REM sleep is associated with the volume of the cholinergic basal forebrain in aMCI individuals.

"Declarations Ethics approval and consent to participateParticipants were recruited in the context of four protocols between 2012 and 2020. All protocols were approved by institutional ethics committees (#2012–697, #12–13-008, #2010–468 and #MP-32–2018-1537), and written informed consent was obtained from each participant prior to the examinations, according to the declaration of Helsinki. Consent for publicationNot applicable. Competing interestsJulie Carrier: recipient of an investigator driven grant from Eisai (not linked to the present study). Other authors: none. Competing interests Julie Carrier: recipient of an investigator driven grant from Eisai (not linked to the present study). Other authors: none."

"Funding This research was funded by the Canadian Institutes of Health Research (CIHR) through a Foundation grant (FDN154291), Project grant (PJT153259) and Operating grants (MOP123294 and MOP102631). C.A. is supported by postdoctoral fellowships from the Fonds de Recherche du Québec – Nature et Technologies through the Merit scholarship program for foreign students (PBEEE), the Fonds de Recherche du Québec – Santé and Quebec Bio-Imaging network. MEMD was supported with a doctoral fellowship from the CIHR and the Fonds de Recherche du Québec – Santé. NG holds a Canada Research Chair in sleep disorders and brain health. JM holds a Canada Research Chair in Sleep Medicine."