain

  • ...a highly readable and accessible introduction to the operation of the brain and current issues in neuroscience... a wonderful introduction to the field. - Frank Amthor, PhD, Professor of Psychology, The University of Alabama at Birmingham, author, Neuroscience for Dummies

  • Dingman weaves classic studies with modern research into easily digestible sections, to provide an excellent primer on the rapidly advancing field of neuroscience. - Moheb Costandi, author, Neuroplasticity and 50 Human Brain Ideas You Really Need to Know

BIZARRE

This book shows a whole other side of how brains work by examining the most unusual behavior to emerge from the human brain. In it, you'll meet a woman who is afraid to take a shower because she fears her body will slip down the drain, a man who is convinced he is a cat, a woman who compulsively snacks on cigarette ashes, and many other unusual cases. As uncommon as they are, each of these cases has something important to teach us about everyday brain function.

  • Dingman brings the history of neuroscience back to life and weaves in contemporary ideas seamlessly. Readers will come along for the ride of a really interesting read and accidentally learn some neuroscience along the way. - Erin Kirschmann, PhD, Associate Professor of Psychology & Counseling, Immaculata University

  • A unique combination of storytelling and scientific explanation that appeals to the brain novice, the trained neuroscientist, and everyone in between. Dingman explores some of the most fascinating and mysterious expressions of human behavior in a style that is case study, dramatic novel, and introductory textbook all rolled into one. - Alison Kreisler, PhD, Neuroscience Instructor, California State University, San Marcos

  • Through case studies of both exceptional people as well as those with disorders, Bizarre takes us on a fascinating journey in which we learn more about what is going on in our skull. - William J. Ray, PhD, Emeritus Professor of Psychology, The Pennsylvania State University, author, Abnormal Psychology

  • Bizarre is a collection of stories of how the brain can create zombies, cult members, extra limbs, instant musicians, and overnight accents, to name a few of the mind-scratching cases. After reading this book, you will walk away with a greater appreciation for this bizarre organ. If you are a fan of Oliver Sacks' books, you're certain to be a fan of Dingman's Bizarre. - Allison M. Wilck, PhD, Researcher and Assistant Professor of Psychology, Eastern Mennonite University