European Archives of Psychiatry and Clinical Neuroscience
November 7, 2023
Ana-Maria Iorgu, Andrei-Nicolae Vasilescu, Natascha Pfeiffer et al.
2 citations
Psilocybin, unlike S-ketamine and MK-801, does not induce neuronal damage in the retrosplenial cortex of rats. Both S-ketamine and psilocybin are rapid-acting antidepressants that increase glutamate signalling and cortical hyperexcitation, but S-ketamine is known to cause neurotoxicity (Olney's lesions) in the retrosplenial cortex. Using immunohistochemical whole-brain mapping for heat shock protein 70 (HSP70) in rats, no HSP70-positive neurons were detected in the retrosplenial cortex of psilocybin-treated animals, whereas S-ketamine and MK-801 produced such markers. This suggests psilocybin may be safer for clinical use regarding neuronal damage.
Biomolecules
March 24, 2026
Veronica Begni, Floriana de Cillis, Natascha Pfeiffer et al.
Classical and rapid-acting antidepressants alter how the brain responds to acute stress through different molecular programs. In mice exposed to swim stress, imipramine dampened stress-induced neural activation in the cortex and striatum, while ketamine preserved it. Hippocampal activation remained robust and unaffected by either drug. BDNF expression changed only in the striatum, where imipramine reduced the stress-related increase. Both drugs similarly promoted active coping behaviors, but through distinct mechanisms. The findings suggest that cortical and striatal transcriptional signatures differentiate classical from rapid-acting antidepressant action, though human studies are needed to confirm clinical relevance.
European neuropsychopharmacology : the journal of the European College of Neuropsychopharmacology
October 1, 2015
Miriam A Vogt, Anne S Vogel, Natascha Pfeiffer et al.
Ketamine is a fast-acting antidepressant but can cause psychosis-like side effects. The nitric oxide donor sodium nitroprusside (SNP) prevents such effects in rats and humans. In mice, pre-treatment with SNP (0.5-1 mg/kg) did not alter the antidepressant effect of ketamine (30 mg/kg) in the Porsolt Forced Swim Test, and SNP alone had no effect. This suggests the nitrinergic system may be differentially involved in ketamine's antidepressant versus psychotomimetic effects, though species differences cannot be ruled out.