Correlations between alterations in TrkB signalling in Alzheimer’s disease [107,108], Huntington’s disease [109,110], Parkinson’s disease [111], Rett syndrome [112], traumatic brain injury, [113] and ageing [114] point to the therapeutic potential of TrkB agonists. This evidence concerns the gene NTRK2 and early-onset autosomal dominant Alzheimer disease.