Brain stimulation
January 1, 2024
Charles R Conway, Scott T Aaronson, Harold A Sackeim et al.
16 citations
Patients with treatment-resistant unipolar major depressive disorder who qualified for the RECOVER trial—the largest randomized sham-controlled study of vagus nerve stimulation for a psychiatric condition—had severe disability, a median of 11.0 prior failed antidepressant treatments, and high rates of suicidality (77% with suicidal ideation, 40% with previous suicide attempts). Seventy-one percent had received at least one prior interventional psychiatric treatment (electroconvulsive therapy, transcranial magnetic stimulation, or esketamine). Compared to those without such history, recipients of interventional treatments were younger, more severely depressed, had greater suicidal ideation, earlier onset of depression, and more failed medication trials.
Network neuroscience (Cambridge, Mass.)
January 1, 2026
Hiba Sheheitli, Robert Hermosillo, Gracie Grimsrud et al.
Metastability of BOLD fMRI signals, a proxy for brain dynamics, shows within-subject reliability comparable to static functional connectivity when enough data are used, but the amount needed varies across brain networks. Combining network-specific metastability metrics into a single feature vector improves reliability by an order of magnitude. This finding was reproduced in the Midnight Scan Club dataset (10 subjects over 10 days). The measure also proved sensitive to change in brain dynamics under psilocybin. The authors conclude the combined feature vector is a promising candidate for individual-specific biomarkers and precision neuromodulation targets.
Neuroscience
January 26, 2026
Batoul Darwish, Jad El Masri, Lina Hourieh et al.
Exposure to nitrous oxide gas reduced anxiety-related symptoms and enhanced hippocampal neurogenesis in male rats with PTSD-like behavior induced by the single prolonged stress (SPS) model. SPS-exposed rats showed reduced exploratory performance in the Y-maze test, increased anxiety behavior in the elevated plus maze, and decreased neurogenesis compared to sham controls. Nitrous oxide exposure counteracted these effects, aligning with prior research suggesting it as a promising therapeutic avenue for PTSD and other psychological disorders. The authors propose nitrous oxide as a therapeutic approach for treating cognitive and anxiety-related symptoms of PTSD through its effects on hippocampal neurogenesis, but note that further research is needed to understand potential benefits, risks, and long-term impacts.
Frontiers in cellular neuroscience
January 1, 2018
Farah Chamaa, Hisham F Bahmad, Ahmad-Kareem Makkawi et al.
Sub-anesthetic doses of nitrous oxide (N2O), an NMDA antagonist, increase hippocampal cell proliferation in adult male rats. Single exposure to 70% N2O with 30% oxygen led to a 1.4-fold increase in cell proliferation in the dentate gyrus after seven days compared to sham groups, while multiple exposures doubled the rate. Cell proliferation rates were comparable between N2O and sham groups at day one. The findings suggest that N2O, like ketamine, may ultimately enhance neurogenesis, pointing to potential antidepressant effects.