Display Settings:

Format

Send to:

Choose Destination
Psychopharmacology (Berl). 2010 Apr;209(2):163-74. doi: 10.1007/s00213-010-1784-0. Epub 2010 Feb 19.

The serotonin 2C receptor potently modulates the head-twitch response in mice induced by a phenethylamine hallucinogen.

Author information

  • 1Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, TN, 37232, USA. clinton.canal@ufl.edu

Abstract

RATIONALE:

Hallucinogenic serotonin 2A (5-HT(2A)) receptor partial agonists, such as (+ or -)-1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane hydrochloride (DOI), induce a frontal cortex-dependent head-twitch response (HTR) in rodents, a behavioral proxy of a hallucinogenic response that is blocked by 5-HT(2A) receptor antagonists. In addition to 5-HT(2A) receptors, DOI and most other serotonin-like hallucinogens have high affinity and potency as partial agonists at 5-HT(2C) receptors.

OBJECTIVES:

We tested for involvement of 5-HT(2C) receptors in the HTR induced by DOI.

RESULTS:

Comparison of 5-HT(2C) receptor knockout and wild-type littermates revealed an approximately 50% reduction in DOI-induced HTR in knockout mice. Also, pretreatment with either the 5-HT(2C) receptor antagonist SB206553 or SB242084 eradicated a twofold difference in DOI-induced HTR between the standard inbred mouse strains C57BL/6J and DBA/2J, and decreased the DOI-induced HTR by at least 50% in both strains. None of several measures of 5-HT(2A) receptors in frontal cortex explained the strain difference, including 5-HT(2A) receptor density, Galpha(q) or Galpha(i/o) protein levels, phospholipase C activity, or DOI-induced expression of Egr1 and Egr2. 5-HT(2C) receptor density in the brains of C57BL/6J and DBA/2J was also equivalent, suggesting that 5-HT(2C) receptor-mediated intracellular signaling or other physiological modulators of the HTR may explain the strain difference in response to DOI.

CONCLUSIONS:

We conclude that the HTR to DOI in mice is strongly modulated by 5-HT(2C) receptor activity. This novel finding invites reassessment of hallucinogenic mechanisms involving 5-HT(2) receptors.

PMID:
20165943
[PubMed - indexed for MEDLINE]
PMCID:
PMC2868321
Free PMC Article

Images from this publication.See all images (7)Free text

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6
Fig. 7

Publication Types, MeSH Terms, Substances, Grant Support

PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for Springer Icon for PubMed Central
    Loading ...
    Write to the Help Desk