Halberstadt, AL, Luethi, D, Hoener, MC, Trachsel, D, Brandt, SD and Liechti, ME (2022) Use of the head-twitch response to investigate the structure-activity relationships of 4-thio-substituted 2,5-dimethoxyphenylalkylamines. Psychopharmacology. ISSN 0033-3158
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Use of the head-twitch response to investigate the structure-activity relationships of 4-thio-substituted 2,5-dimethoxyphenylalkylamines.pdf - Published Version Available under License Creative Commons Attribution. Download (1MB) | Preview |
Abstract
Rationale: 4-Thio-substituted phenylalkylamines such as 2,5-dimethoxy-4-ethylthiophenethylamine (2C-T-2) and 2,5-dimethoxy-4-n-propylthiophenethylamine (2C-T-7) produce psychedelic effects in humans and have been distributed as recreational drugs. Objectives: The present studies were conducted to examine the structure-activity relationships (SAR) of a series of 4-thio-substituted phenylalkylamines using the head twitch response (HTR), a 5-HT2A receptor-mediated behavior induced by psychedelic drugs in mice. The HTR is commonly used as a behavioral proxy in rodents for human psychedelic effects and can be used to discriminate hallucinogenic and non-hallucinogenic 5-HT2A agonists. Methods: HTR dose-response studies with twelve different 4-thio-substituted phenylalkylamines were conducted in male C57BL/6J mice. To detect the HTR, head movement was recorded electronically using a magnetometer coil and then head twitches were identified in the recordings using a validated method based on artificial intelligence. Results: 2C-T, the parent compound of this series, had relatively low potency in the HTR paradigm, but adding an α-methyl group increased potency fivefold. Potency was also increased when the 4-methylthio group was extended by one to three methylene units. Fluorination of the 4-position alkylthio chain, however, was detrimental for activity, as was the presence of a 4-allylthio substituent versus a propylthio group. 2C-T analogs containing a 4-benzylthio group showed little or no effect in the HTR paradigm, which is consistent with evidence that bulky 4-substituents can dampen agonist efficacy at the 5-HT2A receptor. Binding and functional studies confirmed that the compounds have nanomolar affinity for 5-HT2 receptor subtypes and act as partial agonists at 5-HT2A. Conclusions: In general, there were close parallels between the HTR data and the known SAR governing activity of phenylalkylamines at the 5-HT2A receptor. These findings further support the classification of 2C-T drugs as psychedelic drugs.
Item Type: | Article |
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Uncontrolled Keywords: | Psychiatry; 11 Medical and Health Sciences; 17 Psychology and Cognitive Sciences |
Subjects: | R Medicine > RM Therapeutics. Pharmacology |
Divisions: | Pharmacy & Biomolecular Sciences |
Publisher: | Springer Verlag |
SWORD Depositor: | A Symplectic |
Date Deposited: | 18 Nov 2022 10:52 |
Last Modified: | 16 Dec 2022 11:00 |
DOI or ID number: | 10.1007/s00213-022-06279-2 |
URI: | https://researchonline.ljmu.ac.uk/id/eprint/18166 |
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