Author's reply.

to a decline in blood pressure? Furthermore, an exciting study in amyloid precursor protein transgenic mice found that noradrenaline depletion results in microglia dysfunction together with an increase in extracellular β-amyloid deposition, which can be rescued pharmacologically. It remains to be seen whether this finding can be translated into noradrenaline-based therapies for patients with dementia (for example noradrenaline reuptake inhibitors). Conceivably, the neuroprotective effects of noradrenaline may even extend beyond a single cellular mechanism or disease entity. Understanding the alterations in central noradrenaline signalling preceding overt dementia may create a powerful new window of opportunity for identifying both preclinical dementia stages and developing novel treatments targeting the locus coeruleus circuitry.