Abstract
A few studies have compared the static functional connectivity between awake and anaesthetized states in rodents by resting-state fMRI. However, impact of anaesthesia on static and dynamic fluctuations in functional connectivity has not been fully understood. Here, we developed a resting-state fMRI protocol to perform awake and anaesthetized functional MRI in the same mice. Static functional connectivity showed a widespread decrease under anaesthesia, such as when under isoflurane or a mixture of isoflurane and medetomidine. Several interhemispheric connections were key connections for anaesthetized condition from awake. Dynamic functional connectivity demonstrates the shift from frequent broad connections across the cortex, the hypothalamus, and the auditory-visual cortex to frequent local connections within the cortex only. Fractional amplitude of low frequency fluctuation in the thalamic nuclei decreased under both anaesthesia. These results indicate that typical anaesthetics for functional MRI alters the spatiotemporal profile of the dynamic brain network in subcortical regions, including the thalamic nuclei and limbic system.
Highlights
Resting-state fMRI was compared between awake and anaesthetized in the same mice.
Anaesthesia induced a widespread decrease of static functional connectivity.
Anaesthesia strengthened local connections within the cortex.
fALFF in the thalamus was decreased by anaesthesia.
Competing Interest Statement
The authors have declared no competing interest.
Abbreviations
- ACC
- anterior cingulate cortex
- AId
- dorsal agulanular insular cortex
- AIp
- posterior agulanular insular cortex
- AUDd
- dorsal auditory cortex
- AUDp
- primary auditory cortex
- AUD-VIS
- auditory-visual cortical network
- BOLD
- blood oxygenation level dependent
- CEA
- central amygdala
- CM
- centromedian nucleus
- DMN
- default mode network
- DMH
- dorsomedial hypothalamus
- ECT
- ectorhinal area
- ENTDL
- dorsolateral entorhinal cortex
- FC
- functional connectivity
- FD
- Framewise displacement
- FDR
- false discovery rate
- GU
- gustatory cortex
- Hypo
- hypothalamic network
- ICA
- independent component analysis
- Iso
- isoflurane
- LA
- lateral amygdala
- LASSO
- least absolute shrinkage and selection operator
- LCN
- lateral cortical network
- LHA
- lateral hypothalamus
- LN
- limbic network
- LSr
- lateral septal nucleus
- Med
- medetomidine
- MO(s)
- (secondary) motor cortex
- MPO
- medial preoptic area
- MSE
- minimum mean squared error
- NBS
- network based statistic
- PAG
- periaqueductal tract
- PH
- posterior hypothalamus
- PHd
- dorsolateral posterior hypothalamus
- PIR
- piriform cortex
- PO
- posterior complex
- POA
- preoptic area
- SSs
- secondary somatosensory cortex
- Tea
- temporal association area
- ThN
- thalamus
- VAL
- ventral anterior-lateral complex
- VM
- ventral medial nucleus
- VPL
- ventral posterolateral nucleus
- VPM
- ventral posteromedial nucleus
