Press Releases & Research Commentary
March 7, 2013
A human glial cell (green) among normal mouse glial cells (red). The human cell is larger, sends out more fibers and has more connections than do mouse cells. Mice with this type of human cell implanted in their brains perform better on learning and memory tests than do typical mice.
For more than a century, neurons have been the superstars of the brain. Their less glamorous partners, glial cells, can't send electric signals, and so they've been mostly ignored. Now scientists have injected some human glial cells into the brains of newborn mice. When the mice grew up, they were faster learners. The study, published Thursday in Cell Stem Cell by Maiken Nedergaard, M.D., D.M.Sc. and Dr. Steven Goldman, M.D., Ph.D., not only introduces a new tool to study the mechanisms of the human brain, it supports the hypothesis that glial cells — and not just neurons — play an important role in learning.
Today, glial research and Dr. Goldman were featured on National Public Radio (NPR) speaking about the glial research that is outlined in this current publication.
I can't tell the differences between a neuron from a bird or a mouse or a primate or a human,says Goldman, glial cells are easy to tell apart.
Human glial cells — human astrocytes — are much larger than those of lower species. They have more fibers and they send those fibers out over greater distances.
In collaboration with the Nedergaard Lab, newborn mice had some human glial cells injected into their brains. The mice grew up, and so did the human glial cells. The cells spread through the mouse brain, integrating perfectly with mouse neurons and, in some areas, outnumbering their mouse counterparts. All the while Goldman says the glial cells maintained their human characteristics.
March 7, 2013
Glial cells – a family of cells found in the human central nervous system and, until recently, considered mere
housekeepers– now appear to be essential to the unique complexity of the human brain. Scientists reached this conclusion after demonstrating that when transplanted into mice, these human cells could influence communication within the brain, allowing the animals to learn more rapidly.
The study, out today in the journal Cell Stem Cell, suggests that the evolution of a subset of glia called astrocytes – which are larger and more complex in humans than other species – may have been one of the key events that led to the higher cognitive functions that distinguish us from other species.
The role of the astrocyte is to provide the perfect environment for neural transmission,said Maiken Nedergaard, M.D., D.M.Sc., co-senior author of the study and director, along with Dr. Steven Goldman, M.D., Ph.D., of the URMC Center for Translational Neuromedicine.
As the same time, we’ve observed that as these cells have evolved in complexity, size, and diversity – as they have in humans – brain function becomes more and more complex.
February 22, 2013
A novel way to image the entire brain's glymphatic pathway, a dynamic process that clears waste and solutes from the brain that otherwise might build-up and contribute to the development of Alzheimer's disease, may provide the basis for a new strategy to evaluate disease susceptibility, according to a research paper published online in the Journal of Clinical Investigation. Through contrast enhanced magnetic resonance imaging (MRI) and other tools, a Stony Brook University-led research team successfully mapped this brain-wide pathway and identified key anatomical clearance routes of brain waste.
In their article titled
Brain-wide pathway for waste clearance captured by contrast enhanced MRI,Principal Investigator Helene Benveniste, MD, PhD, a Professor in the Departments of Anesthesiology and Radiology at Stony Brook University School of Medicine, and colleagues built upon a previous finding by Jeffrey Iliff, PhD, and Maiken Nedergaard, MD, PhD, from University of Rochester that initially discovered and defined the glymphatic pathway, where cerebral spinal fluid (CSF) filters through the brain and exchanges with interstitial fluid (ISF) to clear waste, similar to the way lymphatic vessels clear waste from other organs of the body. Despite the discovery of the glymphatic pathway, researchers could not visualize the brain wide flow of this pathway with previous imaging techniques.
February 20, 2013
The brain and spinal cord are surrounded by cerebrospinal fluid, which provides a mechanically stable environment for these delicate structures against the forces of gravity and sudden acceleration and deceleration. Neurons and glia comprising the parenchyma of the brain are enveloped in their microenvironment by interstitial fluid. Interstitial fluid has long been considered to be unaffected by the production and flow of cerebrospinal fluid outside the brain parenchyma. However, two recent papers by Iliff et al. demonstrate that cerebrospinal fluid enters the deep substance of the brain, mixes with the interstitial fluid surrounding neurons and glia, and plays an important role in the exchange and clearance of molecules in the interstitial space of the central nervous system.
January 10, 2013
A new study out today in the journal Science turns two decades of understanding about how brain cells communicate on its head. The study demonstrates that the tripartite synapse – a model long accepted by the scientific community and one in which multiple cells collaborate to move signals in the central nervous system – does not exist in the adult brain.
Our findings demonstrate that the tripartite synaptic model is incorrect,said Maiken Nedergaard, M.D., D.M.Sc., lead author of the study and co-director of the University of Rochester Medical Center (URMC) Center for Translational Neuromedicine.
This concept does not represent the process for transmitting signals between neurons in the brain beyond the developmental stage.
- Fibroblast cytoskeletal remodeling induced by tissue stretch involves ATP signaling. J Cell Physiol. 228, 1922-6. (2013 Sep 01).
- Cellular control of connective tissue matrix tension. J Cell Biochem. 114, 1714-9. (2013 Aug 01).
- Improved axonal regeneration after spinal cord injury in mice with conditional deletion of ephrin B2 under the GFAP promoter. Neuroscience. 241, 89-99. (2013 Jun 25).