Background　The　basal　nucleus　of　Meynert　(BNM),　a　primary　source　of　cholinergic　projections　to　the　cortex,　plays　key　roles　in　regulating　the　sleep-wake　cycle　and　attention.　Sleep　deficit　is　associated　with　impairment　in　cognitive　and　emotional　functions.　However,　whether　or　how　cholinergic　circuit,　sleep,　and　cognitive/emotional　dysfunction　are　inter-related　remains　unclear.Methods　We　curated　the　Human　Connectome　Project　data　and　explored　BNM　resting　state　functional　connectivities　(rsFC)　in　relation　to　sleep　deficit,　based　on　the　Pittsburgh　Sleep　Quality　Index　(PSQI),　cognitive　performance,　and　subjective　reports　of　emotional　states　in　687　young　adults　(342　women).　Imaging　data　were　processed　with　published　routines　and　evaluated　at　a　corrected　threshold.　We　assessed　the　correlation　between　BNM　rsFC,　PSQI,　and　clinical　measurements　with　Pearson　regressions　and　their　inter-relationships　with　mediation　analyses.Results　In　whole-brain　regressions　with　age　and　alcohol　use　severity　as　covariates,　men　showed　lower　BNM　rsFC　with　the　posterior　cingulate　cortex　(PCC)　in　correlation　with　PSQI　score.　No　clusters　were　identified　in　women　at　the　same　threshold.　Both　BNM-PCC　rsFC　and　PSQI　score　were　significantly　correlated　with　anxiety,　perceived　stress,　and　neuroticism　scores　in　men.　Moreover,　mediation　analyses　showed　that　PSQI　score　mediated　the　relationship　between　BNM-PCC　rsFC　and　these　measures　of　negative　emotions　bidirectionally　in　men.Conclusions　Sleep　deficit　is　associated　with　negative　emotions　and　lower　BNM　rsFC　with　the　PCC.　Negative　emotional　states　and　BNM-PCC　rsFC　are　bidirectionally　related　through　poor　sleep　quality.　These　findings　are　specific　to　men,　suggesting　potential　sex　differences　in　the　neural　circuits　regulating　sleep　and　emotional　states.