News

A hyperactive brain in Alzheimer’s disease

Published Date:

Neurons are the cells responsible for communicating important information to different areas of the brain. They use various chemical messengers, called neurotransmitters, to pass information to one another.  The most abundant neurotransmitter in the brain is glutamate, a chemical on-switch that allows neurons to generate activity in other neurons. The brain needs glutamate for many different functions, including learning and memory. Still, too much of a good thing can become harmful— as is the case with this neurotransmitter.

In Alzheimer’s disease (AD), the brain accumulates too much glutamate, killing neurons and leading to memory loss. One possible initiator of this imbalance is soluble amyloid-beta 42 (Aβ42), a neurotoxic protein that accumulates overtime into the hallmark senile plaques seen in AD brains. Previous research from the Hascup laboratory has shown that soluble Aβ42 can activate neurons, causing them to release glutamate.

The most recent study in Scientific Reports by Dr. Kevin Hascup and colleagues shows how glutamate changes with amyloid pathology in AD mice. To study this, the team must use a biosensor that specifically measures glutamate inside the brain. Researchers placed the biosensor into the hippocampus, a brain structure important for learning and memory.  The results showed an increase in the amount of glutamate released by activated neurons that proceeded the appearance of amyloid plaques in the brain. As researchers progressed into late-stage AD, they observed high glutamate levels even when the neurons were resting. Now drowning in glutamate, neurons became burned out and released much less of the neurotransmitter when activated.  This imbalance hindered the necessary communication between neurons for learning and memory tasks. These findings suggest that amyloid pathology in AD may incite a shift in the brain’s glutamate balance, leading to cognitive decline. Further, this work provides evidence for the use of glutamate as a biomarker for therapeutic intervention strategies in AD.

More from SIU News

Maci Burgener and Evan Beilfuss

Baby med school on steroids leads to hometown health care

For many aspiring medical professionals, the journey to becoming a physician can feel like navigating a complex maze. For Evan Beilfuss and Maci Burgener, their paths converged at SIU School of
Aida lab

Alzheimer’s and cancer experts collaborate to study chemobrain

Research study will explore possible link with cytokine profiles, differences between men and women The Smith Alzheimer’s Center and Simmons Cancer Institute are teaming up to better understand the
Mandy Hagen

Strength in recovery: Letting lived experience lead the way

When Mandy Hagen stepped onstage to accept the Rising Star Award in addiction services, it marked a full-circle moment. Once unsure whether she deserved a seat at the table, today she’s leading recovery efforts across four counties in southern Illinois and inspiring others to find their way forward.