Enhanced brain performance in mice following postnatal stress

Area of Science:

• Neuroscience
• Endocrinology
• Metabolic Disorders

Background:

• The double postnatal stress model (maternal separation and sham injection) in mice mimics type 2 diabetes-like metabolic alterations.
• Investigating stress-induced brain metabolic and functional changes is crucial for understanding diabetes comorbidities.

Purpose of the Study:

• To determine if postnatal stress induces brain metabolic-functional alterations linked to diabetes.
• To ascertain if these alterations are modulated by the opioid and/or ACTH-corticosterone systems.

Main Methods:

• Adult male mice underwent a double postnatal stress protocol.
• Neurophysiologic-neurometabolic parameters were assessed, including visual evoked potentials and NAD(P)H autofluorescence.
• Mice received postnatal treatments with naloxone (opioid antagonist) or antisense (AS) targeting proopiomelanocortin mRNA.

Main Results:

• Postnatal stress led to diabetes-like metabolic changes and enhanced brain performance (decreased visual evoked potential latency, increased NAD(P)H signals, improved passive avoidance learning, elevated brain-derived neurotrophic factor).
• Naloxone partially prevented stress-induced alterations.
• AS treatment normalized all parameters, indicating roles for both opioid and ACTH-corticosterone systems.

Conclusions:

• The stress model induces diabetes-like metabolic alterations coupled with enhanced brain neurometabolic-neurophysiologic performances, suggesting an 'enduring acute-stress' response.
• These findings highlight the differential modulation of stress-induced neuro-metabolic changes by endogenous opioid and corticosteroid systems.
• Prolonged imbalances may lead to later-life diabetes complications.