1. Effect of psilocybin on decision-making and motivation in the healthy rat.
- Author
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Roberts BF, Zylko AL, Waters CE, Crowder JD, Gibbons WJ Jr, Sen AK, Jones JA, and McMurray MS
- Subjects
- Rats, Male, Female, Animals, Motivation, Brain metabolism, Serotonin pharmacology, Receptors, Serotonin metabolism, Psilocybin pharmacology, Hallucinogens pharmacology
- Abstract
Psilocybin and its active metabolite psilocin are hallucinogenic serotonergic agonists with high affinity for several serotonin receptors. In addition to underlying the hallucinogenic effects of these compounds, serotonin receptor activation also has important effects on decision-making and goal-directed behaviors. The impact of psilocybin and psilocin on these cognitive systems, however, remains unclear. This study investigated the effects of psilocybin treatment on decision-making and motivation in healthy male and female rats. We compared probability and delay discounting performance of psilocybin treated (1 mg/kg) to vehicle rats (n = 10/sex/group), and further assessed motivation in each group using a progressive ratio task. We also confirmed drug action by assessing head twitch responses after psilocybin treatment (1 mg/kg). Results from this study demonstrated that exposure to 1 mg/kg psilocybin did not affect decision-making in the probability and delay discounting tasks and did not reduce response rates in the progressive ratio task. However, psilocybin treatment did cause the expected increase in head twitch responses in both male and female rats, demonstrating that the drug was delivered at a pharmacologically relevant dosage. Combined, these results suggest that psilocybin may not impair or improve decision-making and motivation. Considering recent interest in psilocybin as a potential fast-acting therapeutic for a variety of mental health disorders, our findings also suggest the therapeutic effects of this drug may not be mediated by changes to the brain systems underlying reward and decision-making. Finally, these results may have important implications regarding the relative safety of this compound, suggesting that widespread cognitive impairments may not be seen in subjects, even after chronic treatment., Competing Interests: Competing Interests JAJ, WJG, and MSM are co-inventors on several related patent applications. PsyBio Therapeutics has licensed psilocybin biosynthesis-related technology from Miami University and provided funding for this project. JAJ is the chairman of the scientific advisory board and a significant stakeholder at PsyBio Therapeutics. MSM is an unpaid member of the scientific advisory board at PsyBio Therapeutics. All other authors declare no conflicts of interest., (Copyright © 2022 Elsevier B.V. All rights reserved.)
- Published
- 2023
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