Importantly, the magnitude of SWA has been causally linked to cortical BDNF expression.51, 52 People with disordered sleep are at increased risk for developing PTSD,53 and individuals with PTSD exhibit decreased SWA.54, 55 To investigate how loss of Bdnf exon-IV-containing transcripts impacts sleep physiology, we performed EEG recordings in a homecage environment with Bdnf-e4 and WT mice (experimental details in Supplementary Methods). Here, BDNF is linked to post-traumatic stress disorder.