Functional activity and connectivity signatures of ketamine and lamotrigine during negative emotional processing: a double-blind randomized controlled fMRI study.
Translational psychiatry October 14, 2024 Marvin S Meiering, David Weigner, Matti Gärtner et al. 4 citations
In healthy adults, a single dose of ketamine reduced activity in the hippocampus and the default mode network (DMN) and increased connections between frontal and limbic brain regions while participants viewed emotional faces. These effects occurred both during the infusion and 24 hours later. Pretreatment with lamotrigine, which blocks glutamate release, prevented the increase in brain connectivity and the delayed reduction in DMN activity, but did not affect the acute drop in hippocampal and DMN activity. The findings suggest that ketamine's acute changes in brain connectivity and its sustained effects on DMN activity depend on glutamate transmission, whereas its immediate suppression of limbic and DMN activity does not.