The serotonin 1B receptor is required for some of the behavioral effects of psilocybin in mice.
Sixtine Fleury, Katherine M. Nautiyal
Molecular Psychiatry May 1, 2026 DOI: 10.1038/s41380-025-03387-1 (opens in new tab)
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Study at a glance
AI-extracted from the abstract| Characteristics | Experimental study Peer reviewed |
|---|---|
| Population | Mice |
| Intervention | Psilocybin |
| Topics | Psilocybin Serotonin |
| Citations | 4 |
| Key findings | The serotonin 1B receptor influences brain-wide neural changes following psilocybin administration and may contribute to its enduring antidepressant-like effects in mice. |
Abstract
Recent studies highlight the promising use of psychedelic therapies for psychiatric disorders, including depression. The persisting clinical effects of psychedelics such as psilocybin are commonly attributed to activation of the serotonin 2A receptor (5-HT2AR) based on its role in the acute hallucinatory effects. However, the active metabolite of psilocybin binds to many serotonin receptor subtypes, including the serotonin 1B receptor (5-HT1BR). Given the known role of 5-HT1BR in mediating depressive phenotypes and promoting neural plasticity, we hypothesized that it mediates the effects of psilocybin on neural activity and behavior. We first examined the acute neural response to psilocybin in mice lacking 5-HT1BR. We found that 5-HT1BR expression influenced brain-wide activity following psilocybin administration, measured by differences in the patterns of the immediate early gene c-Fos, across regions involved in emotional processing and cognitive function, including the amygdala and other subcortical limbic structures. Functionally, we demonstrated that 5-HT1BR mediates some of the acute and persisting behavioral effects of psilocybin. Although there was no effect of 5-HT1BR expression on the acute head twitch response, mice lacking 5-HT1BRs had attenuated hypolocomotion to psilocybin. We also measured the persisting effects of psilocybin on anhedonia and anxiety-like behavior using transgenic and pharmacological 5-HT1BR loss-of-function models. Although there were effects of sex and stress paradigms, we found that 5-HT1B is involved in mediating some of the longer-lasting behavioral responses to psilocybin. Finally, using a network analysis, we identified neural circuits through which 5-H1BR may modulate the response to psilocybin. Our findings suggest that the 5-HT1BR influences brain-wide neural changes following psilocybin administration and may contribute to its enduring antidepressant-like effects in mice.
Comparable studies
Other preclinical and animal studies on serotonin, most cited first.
| Study | Year | Design | Participants |
|---|---|---|---|
| Psilocybin induces rapid and persistent growth of dendritic spines in frontal cortex in vivo Mice | 2021 | Observational cohort | |
| Neurotoxicity of the psychedelic amphetamine, methylenedioxymethamphetamine. Rats (implied by typical neurochemical study context) | 1987 | Experimental study | |
| Psychedelics promote neuroplasticity through the activation of intracellular 5-HT2A receptors In vitro and in vivo (rodent) models | 2023 | Experimental study | |
| 3,4-Methylenedioxymethamphetamine and 3,4-methylenedioxyamphetamine destroy serotonin terminals in rat brain: quantification of neurodegeneration by measurement of [3H]paroxetine-labeled serotonin uptake sites. Rat brain | 1987 | Animal experiment | |
| Comparison of the monoamine transporters from human and mouse in their sensitivities to psychostimulant drugs Human and mouse dopamine, norepinephrine, and serotonin transporters expressed in cells | 2006 | In vitro laboratory study |
Citations in the library
Cited by 5
- The serotonin 1B receptor as a target for the treatment of depression and anxiety Expert Opinion on Therapeutic Targets September 21, 2026
- Multilevel Mechanisms and Clinical Efficacy of Psilocybin in Depression Treatment: A Systematic Review International Journal of Molecular Sciences September 10, 2026
- Current status and future prospects of research on psilocybin's regulation of neurotransmitters and their receptors related to the pathogenesis of tinnitus. Hearing research August 1, 2026
- Convergent increases in serotonin 1B receptor binding following ketamine and electroconvulsive therapy: a multi-centre bayesian re-analysis of PET data Molecular Psychiatry July 8, 2026
- Serotonin 1B receptors expressed on forebrain excitatory neurons mediate the post-acute anxiolytic response to psilocybin in mice. Psychopharmacology October 17, 2026
Cites 45
- Psilocybin produces substantial and sustained decreases in depression and anxiety in patients with life-threatening cancer: A randomized double-blind trial Journal of Psychopharmacology November 30, 2016
- Psilocybin with psychological support for treatment-resistant depression: an open-label feasibility study. The Lancet Psychiatry May 17, 2016
- Trial of Psilocybin versus Escitalopram for Depression New England Journal of Medicine April 14, 2021
- Effects of Psilocybin-Assisted Therapy on Major Depressive Disorder JAMA Psychiatry November 4, 2020
- Psychedelics Promote Structural and Functional Neural Plasticity Cell Reports June 1, 2018
and 40 more in the library