Researchers at the Gladstone Institute of Neurological Disease (GIND) and Baylor College of Medicine have discovered a mechanism by which the protein Amyloid-beta(AB) may impair neurological functions in Alzheimer's disease. AB, which is known to accumulate in the brains of Alzheimer patients, has long been a focus of research into the causes and treatment of the disease. In a study published in the journal Neuron, Gladstone scientists found that A-beta triggers abnormal overexcitation of the very brain networks that are responsible for learning and memory.
"Such abnormal network activity in Alzheimer's patients was thought to be a collateral or secondary event caused by the degeneration of nerve cells," said Jorge J Palop, PhD, Gladstone research scientist and lead author of the study. "But our study suggests that this activity may actually be a primary effect of A-beta and an early determinant of cognitive failure."
The Gladstone team used several genetically engineered mouse models of AD in which memory deficits are triggered by a human gene that causes high levels of A-beta. They discovered that high levels of A-beta induce an insidious type of seizure activity in learning and memory centers that is not accompanied by the usual twitching and jerking movements seen in many forms of epilepsy. In fact, it took sophisticated brain wave recordings in freely behaving mice by electroencephalography (EEG) and telemetry to detect the seizure activity.
"We were really surprised by these findings because A-beta had previously been suspected to primarily suppress neuronal activity," said Lennart Mucke, MD, GIND director and professor of neurology and neuroscience at the University of California, San Francisco (UCSF), and senior author of the study. "This abnormal brain activity could play an important role in the development of Alzheimer-related cognitive impairments."
Physicians have long recognized that Alzheimer patients have a higher incidence of convulsive seizures than reference populations. The new study indicates that A-beta is to blame for this problem and raises the disconcerting possibility that these patients may also have non-convulsive seizures that could easily escape detection by standard clinical exams. The investigators are eager to test this hypothesis in a planned follow-up study of human subjects.
"Our results have important therapeutic implications, because the prevention and reversal of non-convulsive seizure activity has not yet been a major focus of clinical trials in Alzheimer's disease. Our results suggest that the suppression of this activity might prevent and possibly even reverse cognitive impairments induced by high levels of A-beta," said Dr. Mucke.
Valerie Tucker | EurekAlert!
Tracking movement of immune cells identifies key first steps in inflammatory arthritis
23.01.2017 | Massachusetts General Hospital
Team discovers how bacteria exploit a chink in the body's armor
20.01.2017 | University of Illinois at Urbana-Champaign
For the first time ever, a cloud of ultra-cold atoms has been successfully created in space on board of a sounding rocket. The MAIUS mission demonstrates that quantum optical sensors can be operated even in harsh environments like space – a prerequi-site for finding answers to the most challenging questions of fundamental physics and an important innovation driver for everyday applications.
According to Albert Einstein's Equivalence Principle, all bodies are accelerated at the same rate by the Earth's gravity, regardless of their properties. This...
An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...
Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...
Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.
While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...
Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales
Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...
19.01.2017 | Event News
10.01.2017 | Event News
09.01.2017 | Event News
23.01.2017 | Health and Medicine
23.01.2017 | Physics and Astronomy
23.01.2017 | Process Engineering