Involvement of 5-HT1A receptors in animal tests of anxiety and depression: evidence from genetic models

Clinical studies have suggested the involvement of 5-HT1A receptors in anxiety and depressive disorders because partial 5-HT1A receptor agonists such as buspirone are therapeutic. The present review considers evidence from genetic animal models that support a role for 5-HT1A receptors in anxiety-like and depressed-like behavior in animals. Selective breeding for differential hypothermic responses to a selective 5-HT1A receptor agonist led to the development of the high DPAT sensitive (HDS) and low DPAT sensitive (LDS) lines of rats. The HDS rats differ from the LDS rats on several behavioral measures reflective of anxiety or depression, including reduced social interaction, reduced responding in a conflict task and exaggerated immobility in the forced swim test. However, they do not differ from the LDS rats in the elevated plus maze task, which is a commonly used test of anxiety. Nor do the HDS rats exhibit a typical anxiogenic response to the hippocampal administration of the 5-HT1A agonist. Although the HDS rats do exhibit elevations in 5-HT1A receptors in regions of the limbic cortex, it is not clear whether these increases account for the behavioral differences. Paradoxically, 5-HT1A receptor knockout mice also exhibit anxiety-like behavior in the plus maze, open field and conflict tests compared to wild type mice. However, the knockouts exhibited less immobility in the forced swim test than wild type control mice. Recent studies using selective regional reinstatement of the receptor have implicated the postsynaptic 5-HT1A receptors in these changes in anxiety-like behavior. Thus, preliminary evidence from two different types of genetic animal models suggests that anxiety-like behavior can arise if the 5-HT1A receptor function is eliminated or overexpressed. Further study with additional tests of anxiety are needed to confirm this intriguing relationship.     

Why are attributions to discrimination interpersonally costly? A test of system- and group-justifying motivations

In two studies, Whites' endorsement of system-justifying beliefs predicted increased negativity toward Blacks who blamed negative events on discrimination. Whites' system-justifying beliefs were not associated with negativity toward Blacks who blamed negative events on other internal causes, external causes, or nondiscriminatory unfairness. These negative reactions toward discrimination claimants were mediated by perceptions that the claimant held dissimilar values and failed to take personal responsibility for outcomes. In both studies, participants' White Identification did not moderate the relationship between the Black target's attribution for failure and subsequent negative perceptions of that individual, thus providing evidence against a group-justification explanation of these findings.     

Erratum to: Automatic change detection in vision: Adaptation,memory mismatch,or both? II: Oddball and adaptation effects on event-related potentials

Attention, Perception, & Psychophysics -