A functional promoter polymorphism in the serotonin receptor 1A (5-HT1A) gene has been found to be associated with major depression as well as anxiety- and depression-related personality traits.
In this study, we examined the serotonin 1A receptor gene, HTR1A, for its association with shared genetic risk across a range of anxiety and depression-related phenotypes.
We thus conducted a structural equation model (SEM) to examine whether the HTR1Ars6295 variant can affect anxiety by altering parasympathetic nervous activity.
There is a growing amount of evidence showing the importance of 5-HT1A in different psychiatric disorders, from mood to anxiety disorders, moving through suicidal behaviour and psychotic disorders.
In contrast, the GABA(A)-BZ receptor system seems to function normally in the 5-HT(1A) R KO in the 129/Sv background suggesting that changes in the GABA(A)-BZ receptor system may not be a prerequisite for anxiety but rather could have a modifying effect on this phenotype.
These results demonstrate that 5-HT1A receptors are involved in the modulation of exploratory and fear-related behaviors and suggest that reductions in 5-HT1A receptor density due to genetic defects or environmental stressors might result in heightened anxiety.