PSEN1 and Alzheimer disease: In a double transgenic mouse model of AD co-expressing a mutant human amyloid-β protein precursor (AβPPswe) and presenilin 1 without exon 9 (PS1dE9), 4-phenylbutyrate and Wy-14,643 (two agonists of PPARα) reduced spatial memory loss and Aβ neuropathology, prevented tau phosphorylation (known to induce the formation of neurofibrillary tangles and neuropil threads during the progression of AD [24,25]), and mitigated the loss of the synaptic protein [26].