A recent study reveals that when the brain’s energy supply is depleted, such as during a stroke, neurons release glutamate in abnormal, self-amplifying bursts that can damage nerve cells.
Researchers from Ruhr University Bochum and the Universities of Düsseldorf and Twente used a fluorescent sensor to observe long-lasting, localized glutamate events that became more frequent under stress. The findings highlight how disrupted metabolism leads to excitotoxicity, worsening outcomes in conditions like stroke.
Under normal conditions, brain tissue is supplied with enough energy to regulate neurotransmitter release and reuptake. However, when the energy supply is depleted, this balance can quickly become disrupted. This is particularly concerning during strokes, where the blood supply to the brain is interrupted, leading to an increase in extracellular glutamate that severely impairs synapse function and nerve cell survival.
The study’s lead researcher, Dr. Tim Ziebarth, observed unusual glutamate release events that self-amplify under energy depletion conditions. These events, which are not typical for synaptic activity, occurred more frequently under stress and contributed to the accumulation of extracellular glutamate. The researchers also found that blocking NMDA receptors significantly reduced these harmful glutamate release events.
The study’s findings suggest a dangerous feedback loop between disrupted metabolism and excitotoxicity, highlighting the need for further research into how this type of release contributes to conditions like stroke and neurodegenerative diseases. Elevated glutamate concentrations are already known to be harmful to neurons, and this study provides new insights into the mechanisms underlying these conditions.
Source: https://neurosciencenews.com/neuroscience-glutamate-surge-28688