Paper Info
Title
Ketamine interactions with biomarkers of stress: A randomized placebo-controlled repeated measures resting-state fMRI and PCASL pilot study in healthy men.
Abstract
Ketamine, an NMDA receptor antagonist, is increasingly used to study the link between glutamatergic signaling dysregulation and mood and chronic pain disorders. Glutamatergic neurotransmission and stress corticosteroids (cortisol in human) are critical for Ca2+ mediated neuroplasticity and behavioral adaptation. The mechanisms of action of glutamatergic neurotransmission and stress corticosteroids on the NMDA-receptors of the hippocampus have been long investigated in animals, but given little attention in human studies. In this randomized single-blinded placebo-controlled crossover study (12 healthy young men), five sets of resting-state fMRI (RSFMRI), pseudocontinuous arterial spin labeling (PCASL), and corresponding salivary cortisol samples were acquired over 4h, at given intervals under pharmacokinetically-controlled infusion of subanesthetic ketamine (20 & 40mg/70kg/h). An identical procedure was repeated under a sham placebo condition. Differences in the profile of ketamine versus placebo effect over time were examined. Compared to placebo, ketamine mimicked a stress-like response (increased cortisol, reduced calmness and alertness, and impaired working memory). Ketamine effects on the brain included a transient prefrontal hyperperfusion and a dose-related reduction of relative hippocampal perfusion, plus emerging hyperconnectivity between the hippocampus and the occipital, cingulate, precuneal, cerebellar and basal ganglia regions. The spatiotemporal profiles of ketamine effects on different hippocampal subnetworks suggest a topographically dissociable change in corticohippocampal functional connectivity. We discuss our findings in the context of the negative feedback inhibition theory of the hippocampal stress-control. This pilot study provides a methodological framework for multimodal functional neuroimaging under resting-state conditions, which may be generalized for translational studies of glutamatergic- or stress-related etiology of neuropsychiatric disorders.
Year
DOI
Venue
2015
10.1016/j.neuroimage.2014.12.050
NeuroImage
Field
DocType
Volume
Developmental psychology,Neuroscience,NMDA receptor,Resting state fMRI,Psychology,Glutamatergic,Repeated measures design,Neuroplasticity,Hippocampus,Placebo,Ketamine
Journal
108
ISSN
Citations 
PageRank 
1053-8119
2
0.37
References 
Authors
8
11
Name
Order
Citations
PageRank
Najmeh Khalili-Mahani1476.02
Marieke Niesters230.72
Matthias J. P. van Osch3233.83
Melly Oitzl420.37
Ilya M Veer5273.08
d j de rooij6337.61
Joop van Gerven720.37
M A van Buchem818027.48
Christian F Beckmann91822115.17
serge a r b rombouts1010013.51
Albert Dahan1131.06