General anaesthesia during infancy reduces white matter micro-organisation in developing rhesus monkeys

Area of Science:

• Neuroscience
• Developmental Neuroscience
• Neuroimaging

Background:

• Non-human primates are crucial models in neuroimaging research.
• General anesthesia or sedation is typically required for data acquisition in these studies.
• The cumulative effects of anesthetics on early brain development require thorough investigation.

Purpose of the Study:

• To evaluate the impact of ketamine, Telazol®, and isoflurane on early brain development in rhesus macaques.
• To assess the dose-dependent effects of repeated anesthetic exposures.
• To analyze changes in white matter microstructure following anesthetic exposure.

Main Methods:

• Diffusion MRI scans were analyzed from 43 rhesus macaques (12 or 18 months old).
• Data were collected from two independent primate colonies.
• Generalized linear models accounted for age and sex.

Main Results:

• Significant, widespread reductions in fractional anisotropy (FA) were observed.
• Increased axial, mean, and radial diffusivity correlated with FA reductions.
• Effects were dose-dependent, with up to 40% FA decrease in some regions.

Conclusions:

• Multiple exposures to common anesthetics induce marked changes in white matter microstructure.
• This study provides novel insights into anesthetic effects on the developing primate brain.
• Future research should investigate the potential for brain recovery from these white matter alterations.