Frontiers in Neuroscience
May 1, 2025
Evan Fuini, Arnold Chang, Josh Edwards et al.
6 citations
Psilocybin, a hallucinogen, produces dose-dependent increases in brain activity in awake rats, particularly in the somatosensory cortex, basal ganglia, and thalamus. Female rats showed greater activation than males at the 0.3 mg/kg dose in thalamic and basal ganglia regions. The drug also caused a global increase in functional connectivity, especially hyperconnectivity to the cerebellum. Higher doses activated circuits involved in sensory filtering and motor organization, such as the cortico-striato-thalamo-cortical circuit and claustrum. However, the direction of BOLD signal changes and neural network activity patterns differed from those reported in human studies.
Neuropsychopharmacology
February 18, 2026
Itishree Sahoo, Sairam Masadi, Ashwath Maheswari et al.
3 citations
Adolescent mice given psilocybin every other day from postnatal days 40-50 showed long-term changes in brain structure and function when tested in adulthood. Brain imaging revealed reduced volume and altered water diffusivity in several regions, with males more affected than females. Functional connectivity increased globally and regionally, notably between the prefrontal cortex and hypothalamus, thalamus, and midbrain. Mice showed reduced brain sensitivity to rewarding and aversive odors, and males had lower levels of epigenetic and neuroplasticity protein markers in the prefrontal cortex. Behaviorally, female mice showed reduced mobility in the open field test, while no differences appeared in the light/dark box test. These findings indicate that adolescent psilocybin exposure produces lasting developmental consequences, especially in males.
Neuropharmacology
March 6, 2026
Noah Cavallaro, Priya Rai, David Akins et al.
1 citation
In a first-ever fMRI study of 5-MeO-DMT, a fast-acting psychedelic, brain activity changes were observed that match its quick onset and short peak effects. A previously unknown sex difference in how the brain responds to the drug was also identified. The findings align with the drug's unique pharmacology and clinical reports, offering new insights into its neural effects.
Neuroscience bulletin
May 21, 2026
Noah Cavallaro, Priya Rai, David Akins et al.
Mescaline, a psychedelic used ceremonially for thousands of years, produces distinct brain effects that differ from LSD and psilocybin. In awake rats, mescaline suppressed BOLD signal in the cerebellum, suggesting it disconnects this region from forebrain areas. However, resting-state scans showed the cerebellum became hyperconnected to the hippocampus, thalamus, somatosensory cortex, and midbrain. Mescaline also eliminated normal brain responses to rewarding smells, indicating disrupted sensory processing. Acoustic startle tests revealed frequency-dependent effects: enhancement at 4 kHz (+27.6%) and 20 kHz (+27.3%), but impairment at 12 kHz (-16.4%). The cerebellum may act as a dysregulated sensory filter, flooding forebrain circuits with unprocessed information, potentially explaining psychedelic-induced perceptual changes.