title: State-dependent functional connectivity of rat olfactory system assessed by fMRI.
abstract: Functional connectivity between the piriform cortex and limbic and neocortical areas was assessed using functional magnetic resonance imaging (fMRI) of urethane anesthetized rats that spontaneously cycled between slow-wave and fast-wave states. Slow-wave and fast-wave states were determined indirectly through monitoring of respiration rate, which was confirmed to co-vary with state as determined by electrophysiological recordings. Previous electrophysiological data have suggested that the piriform cortex shifts between responsiveness to afferent odor input during fast-wave states and enhanced functional connectivity with limbic areas during slow-wave state. The present results demonstrate that fMRI-based resting state functional connectivity between the piriform cortex and both limbic and neocortical areas is enhanced during slow-wave state compared to fast-wave state using respiration as an indirect measure of state in urethane anesthetized rats. This state-dependent shift in functional connectivity may be important for sleep-dependent odor memory consolidation.
authors.affiliation: Emotional Brain Institute, Nathan S. Kline Institute for Psychiatric Research, USA. dwilson@nki.rfmh.org
authors.forename: D A
authors.initials: DA
authors.lastname: Wilson
authors.forename: M J
authors.initials: MJ
authors.lastname: Hoptman
authors.forename: S V
authors.initials: SV
authors.lastname: Gerum
authors.forename: D N
authors.initials: DN
authors.lastname: Guilfoyle
mesh_terms: D000818:Animals; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D009833:Olfactory Pathways / Q000502:physiology*; D051381:Rats; D020318:Rats, Long-Evans; D012143:Respiratory Physiological Phenomena / Q000187:drug effects; D012890:Sleep / Q000187:drug effects / Q000502:physiology*; D014520:Urethane / Q000494:pharmacology
chemical_list: D014520:Urethane