Mice Lacking Serotonin Receptor Are Less Anxious
Fear- and depression-related behaviors unaffected
THURSDAY, July 27 (HealthDay News) -- Mice that lack receptors for serotonin are less anxious than wild-type mice when confronted with new and potentially threatening situations, with no effect on fear- and depression-related behaviors, researchers report in the July 28 issue of Science.
Jay A. Gingrich, M.D., Ph.D., from Columbia University in New York City, and colleagues created mice lacking the serotonin receptor 5-HT2A and studied its effects on anxiety-, fear- and depression-related behaviors.
The researchers found that the mice were less anxious when confronted with unfamiliar situations such as eating in a new environment or traveling through an open field, dark or brightly lit areas, or an elevated plus-maze. In contrast, fear- and depression-related behaviors were unaffected. The team was able to restore anxious behavior by restoring receptor function in the brain cortex but not the subcortical regions.
"These findings indicate a specific role for cortical 5-HT2A-receptor function in the modulation of conflict anxiety, consistent with models of cortical, 'top-down' influences on risk assessment," Gingrich and colleagues conclude.