Psychedelics directly activate a small subset of serotonin 5-HT2A receptor-expressing excitatory neurons in the cortex, which then recruit inhibitory somatostatin and parvalbumin GABAergic interneurons, as well as astrocytes, producing distinct regional responses. This finding clarifies the cellular mechanisms underlying psychedelics' effects on perception and cognition, and their therapeutic potential for anxiety, depression, and addiction. The study also introduces a fluorescence-activated cell sorting (FACS) method for isolating specific brain cell subtypes based on cytoplasmic epitopes, enabling downstream nucleic acid analysis and expanding FACS applications in neuroscience.
Older adults with subjective cognitive decline who doubled their weekly calligraphy practice for six months showed increased functional connectivity in several default mode network regions compared with those who maintained their usual practice. The intervention group exhibited stronger connections between the medial prefrontal cortex and right lateral temporal cortex, medial prefrontal cortex and right inferior parietal lobe, left hippocampal formation and right lateral temporal cortex, and left hippocampal formation and right inferior parietal lobe. These positive neuromodulatory effects suggest that increasing engagement in cognitive activities in late life may support brain health.
Nitrous oxide, a gas that blocks the N-methyl-d-aspartate receptor, shows rapid but short-lived antidepressant effects in early-phase trials. Pooled results from three trials using a single 50% dose found significant reductions in depressive symptoms at 2 hours and 24 hours after inhalation, but not at one week. Side effects were mild and temporary, with the 25% dose being better tolerated. Most trials were small, early-phase studies focused on short-term outcomes in adults with major depressive disorder or treatment-resistant depression. Whether nitrous oxide will become a useful clinical treatment depends on whether its effects can be sustained through optimized or repeated dosing.