Deletion of serine racemase reverses neuronal insulin signaling inhibition by amyloid-β oligomers

Loss of brain energy metabolism control as a driver for memory impairment upon insulin resistance

The pathophysiological mechanisms intersecting metabolic and neurodegenerative disorders include insulin resistance, which has a strong involvement of environmental factors. Besides central regulation of whole-body homeostasis, insulin in the central nervous system controls molecular signalling that is critical for cognitive performance, namely signalling through pathways that modulate synaptic transmission and plasticity, and metabolism in neurons and astrocytes. This review provides an overview on how insulin signalling in the brain might regulate brain energy metabolism, and further identified molecular mechanisms by which brain insulin resistance might impair synaptic fuelling, and lead to cognitive deterioration.

Serine racemase modulation for improving brain insulin resistance: An Editorial Highlight for "Deletion of serine racemase reverses neuronal insulin signaling inhibition by amyloid-β oligomers"

This Editorial highlights an interesting study in the current issue of the Journal of Neurochemistry in which Zhou et al. report new data showing that the ablation of serine racemase increases local insulin production in neurons of the hippocampus. The authors explored some of the possible mechanisms mediating the interaction between dampening production of D-serine and the local synthesis of insulin, and they further propose that stimulating insulin production could counteract hippocampal insulin resistance in Alzheimer's disease (AD). Most importantly, they leave open a number of questions that need to be experimentally addressed to ascertain whether D-serine modulation of neuronal insulin expression can effectively improve insulin sensitivity in AD, as well as in metabolic disease with neurological impact.