Functional connectivity is preserved but reorganized across several anesthetic regimes

• Published in: NeuroImage (Orlando, Fla.) Vol. 219; p. 116945
• Main Authors: Becq, Guillaume J.-P. C., Habet, Tarik, Collomb, Nora, Faucher, Margaux, Delon-Martin, Chantal, Coizet, Véronique, Achard, Sophie, Barbier, Emmanuel L.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.10.2020; Elsevier Limited; Elsevier
• Subjects: Anesthesia; Anesthetics; Anesthetics, Inhalation - pharmacology; Anesthetics, Intravenous - pharmacology; Animal biology; Animals; Bioengineering; Brain - diagnostic imaging; Brain - drug effects; Brain mapping; Cerebral blood flow; Cerebral blood flow (CBF); Cerebrovascular Circulation - drug effects; Engineering Sciences; Etomidate - pharmacology; Experiments; Functional connectivity (FC); Functional magnetic resonance imaging; Hypotheses; Imaging; Isoflurane - pharmacology; Laboratory animals; Life Sciences; Magnetic Resonance Imaging; Medetomidine - pharmacology; Metabolism; Nerve Net - diagnostic imaging; Nerve Net - drug effects; Neural networks; Neurons and Cognition; neurosciences; Rat; Rats; Rats, Long-Evans; Respiration; Resting state functional magnetic resonance imaging (rs-fMRI); Signal and Image processing; Signal processing; Systemic variables; Urethane - pharmacology; Variables; Wavelet transforms; RR; SV; Rat; Systemic variables; CBF; rs-fMRI; HR; Cerebral blood flow (CBF); Temp; Resting state functional magnetic resonance imaging (rs-fMRI); FCS; Anesthesia; Functional connectivity (FC); BOLD; FC; cerebral blood flow (CBF); systemic variables; resting state functional magnetic resonant imaging (rs-fMRI); Cerveau de rat; rat; Imagerie fonctionnelle par résonance magnétique en temps réel; Variables systémiques; Anesthésie générale; functional connectivity (FC); anesthesia; Flux cérébral
• ISSN: 1053-8119; 1095-9572
• DOI: 10.1016/j.neuroimage.2020.116945

Under anesthesia, systemic variables and CBF are modified. How does this alter the connectivity measures obtained with rs-fMRI? To tackle this question, we explored the effect of four different anesthetics on Long Evans and Wistar rats with multimodal recordings of rs-fMRI, systemic variables and CBF. After multimodal signal processing, we show that the blood-oxygen-level-dependent (BOLD) variations and functional connectivity (FC) evaluated at low frequencies (0.031–0.25 ​Hz) do not depend on systemic variables and are preserved across a large interval of baseline CBF values. Based on these findings, we found that most brain areas remain functionally active under any anesthetics, i.e. connected to at least one other brain area, as shown by the connectivity graphs. In addition, we quantified the influence of nodes by a measure of functional connectivity strength to show the specific areas targeted by anesthetics and compare correlation values of edges at different levels. These measures enable us to highlight the specific network alterations induced by anesthetics. Altogether, this suggests that changes in connectivity could be evaluated under anesthesia, routinely used in the control of neurological injury. [Display omitted] •Different anesthetics lead to different systemic and brain alterations.•BOLD variations and functional connectivity are affected by anesthesia.•Systemic variables have little influence on functional connectivity.•Baseline cerebral blood flow has no influence on functional connectivity.•Anesthetics reshape distributions of connections.