Cookies on this website

We use cookies to ensure that we give you the best experience on our website. If you click 'Accept all cookies' we'll assume that you are happy to receive all cookies and you won't see this message again. If you click 'Reject all non-essential cookies' only necessary cookies providing core functionality such as security, network management, and accessibility will be enabled. Click 'Find out more' for information on how to change your cookie settings.

The long allele variant of the serotonin transporter (SERT, 5-HTT) gene-linked polymorphic region (5-HTTLPR) is associated with higher levels of 5-HTT expression and reduced risk of developing affective disorders. However, little is known about the mechanisms underlying this protective effect. One hypothesis is that 5-HTT expression influences aversive information processing, with reduced negative cognitive bias present in those with higher 5-HTT expression. Here we investigated this hypothesis using genetically-modified mice and a novel aversive learning paradigm. Mice with high levels of 5-HTT expression (5-HTT over-expressing, 5-HTTOE mice) and wild-type mice were trained to discriminate between three distinct auditory cues: one cue predicted footshock on all trials (CS+); a second cue predicted the absence of footshock (CS-); and a third cue predicted footshock on 20% of trials (CS20%), and was therefore ambiguous. Wild-type mice exhibited equivalently high levels of fear to the CS+ and CS20% and minimal fear to the CS-. In contrast, 5-HTTOE mice exhibited high levels of fear to the CS+ but minimal fear to the CS- and the CS20%. This selective reduction in fear to ambiguous aversive cues suggests that increased 5-HTT expression reduces negative cognitive bias for stimuli with uncertain outcomes.

Original publication

DOI

10.1111/gbb.12215

Type

Journal article

Journal

Genes Brain Behav

Publication Date

04/2015

Volume

14

Pages

330 - 336

Keywords

5-HTT, 5-HTTLPR, SERT, ambiguous, animal model, cognitive bias, fear, mice, over-expressing, serotonin transporter, Animals, Conditioning, Classical, Cues, Discrimination (Psychology), Fear, Female, Male, Mice, Mice, Inbred C57BL, Serotonin Plasma Membrane Transport Proteins