Neuropsychopharmacology : official publication of the American College of Neuropsychopharmacology
November 1, 2023
Daniel Ryskamp Rijsketic, Austen B Casey, Daniel A N Barbosa et al.
49 citations
Psilocybin increased neural activity (c-Fos expression) in the neocortex, caudoputamen, central amygdala, and parasubthalamic nucleus while decreasing it in the hypothalamus, cortical amygdala, striatum, and pallidum of mice, largely regardless of whether the mice were in their home cage or an enriched environment. Network analyses showed that psilocybin disrupted co-activity between highly correlated brain regions, reduced modularity, and attenuated communication between modules. Context and psilocybin each had widespread effects on brain activity and network architecture, but interactions between the two were surprisingly sparse.
Nature Communications
October 19, 2023
Laura M Hack, Xue Zhang, B. Heifets et al.
20 citations
Ketamine rapidly induces altered states of consciousness, but the neural mechanisms are unclear. In a randomized, placebo-controlled study with nonclinical adults, functional neuroimaging examined brain activity during emotional tasks under placebo, low-dose (0.05 mg/kg), and high-dose (0.5 mg/kg) ketamine. Different dissociative experiences had opposing effects on right anterior insula activity: depersonalization reduced task-evoked activity by 0.39 standard deviations, while dissociative amnesia increased it by 0.32 standard deviations. These findings suggest that specific dissociative states may influence how ketamine affects brain activity, potentially informing treatment responses in depression.
JAMA network open
April 1, 2025
Xue Zhang, Laura M Hack, Claire Bertrand et al.
10 citations
In a double-blind, placebo-controlled trial, 16 adults with subthreshold PTSD symptoms and early life trauma but no current psychiatric disorders were given 120 mg of MDMA or placebo. Participants were split into two groups based on baseline brain activity in the amygdala in response to nonconscious threat cues: those with high amygdala reactivity (NTNA+) and those with low reactivity (NTNA-). MDMA, compared with placebo, reduced activity in the amygdala and subgenual anterior cingulate cortex (sgACC), increased connectivity between the sgACC and amygdala, and increased liking of threatening facial expressions, but only in the NTNA+ subgroup. These findings suggest that baseline neural circuit profiles can identify who may benefit most from MDMA therapy and point to possible biomarkers for personalized treatment.
bioRxiv (Cold Spring Harbor Laboratory)
February 21, 2023
Daniel Ryskamp Rijsketic, Austen B. Casey, Daniel A. N. Barbosa et al.
10 citations
preprint
Psilocybin, given to mice in either their home cage or an enriched environment, increased neural activity in brain regions including the neocortex, caudoputamen, central amygdala, and parasubthalamic nucleus while decreasing activity in the hypothalamus, cortical amygdala, striatum, and pallidum. The effects of both the drug and the environment were strong and widespread but largely independent, with very few interactions between context and psilocybin treatment. This suggests that the brain's response to psilocybin is not strongly modulated by environmental setting at the level of immediate early gene expression.
Scientific reports
February 19, 2025
Xue Zhang, Xin Zhao, Jiaxin Xu et al.
8 citations
For emergency intubation in critically ill adults, using esketamine for induction results in higher mean arterial pressure during and after the procedure compared to a midazolam/sufentanil admixture, with no significant difference in heart rate. Patients receiving esketamine required less norepinephrine, had a shorter duration of ventilation support (median 105 vs. 212 hours), and a shorter ICU stay (median 7 vs. 15 days). 28-day mortality did not differ between groups, and no serious adverse events occurred. Esketamine appears to be a hemodynamically stable induction agent for this population.
BMC anesthesiology
May 31, 2024
Xin Luo, Wen-Wen Hao, Xue Zhang et al.
7 citations
Adding esketamine to propofol reduces the amount of propofol needed for successful ureteroscope insertion in elderly male patients compared with adding sufentanil. In a randomized trial of 49 elderly men undergoing rigid ureteroscopy, the median effective dose (ED50) of propofol was 1.356 mg/kg with esketamine versus 1.442 mg/kg with sufentanil, a statistically significant decrease. Induction time was also shorter with esketamine, and hemodynamic stability was better. Rates of adverse events such as hypoxemia and body movement did not differ between groups. The combination may improve safety by lowering propofol requirements in this older population.
bioRxiv Preprint Server
September 20, 2021
Laura M. Hack, Katherine G. Warthen, Xue Zhang et al.
2 citations
preprint
Ketamine, a drug used for depression and anesthesia, causes dose-dependent increases in dissociation and intoxication, reduces emotional insensitivity, and raises stress as measured by cortisol. It alters brain connectivity, particularly between reward and negative affect circuits and thalamic sub-regions. Increased coupling between the amygdala and anteroventral thalamus correlates with greater dissociation and intoxication, while decreased coupling of anteromedial and posterior parietal thalamus correlates with increased sensory reward responsiveness. Drug-altered connectivity involving the nucleus accumbens and thalamic sub-regions shows negative associations with anxiety. These findings help disentangle the brain states underlying ketamine's acute effects, informing its therapeutic use and abuse risk.
Proceedings of the National Academy of Sciences of the United States of America
June 16, 2026
Adam R Pines, Xue Zhang, John Kochalka et al.
Psychedelic drugs consistently reduce the strength and bottom-up direction of signal flow within the brain's default mode network, according to analyses of four independent datasets spanning humans and mice and three different psychedelic compounds (MDMA, psilocybin, and LSD). This attenuation of cortical propagations is not explained by data quality or previously known effects of psychedelics and is uniquely tied to self-reported outcomes. The findings clarify how psychedelics alter macroscale hierarchical processing in the brain.