Brain communications
January 1, 2024
Ashley Ghaw, Alisha Chunduri, Arnold Chang et al.
13 citations
Lysergic acid diethylamide (LSD) produced a dose-dependent increase in negative blood oxygen level-dependent (BOLD) signal, indicating decreased brain activity, in awake rats. The most affected regions were the primary olfactory system, prefrontal cortex, thalamus, and hippocampus. Contrary to the hypothesis that LSD would increase activity in the prefrontal cortex and thalamus while decreasing hippocampal activity, the results showed an acute decrease in activity across these areas. However, functional connectivity increased between the thalamus and somatosensory cortex, and between the cerebellar nuclei and surrounding brainstem areas. The enhanced thalamus-sensorimotor connectivity aligns with human studies, while the unexpected increase in cerebellar nuclei connectivity raises questions about its role in hallucinogenic effects.
Scientific reports
August 11, 2024
Lila Harris-Blum, Zachary Smith, Richard J Ortiz et al.
9 citations
Exposure to LSD during periadolescence in mice altered gray matter microarchitecture across much of the brain, particularly in the thalamus, sensory and motor cortices, and basal ganglia, while the forebrain olfactory system, prefrontal cortex, and hindbrain were unaffected. Multiple doses reduced functional connectivity between forebrain white matter tracts and sensorimotor cortices and hippocampus. However, no differences in brain volume, cognitive performance, or motor behavior were observed when the animals were tested as young adults. The pronounced changes in diffusion-weighted imaging values across 74 brain areas suggest altered neuroplasticity, but the behavioral consequences of the connectivity changes remain unknown.
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.