Less NMDA Receptor Binding in Dorsolateral Prefrontal Cortex and Anterior Cingulate Cortex Associated With Reported...

Area of Science:

• Neuroscience
• Psychiatry
• Toxicology

Background:

• Glutamate is a key excitatory neurotransmitter acting on N-methyl-D-aspartate (NMDA) receptors.
• Reduced NMDA receptor binding is observed in major depressive disorder and suicide.
• Early-life adversity (ELA) may contribute to glutamate-mediated excitotoxicity, a process implicated in depression and suicide.

Purpose of the Study:

• To investigate the association between NMDA-receptor binding, suicide, and ELA in postmortem human brain tissue.
• To determine if ELA influences NMDA-receptor binding independently of suicide status.

Main Methods:

• Postmortem brain tissue from 52 individuals (13 matched quadruplets of suicide and non-suicide decedents with or without ELA) was analyzed.
• NMDA receptor binding was quantified using [3H]MK-801 autoradiography in dorsal prefrontal (BA8, BA9) and anterior cingulate (BA24) cortex.
• Psychological autopsies were performed to ascertain psychiatric diagnoses and ELA history.

Main Results:

• [3H]MK-801 binding was not significantly different between suicide and non-suicide decedents across the studied brain regions.
• A significant reduction in [3H]MK-801 binding was observed in individuals with ELA, irrespective of suicide status, in BA8, BA9, and BA24.
• [3H]MK-801 binding showed no association with age or postmortem interval.

Conclusions:

• Reduced NMDA receptor binding in individuals with ELA supports the hypothesis that stress can lead to excitotoxicity.
• This excitotoxicity may result in NMDA receptor downregulation or neuronal loss, thereby decreasing receptor binding.
• Findings highlight the potential impact of ELA on glutamatergic neurotransmission and NMDA receptor function.