Editorial: Siegfried Hoyer's concept of Alzheimer pathophysiology.

The concept of central insulin resistance and dysfunctional insulin signaling in Alzheimer's Disease (AD) has been developed by Siegfried Hoyer in 1985-2000. It is widely recognized that the mechanisms underlying neuronal energy deficiency and in particular to elucidate insulin/insulin receptor cascade deficiencies are some of the most relevant proximate characteristics of sporadic AD. The imbalance between cerebral oxygen utilization and cerebral glucose utilization may cause rise in reactive oxygen species production and this might be causal for synapse degeneration. This concept has been substantiated by work on postmortem Alzheimer brains and has been translated back into the streptozotozin animal model, which has stimulated much further research by other researchers. Finally, the insulin hypothesis of Alzheimer's disease has currently advanced into a potential therapeutic avenue.