The International Journal of Neuropsychopharmacology
August 10, 2022
Anne Weigand, Matti Gärtner, Milan Scheidegger et al.
22 citations
Activity in the pregenual anterior cingulate cortex (pgACC) during emotional stimulation can predict how well a single intravenous infusion of ketamine will relieve depression symptoms in people with major depressive disorder. In 24 patients, pgACC activity was linked to an increase in glutamate in the same brain region 24 hours after the infusion, and this glutamate increase was associated with greater symptom improvement. The findings suggest pgACC activity may serve as a neuroimaging biomarker for early treatment response to ketamine.
European Archives of Psychiatry and Clinical Neuroscience
January 12, 2022
Matti Gärtner, Anne Weigand, Milan Scheidegger et al.
13 citations
Ketamine's rapid antidepressant effects involve the glutamatergic system. A multimodal imaging study of 23 healthy volunteers used resting state fMRI and proton magnetic resonance spectroscopy to examine links between metabolic and functional brain changes during intravenous ketamine infusion. The pregenual anterior cingulate cortex (pgACC) was the focus. Functional connectivity changed from the pgACC to the right frontal pole and anterior mid cingulate cortex (aMCC). Absolute glutamate and glutamine concentrations in the pgACC did not differ significantly from baseline. Stronger pgACC activation during ketamine was linked to lower glutamine concentration, and reduced connectivity between pgACC and aMCC was related to increased pgACC activation and reduced glutamine.
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.
Pharmacopsychiatry
September 1, 2011
Simone Grimm, Milan Scheidegger, A Henning et al.
Ketamine, a glutamatergic NMDA receptor antagonist with rapid antidepressant properties, was used to investigate the neurobiology of major depressive disorder. In a multimodal imaging study of 23 healthy subjects, a single ketamine infusion increased negative BOLD responses in brain regions involved in emotional processing, particularly limbic areas linked to emotional information and higher-order mental functions. During cognitive processing, ketamine affected negative BOLD responses in anterior but not posterior regions of the default-mode network. Strong correlations were found between glutamate, glutamine, GABA, and glutamine/glutamate ratios and these brain responses after ketamine administration, suggesting a link to glutamatergic neurotransmission.