Background: The developmental transition from depolarizing to hyperpolarizing γ-aminobutyric acid-mediated neurotransmission is primarily mediated by an increase in the amount of the potassium-chloride cotransporter KCC2 during early postnatal life. However, it is not known whether early neuronal activity plays a modulatory role in the expression of total KCC2 mRNA and protein in the immature brain. As general anaesthetics are powerful modulators of neuronal activity, the purpose of this study was to explore how these drugs affect KCC2 expression during the brain growth spurt.
Methods: Wistar rat pups were exposed to either a single dose or 6 h of midazolam, propofol, or ketamine anaesthesia at postnatal days 0, 5, 10, or 15. KCC2 expression was assessed using immunoblotting, immunohistochemistry, or quantitative polymerase chain reaction analysis up to 3 days post-exposure in the medial prefrontal cortex.
Results: There was a progressive and steep increase in the expression of KCC2 between birth and 2 weeks of age. Exposure to midazolam, propofol, or ketamine up to 6 h at any investigated stages of the brain growth spurt did not influence the expression of this cotransporter protein.
Conclusion: I.V. general anaesthetics do not seem to influence developmental expression of KCC2 during the brain growth spurt.
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http://dx.doi.org/10.1093/bja/aet063 | DOI Listing |
Hum Brain Mapp
January 2025
FinnBrain Birth Cohort Study, Turku Brain and Mind Center, Department of Clinical Medicine, University of Turku, Turku, Finland.
The brain develops most rapidly during pregnancy and early neonatal months. While prior electrophysiological studies have shown that aperiodic brain activity undergoes changes across infancy to adulthood, the role of gestational duration in aperiodic and periodic activity remains unknown. In this study, we aimed to bridge this gap by examining the associations between gestational duration and aperiodic and periodic activity in the EEG power spectrum in both neonates and toddlers.
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