Non-signalling energy use in the brain.

Area of Science:

• Neuroscience
• Cell Biology
• Bioenergetics

Background:

• Brain energy consumption is substantial, with a large portion dedicated to non-signalling processes.
• Understanding these non-signalling energy demands is crucial for comprehending neuronal function and dysfunction.
• Existing data on the energetic costs of subcellular processes is fragmented and requires synthesis.

Purpose of the Study:

• To review experimental data and provide modeling estimates for non-signalling energy use in the brain.
• To assess the magnitude of ATP consumption by various subcellular processes.
• To explore how altered energy expenditure in these processes may impact neuronal function in disease.

Main Methods:

• Comprehensive review of existing experimental data on subcellular energy-consuming processes.
• Development of modeling estimates to quantify ATP consumption.
• Analysis of how pathological changes in these processes affect neuronal energy budgets.

Main Results:

• Significant uncertainty exists regarding the energy cost of actin treadmilling, with estimates varying widely.
• Microtubule treadmilling and protein synthesis appear to consume minimal brain energy.
• Lipid synthesis and mitochondrial proton leak are identified as major contributors to non-signalling energy expenditure.

Conclusions:

• The energetic contributions of non-signalling cellular processes to overall brain energy use are not well-defined.
• Further research is essential to accurately quantify these energy costs and their implications for brain health.
• Identifying and understanding these energy-intensive processes is key to addressing neurological disorders.