approximate invariance of metabolic energy per synapse during development in mammalian brains每个突触近似不变的代谢能量在哺乳动物大脑的发展.pdf

Approximate Invariance of Metabolic Energy per Synapse during Development in Mammalian Brains Jan Karbowski* Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences, Warsaw, Poland Abstract During mammalian development the cerebral metabolic rate correlates qualitatively with synaptogenesis, and both often exhibit bimodal temporal profiles. Despite these non-monotonic dependencies, it is found based on empirical data for different mammals that regional metabolic rate per synapse is approximately conserved from birth to adulthood for a given species (with a slight deviation from this constancy for human visual and temporal cortices during adolescence). A typical 3 : synapse uses about (7 +2) 10 glucose molecules per second in primate cerebral cortex, and about five times of that amount in cat and rat visual cortices. A theoretical model for brain metabolic expenditure is used to estimate synaptic signaling and neural spiking activity during development. It is found that synaptic efficacy is generally inversely correlated with average firing rate, and, additionally, synapses consume a bulk of metabolic energy, roughly 50 {90% during most of the developmental process (except human temporal cortex v50%). Overall, these results suggest a tight regulation of brain electrical and chemical activities during the formation and consolidation of neural connections. This presumably reflects strong energetic constraints on brain development. Citation: Karbowski J (2012) Approximate Invariance of Metabolic Energy per Synapse during Development in Mammalian Brains. PLoS ONE 7(3): e33425. doi:10.1371/journal.pone.0033425 Editor: Mohammed Akaaboune, University of Michigan, United States of America Receive