Depressive DisordersKetamineLSD

Transient Stimulation with Psychoplastogens Is Sufficient to Initiate Neuronal Growth

This in vitro study demonstrated that the psychoplastogens ketamine and LSD promote sustained cortical neuron growth, a process hypothesized to reverse atrophy associated with depression. The study finds that this growth occurs via two distinct phases involving initial TrkB activation followed by sustained mTOR and AMPA receptor activation.

Authors

  • Maxemiliano Vargas

Published

ACS Pharmacology and Translational Science
individual Study

Abstract

Cortical neuron atrophy is a hallmark of depression and includes neurite retraction, dendritic spine loss, and decreased synaptic density. Psychoplastogens, small molecules capable of rapidly promoting cortical neuron growth, have been hypothesized to produce long-lasting positive effects on behavior by rectifying these deleterious structural and functional changes. Here we demonstrate that ketamine and LSD, psychoplastogens from two structurally distinct chemical classes, promote sustained growth of cortical neurons after only short periods of stimulation. Furthermore, we show that psychoplastogen-induced cortical neuron growth can be divided into two distinct epochs: an initial stimulation phase requiring TrkB activation and a growth period involving sustained mTOR and AMPA receptor activation. Our results provide important temporal details concerning the molecular mechanisms by which next-generation antidepressants produce persistent changes in cortical neuron structure, and they suggest that rapidly excreted psychoplastogens might still be effective neurotherapeutics with unique advantages over compounds like ketamine and LSD.

Available with Blossom Pro

Research Summary of 'Transient Stimulation with Psychoplastogens Is Sufficient to Initiate Neuronal Growth'

Introduction

Depression is associated with structural degeneration in prefrontal cortical circuits, including dendritic retraction, loss of dendritic spines, and reduced excitatory synapse density. Conventional antidepressants (for example selective serotonin reuptake inhibitors) require chronic dosing and have limited efficacy for many patients, prompting interest in agents that rapidly promote neural plasticity. Psychoplastogens—small molecules such as ketamine, scopolamine and serotonergic psychedelics—can rapidly stimulate regrowth of cortical dendritic arbors and produce relatively long-lasting behavioural effects after single administrations, but the biochemical sequence that allows a short pharmacological exposure to yield sustained structural change is not well defined. Ly and colleagues set out to determine whether very brief exposures to psychoplastogens are sufficient to initiate sustained growth of cortical neurons and to dissect the temporal requirements for key signalling nodes. Using ketamine and lysergic acid diethylamide (LSD) as representative psychoplastogens, the study tests how short stimulation periods (minutes to hours) affect dendritogenesis, spinogenesis and synaptogenesis in primary cortical cultures, and uses pharmacological inhibitors to probe roles for TrkB, AMPA receptors and mTOR during both the initial stimulation and the subsequent drug-free growth phase. The work aims to clarify mechanistic epochs underlying psychoplastogen-driven plasticity and to inform development of neurotherapeutics with rapid onset and reduced side effects.

Expert Research Summaries

Go Pro to access AI-powered section-by-section summaries, editorial takes, and the full research toolkit.

Study Details

References (20)

Papers cited by this study that are also in Blossom

Antidepressant effects of ketamine in depressed patients

Berman, R. M., Cappiello, A., Anand, A. et al. · Biological Psychiatry (2000)

Replication of Ketamine’s Antidepressant Efficacy in Bipolar Depression: A Randomized Controlled Add-On Trial

Zarate, C. A., Brutsche, N. E., Ibrahim, L. et al. · Biological Psychiatry (2012)

757 cited
The therapeutic potential of psychedelic drugs: past, present, and future

Carhart-Harris, R. L., Goodwin, G. M. · Neuropsychopharmacology (2017)

Psychedelics as Medicines: An Emerging New Paradigm

Nichols, C. D., Nichols, D. E., Johnson, M. W. · Clinical Pharmacology and Therapeutics (2016)

Antidepressant effects of a single dose of ayahuasca in patients with recurrent depression a SPECT study

Sanches, R. F., Osório, F. L., Dos Santos, R. G. et al. · Journal of Clinical Psychopharmacology (2016)

380 cited
Antidepressant effects of a single dose of ayahuasca in patients with recurrent depression: a preliminary report

Osório, F. L., Sanches, R. F., Macedo, L. et al. · brazilian Journal of Psychiatry (2015)

420 cited
Psilocybin with psychological support for treatment-resistant depression: an open-label feasibility study

Carhart-Harris, R. L., Bolstridge, M., Rucker, J. et al. · Lancet Psychiatry (2016)

1174 cited
Psilocybin for treatment-resistant depression: fMRI-measured brain mechanisms

Carhart-Harris, R. L., Roseman, L., Bolstridge, M. et al. · Scientific Reports (2017)

Show all 20 references
Psychedelics in the treatment of unipolar mood disorders: a systematic review

Rucker, J., Young, A. H., Jelen, L. A. et al. · Journal of Psychopharmacology (2016)

Psychedelics promote structural and functional neural plasticity

Ly, C., Greb, A. C., Cameron, L. P. et al. · Cell Reports (2018)

Psilocybin with psychological support for treatment-resistant depression: six-month follow-up

Carhart-Harris, R. L., Bolstridge, &. M., Day, C. M. J. et al. · Psychopharmacology (2017)

Rapid and Longer-Term Antidepressant Effects of Repeated Ketamine Infusions in Treatment-Resistant Major Depression

Murrough, J. W., Perez, A. M., Pillemer, S. et al. · Biological Psychiatry (2012)

Emotions and brain function are altered up to one month after a single high dose of psilocybin

Barrett, F. S., Doss, M. K., Sepeda, N. D. et al. · Scientific Reports (2020)

Long-term effects of psychedelic drugs: A systematic review

Aday, J. S., Mitzkovitz, C. M., Bloesch, E. K. et al. · Neuroscience and Biobehavioral Reviews (2020)

Pharmacokinetics and concentration-effect relationship of oral LSD in humans

Dolder, P. C., Schmid, Y., Haschke, M. et al. · International Journal of Neuropsychopharmacology (2015)

97 cited
Dark Classics in Chemical Neuroscience: N, N-Dimethyltryptamine (DMT)

Cameron, L. P. · ACS Chemical Neuroscience (2018)

Psychedelic Psychiatry’s Brave New World

Nutt, D. J., Erritzoe, D., Carhart-Harris, R. L. · Cell (2020)

Cited By (29)

Papers in Blossom that reference this study

1 cited
The psychoplastogen tabernanthalog induces neuroplasticity without proximate immediate early gene activation

Aarrestad, I. K., Cameron, L. P., Fenton, E. M. et al. · Nature Neuroscience (2025)

Meta-correlation of the effect of ketamine and psilocybin induced subjective effects on therapeutic outcome

Dahan, J. D. C., Dadiomov, D., Bostoen, T. et al. · npj Mental Health Research (2024)

Clinically relevant acute subjective effects of psychedelics beyond mystical experience

Yaden, D. B., Goldy, S. P., Weiss, B. et al. · Nature Reviews Psychology (2024)

Mind over matter: the microbial mindscapes of psychedelics and the gut-brain axis

Caspani, G., Ruffell, S. G. D., Tsang, WF. et al. · Pharmacological Research (2024)

Show all 29 papers
Neural complexity is increased after low doses of LSD, but not moderate to high doses of oral THC or methamphetamine

Murray, C., Frohlich, J, Haggarty, C. J., Tare, I. et al. · Neuropsychopharmacology (2024)

Psychedelics for acquired brain injury: a review of molecular mechanisms and therapeutic potential

Allen, J., Dames, S., Foldi, C. J. et al. · Molecular Psychiatry (2024)

Cortical structural differences following repeated ayahuasca use hold molecular signatures

Mallaroni, P., Mason, N. L., Kloft, L. et al. · Frontiers in Neuroscience (2023)

6 cited
Therapeutic mechanisms of psychedelics and entactogens

Heifets, B. D., Olson, D. E. · Neuropsychopharmacology (2023)

Sub-acute effects of psilocybin on EEG correlates of neural plasticity in major depression: Relationship to symptoms

Skosnik, P. D., Sloshower, J., Safi-Aghdam, H. et al. · Journal of Psychopharmacology (2023)

Psychedelics promote plasticity by directly binding to BDNF receptor TrkB

Moliner, R., Girych, M., Brunello, C. A. et al. · Nature Neuroscience (2023)

A non-hallucinogenic LSD analog with therapeutic potential for mood disorders

Lewis, V., Bonniwell, E. M., Lanham, J. K. et al. · Cell Reports (2023)

102 cited
5-HT2ARs Mediate Therapeutic Behavioral Effects of Psychedelic Tryptamines

Cameron, L. P., Patel, S. D., Vargas, M. V. et al. · ACS Chemical Neuroscience (2023)

86 cited
The neural basis of psychedelic action

Kwan, A. C., Olson, D. E., Preller, K. H. et al. · Nature Medicine (2022)

Towards an understanding of psychedelic-induced neuroplasticity

Calder, A. E., Hasler, G. · Neuropsychopharmacology (2022)

Psychedelic Therapy's Transdiagnostic Effects: A Research Domain Criteria (RDoC) Perspective

Dursun, S. M., Kelly, J. R., Gillan, C. M. et al. · Frontiers in Psychiatry (2021)

Psychedelic-Inspired Approaches for Treating Neurodegenerative Disorders

Olson, D. E. · Journal of Neurochemistry (2021)

Serotonergic Psychedelics in Neural Plasticity

Torregrossa, M. M., Lu, J., Lukasiewicz, K. et al. · Frontiers in Molecular Neuroscience (2021)

Improving cognitive functioning in major depressive disorder with psychedelics: a dimensional approach

Kuiperes, Z., Schreiber, R. · Neurobiology of Learning and Memory (2021)

Psychedelic perceptions: mental health service user attitudes to psilocybin therapy

Corrigan, K., Haran, M., Mccandliss, C. et al. · Irish Journal of Medical Science (2021)

The Promise of Psychedelic Science

Olson, D. E. · ACS Pharmacology and Translational Science (2021)

Your Personal Research Library

Go Pro to save papers, add notes, rate studies, and organize your research into custom shelves.