The question over the exact causes of Alzheimer’s disease has long been at the heart of research into the condition that affects so many of our loved ones. In a recent article by Lauren Horne, she details new research into the cause and possible treatment of Alzheimer’s disease. The study that was published in June 2014 in “Nature Medicine,” the well respected medical journal, examines the theorized effect of reactive astrocytes in the development of the disease. The study was carried out under the auspices of Drs. C. Justin Lee and Daesoo Kim in Korea and their paper was published with the title: “GABA from reactive astrocytes impairs memory in mouse models of Alzheimer’s disease.”
As described in the title of the paper, the focus of this research was centered around the effects of the reactive astrocytes. In particular, Lee and Kim pointed to the fact that these reactive astrocytes are often found in large percentages in the brains of patients with Alzheimer’s disease and are known to produce GABA, a neurotransmitter inhibitor. As they found that the reactive astrocytes were producing the GABA through Monoamine oxidase B(MAO-B), an enzyme that then passed on the GABA into the system through the BESt1 channel, they decided to target the B(MAO-B) in their testing.
What they found was that when they used the Parkinson’s disease drug Selegiline as an inhibitor to bring the levels of the GABA back to more normal numbers, they were able to succeed in slowing down the firing of neurons in the brain. In their tests that they carried out on mice with Alzheimer’s disease in the labs, those subjects who received the inhibitor treatment exhibited signs of improved memory that were consistent with their theory.
Unfortunately these results did not leave any lasting changes on the mice as the effect of the drugs wore off. However, to all those who are invested in finding a cure for Alzheimer’s disease, this study has provided valuable knowledge and new insights that may soon lead to a treatment.
Manipulation of Reelin signaling offers hope for reversing cognitive function of Alzheimer’s patients
A new study from Cell Biology Department scientists at the University of Barcelona working with laboratory mice sheds new light on the role that the protein Reelin plays in preserving plasticity in adult brains and restoring lost cognitive function. These findings were recently published in the periodical, Nature Connections, and are critical to the efforts to prevent and treat Alzheimer’s disease.
In spite of years of research seeking to locate the cause of Alzheimer’s disease, scientists still do not know the cause of this neurodegenerative ailment. However there are some known structures that appear to have a significant role in causing loss of cognitive function, neuronal death and decrease in synaptic functioning. These structures are amyloid plaques and neurofibrillary tangles. The new study reveals that when levels of Reelin were increased in the brain of laboratory mice with Alzheimer’s, cognitive loss was reversed. Further, it was confirmed that Reelin diminishes amyloid deposits and postpones the development of amyloid-beta fibril in vitro.
The role of Reelin in controlling tau protein and the amyloid precursor protein was already known, but the full extent of Reelin’s role was undiscovered. So, the researchers focused their efforts on analyzing Reelin’s role. With this new study, researchers working on prevention and treatment methodologies have a new comprehension of the bond between these two proteins and Reelin’s role in regulating them. The study proves that an increase in Reelin is beneficial to reversing the effects of Alzheimer’s disease.
Researchers discovered the nature of the interaction between Reelin in vitro and the peptide AB42, a lethal peptide responsible for the accumulation of senile plaques and formation of fibril. In vitro tests on mouse models revealed that Reelin was functioning to reduce plaque and delaying fibril formation. With these findings, researchers offer Reelin as a promoter of adult brain plasticity and protective agent for neurons. Future research will concentrate on identifying chemical composites that can stimulate Reelin signaling.