Sex-Specific Relationships between Cerebral Cortex Metabolism, Behavior, and ECG Parameters in Rats under...

Area of Science:

• Neuroscience and Metabolism
• Sex Differences in Physiology
• Biochemical Adaptations

Background:

• Sex-specific interactions between neurosignaling and metabolic pathways are crucial for adaptation and therapeutic efficacy.
• Understanding these sex-specific interactions is key to explaining differences in physiological responses.
• Metabolic stress, induced by inhibiting the pyruvate dehydrogenase complex (PDC), serves as a model to study these interactions.

Purpose of the Study:

• To characterize sex-specific adaptive responses to metabolic stress by examining neurosignaling and metabolic pathway interactions.
• To investigate the systemic indicators of sex-specific adaptation in a rat model with inhibited brain pyruvate dehydrogenase complex (PDC).
• To analyze how inhibiting PDC affects neurosignaling, glutamate metabolism, and behavior in a sex-dependent manner.

Main Methods:

• Rats were administered intranasal methyl acetylphosphinate (MeAcP) or dimethyl acetylphosphonate (AcPMe2) to inhibit brain PDC.
• Biochemical parameters (glutamate, glutamine synthetase activity, TCA cycle enzymes) and physiological indicators (ECG, behavior) were measured 24 hours post-administration.
• Spearman's rank correlation coefficients were used to analyze relationships between measured parameters, assessing sex-specific correlations.

Main Results:

• Control animals showed no sex differences in biochemical or ECG parameters, but significant sex differences in behavioral parameters and correlation structures.
• Females exhibited strong correlations between ECG and glutamine synthetase (GS) activity, while males showed associations between ECG and malic enzyme (ME) activity.
• PDC inhibition induced sex-specific reorganizations in neurosignaling and glutamate metabolism, altering sex differences in behavior and revealing new sex-related differences in glutamate levels and enzyme activities.

Conclusions:

• The relationships among metabolic, behavioral, and ECG parameters are inherently sex-specific.
• Cerebral cortex homeostasis during PDC inhibition reshapes these sex-specific relationships, modifying baseline biochemical and behavioral characteristics.
• These findings underscore the importance of considering sex as a biological variable in understanding metabolic stress responses and neurosignaling.