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.
Translational psychiatry
June 18, 2024
Matti Gärtner, Anne Weigand, Marvin Sören Meiering et al.
1 citation
Ketamine reduces spontaneous brain activity in three subregions of the anterior cingulate cortex (ACC) during administration in healthy people. Lamotrigine, which inhibits glutamate release, attenuates this effect only in the ventral ACC subregions, suggesting glutamate involvement there. ACC activity returns to baseline 24 hours later, though group differences persist between the lamotrigine and ketamine groups. Trait negative emotionality is closely linked to activity changes in the subgenual ACC after ketamine. These findings clarify how ketamine affects different ACC subregions and may relate to its antidepressant mechanisms.
Journal of psychopharmacology (Oxford, England)
June 19, 2025
David Weigner, Marvin Sören Meiering, Anne Weigand et al.
Ketamine infusion significantly increased functional connectivity between the pregenual anterior cingulate cortex and the dorsomedial prefrontal cortex during a working memory task, and between the pregenual anterior cingulate cortex and the left insula during rest. These effects were absent when participants were pretreated with lamotrigine, a glutamate-release inhibitor. The findings suggest that ketamine's beneficial effects on brain communication, observed in psychiatric conditions linked to chronic stress, may depend on glutamate release.