Display Settings:

Format

Send to:

Choose Destination
See comment in PubMed Commons below
Neuropharmacology. 2013 Jan;64:403-13. doi: 10.1016/j.neuropharm.2012.06.007. Epub 2012 Jun 18.

Stimulation of serotonin 2A receptors facilitates consolidation and extinction of fear memory in C57BL/6J mice.

Author information

  • 1Department of Psychology, BS101, Charles E. Schmidt College of Science, Florida Atlantic University, 777 Glades Road, Boca Raton, FL 33431-0991, USA. gzhang@fau.edu

Abstract

Excessive fear is a hallmark of several emotional and mental disorders such as phobias and panic disorders. Considerable attention is focused on defining the neurobiological mechanisms of the extinction of conditioned fear memory in an effort to identify mechanisms that may hold clinical significance for remediating aberrant fear memory. Serotonin modulates the acquisition and retention of conditioned emotional memory, and the serotonin 2A receptor (5HT2AR) may be one of the postsynaptic targets mediating such effects. Here we tested the hypothesis that the 5HT2AR regulates the consolidation and extinction of fear memory in male C57BL/6J mice. The influence of 5HT2ARs on memory consolidation was further confirmed with a novel object recognition task. With a trace fear conditioning paradigm, administration of the 5HT2AR agonist TCB-2 (1.0 mg/kg, i.p.) before the extinction test facilitated the acquisition of extinction of fear memory as compared to vehicle treatment. In contrast, administration of the 5HT2AR antagonist MDL 11,939 (0.5 mg/kg, i.p.) delayed the acquisition of extinction of fear memory. Further, the post-conditioning administration of TCB-2 enhanced contextual and cued fear memory, possibly by facilitating the consolidation of fear memory. Administration of TCB-2 also facilitated the acquisition of extinction of fear memory in delay fear conditioned mice. Stimulation or blockade of 5HT2ARs did not affect the encoding or retrieval of conditioned fear memory. Finally, administration of TCB-2 right after training in an object recognition task enhanced the consolidation of object memory. These results suggest that stimulation of 5HT2ARs facilitates the consolidation and extinction of trace and delay cued fear memory and the consolidation of object memory. Blocking the 5HT2AR impairs the acquisition of fear memory extinction. The results support the view that serotonergic activation of the 5HT2AR provides an important modulatory influence on circuits engaged during extinction learning. Taken together these results suggest that the 5HT2AR may be a potential therapeutic target for enhancing hippocampal and amygdala-dependent memory. This article is part of a Special Issue entitled 'Cognitive Enhancers'.

Copyright © 2012 Elsevier Ltd. All rights reserved.

PMID:
22722027
[PubMed - indexed for MEDLINE]
PMCID:
PMC3477617
Free PMC Article

Images from this publication.See all images (6)Free text

Figure 1
Figure 2
Figure 3
Figure 4
Figure 5
Figure 6

Publication Types, MeSH Terms, Substances, Grant Support

PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Icon for Elsevier Science Icon for PubMed Central
    Loading ...
    Write to the Help Desk