A newly designed compound, (+)-JRT, structurally similar to LSD but with reduced hallucinogenic effects, promotes the growth of dendritic spines in the cortex—a process that is diminished in neuropsychiatric diseases such as depression, addiction, and schizophrenia. In behavioral tests, (+)-JRT showed antidepressant-like and cognition-enhancing effects without worsening signs related to psychosis. This suggests that nonhallucinogenic compounds that promote neuroplasticity could be safer alternatives to psychedelics for treating conditions where psychedelics pose risks.
A new compound called zalsupindole, designed to promote brain cell regrowth without causing hallucinations or dissociation, shows promise for treating depression. In rats, it produced robust structural and functional neuroplasticity in the prefrontal cortex and sustained antidepressant-like effects, comparable to or greater than ketamine, psilocybin, and DMT. Unlike these other compounds, zalsupindole lacked hallucinogenic or dissociative properties, suggesting it could be a safer and more scalable treatment for depression. This work addresses the need for neuroplastogens that promote cortical neuron regrowth without the safety concerns of psychedelics and dissociative anesthetics.
Tropane-containing small molecules such as scopolamine can promote neuronal growth (psychoplastogens) but also block all muscarinic receptor subtypes, causing unwanted anticholinergic side effects. Researchers conducted phenotypic structure-activity relationship studies on various tropane subclasses to separate these effects. They identified several novel tropanes that substantially increase cortical neuron growth while showing much weaker activity at all muscarinic receptor subtypes than scopolamine, suggesting that the neuroplasticity-promoting and muscarinic-blocking properties can be decoupled.
Nonhallucinogenic psychoplastogens like tabernanthalog (TBG) promote cortical neuroplasticity through the same biochemical pathway as classic psychedelics—involving 5-HT2A, TrkB, mTOR, and AMPA receptor activation—but without inducing an immediate glutamate burst or immediate early gene activation. TBG-induced cortical spinogenesis is required for its sustained antidepressant-like behavioral effect in rodents. These findings clarify how certain psychoplastogens can produce neuroplasticity without hallucinogenic effects, challenging assumptions that glutamate burst and IEG activation are necessary for psychedelic-induced neuroplasticity.