LSD activates the TrkB signaling pathway in human neural stem cells (NSCs) similarly to the growth factor BDNF, but unlike BDNF, LSD does not promote NSC proliferation. This suggests LSD may activate an alternative mechanism that counteracts BDNF-TrkB signaling in NSCs, revealing a previously unrecognized cell type-specificity of LSD. The finding may deepen understanding of how LSD produces fast and persistent effects on anxiety and depression.
Daily injections of phencyclidine (PCP) at 3.0 mg/kg or ketamine at 0.8 mg/kg in two macaque monkeys produced robust reductions in accuracy and increases in reaction time during high cognitive-demanding tasks. Saccades, smooth pursuit, and fixation stability were significantly impaired; involuntary microsaccades during fixation increased in amplitude and were biased toward the lower visual field. Pupillary response during cognitive tasks was reduced, and sensitivity to auditory cues increased as shown by auditory evoked potentials. A machine-learning classifier identified altered states induced by different drugs with 93% accuracy, and 90% accuracy when data from one monkey trained and tested the other, demonstrating data transferability across individuals.