International audienceEndoplasmic reticulum (ER) dysfunction is important in the pathogenesis of many neurological diseases. In this review, we examine the evidence for ER dysfunction in a range of neurological conditions including cerebral ischaemia, sleep apnoea, Alzheimer's disease, multiple sclerosis, amyotrophic lateral sclerosis, the prion diseases and Familial Encephalopathy with Neuroserpin Inclusion Bodies (FENIB). Protein misfolding in the endoplasmic reticulum initiates a well-studied 'Unfolded Protein Response' in energy-starved neurones during stroke that is relevant to the toxicity of reperfusion. The toxic peptide Aβ induces 'ER stress' in Alzheimer's disease leading to activation of similar pathways, while the accumulation o...