Altered thalamocortical functional connectivity by propofol anesthesia in rats

Area of Science:

• Neuroscience
• Anesthesiology
• Functional Neuroimaging

Background:

• Anesthesia involves central nervous system suppression, with mechanisms not fully understood.
• Propofol is a widely used sedative-hypnotic anesthetic.
• Thalamocortical connectivity's role in anesthesia requires further investigation.

Purpose of the Study:

• To investigate the effect of propofol on thalamocortical functional connectivity in rats.
• To explore the relationship between propofol dosage and brain network activity.
• To assess the utility of functional connectivity magnetic resonance imaging (fcMRI) in studying anesthetic effects.

Main Methods:

• Utilized functional connectivity magnetic resonance imaging (fcMRI) on a 3.0-tesla MR scanner.
• Administered intraperitoneal injections of propofol (80 mg/kg or 160 mg/kg) to Sprague-Dawley rats.
• Analyzed synchronized low-frequency fluctuations (LFF) of blood oxygen level-dependent (BOLD) signals.

Main Results:

• Synchronized LFF of BOLD signals between thalamic and somatosensory cortices (S1/S2) observed at 80 mg/kg propofol.
• Disappearance of synchronized LFF of BOLD signals at 160 mg/kg propofol.
• Evidence of regionally specific long-range correlations in spontaneous BOLD signal fluctuations within somatosensory networks.

Conclusions:

• Thalamocortical connectivity plays a significant role in propofol-induced anesthesia.
• Propofol dosage influences thalamocortical functional connectivity.
• fcMRI is a viable technique for investigating correlated fluctuations in brain networks during anesthesia.