Journal of Neuroscience
November 18, 2009
Angela R. Laird, Simon B. Eickhoff, Karl Li et al.
577 citations
The default mode network (DMN) is a set of brain regions active at rest and less active during many tasks, but these regions also show task-related increases. By combining activation likelihood estimation meta-analysis with the BrainMap database, core DMN regions were identified and their functional heterogeneity examined. Meta-analytic coactivation maps showed each region connects with both DMN and non-DMN areas. Behavioral domain analysis revealed that DMN subnetworks are differentially specialized: affective, perceptual, and motor-processing cliques were identified. The results provide a connectivity model of DMN interactions during diverse tasks.
Nature Neuroscience
January 28, 2025
Casey Paquola, Margaret Garber, Stefan Frässle et al.
58 citations
The default mode network (DMN) is a set of brain regions important for complex thought and behavior. By combining postmortem tissue analysis and brain scans, researchers found that the DMN contains different types of cells, some specialized for processing single senses, others for combining information, and still others for memory. The DMN includes regions that receive input from sensory areas and a core that is relatively cut off from direct sensory information. Analysis of how signals flow through the DMN showed it uniquely balances output across different levels of sensory processing. These findings provide a structural basis for understanding the DMN's broad role in brain function and cognition.
Human Brain Mapping
October 21, 2019
Bhim M. Adhikari, Juergen Dukart, Joerg F. Hipp et al.
24 citations
Ketamine, given at subanesthetic doses to healthy volunteers, produces psychosis-like symptoms and reduces functional connectivity in the salience network, auditory network, and default mode network (DMN). Midazolam, a sedative, only reduces DMN connectivity. The pattern of connectivity deficits caused by ketamine positively correlates with the pattern seen in schizophrenia, whereas midazolam's effects do not. After subtracting midazolam's effects, the remaining ketamine-specific disconnectivity pattern still correlates with schizophrenia deficits. This suggests that ketamine's psychosis-like effects have a brain functional basis that overlaps with schizophrenia-related connectivity disruptions.
Neuroscience and Biobehavioral Reviews
November 1, 2023
Sophia Linguiti, Jacob W Vogel, Valerie J Sydnor et al.
15 citations
A systematic review of 91 fMRI studies on acute psychedelic effects found substantial methodological heterogeneity. Only 51 unique samples were used across the 91 papers, and 54% of studies did not meet current standards for correcting Type I errors or controlling motion artifacts. Psilocybin and LSD consistently modulated connectivity along the sensorimotor-association cortical axis. Ketamine consistently increased activation in the dorsomedial prefrontal cortex. The review calls for future adoption of pre-registration, standardized processing and statistical testing, and data sharing to improve rigor.
medRxiv : the preprint server for health sciences
October 21, 2024
Pascal Grumbach, Jan Kasper, Joerg F. Hipp et al.
1 citation
preprint
Autism spectrum disorder involves altered resting-state brain function, and an imbalance between excitation and inhibition is a proposed mechanism. In two large independent cohorts, individuals with autism consistently showed reduced local brain activity in default mode network nodes and increased activity in temporal regions, cerebellum, and brainstem. These activity changes spatially overlapped with multiple neurotransmitter systems, including dopamine, glutamate, GABA, and acetylcholine. The NMDA-antagonist ketamine, but not the GABA-potentiator midazolam, induced activity changes resembling those seen in autism, suggesting that pharmacologically shifting the excitation-inhibition balance can mimic autism-related brain alterations.