In conclusion, our study does not provide evidence that the 5-HT1A gene plays either a major or a minor role in the genetic predisposition to schizophrenia, bipolar affective disorder, or Tourette's syndrome.
As disturbances of serotonin neurotransmission are implicated in alcohol abuse and aggression, we have examined in BDNF (+/-) mice alcohol drinking behavior, as well as central 5-hydroxytryptamine (5-HT)1A receptor function at the level of 5-HT1A receptor-G protein interaction.
Our study used in situ hybridization to quantify 5-HT(1A), 5-HT(1B), and 5-HT(2A) mRNA levels in the hippocampus (HC) and 5-HT(1A) and 5-HT(2A) mRNA levels in the dorsolateral prefrontal cortex (DLPFC) of subjects with a history of major depression disorder (MDD), bipolar disorder (BPD), schizophrenia, and a normal comparison group (15 subjects per group).
Genotyped and determined 5-HT(1A) binding potential (BP) by positron emission tomography (PET) using [carbonyl-C-11]-WAY-100635 in 28 medication-free MDD subjects during a current major depressive episode and 43 controls.
Higher 5-HT1A receptor binding potential during a major depressive episode predicts poor treatment response: preliminary data from a naturalistic study.
Antidepressant treatment response across 5-HT1A-1019C/G genotype groups showed no differences in either Major Depressive Episode or major depression between genotype groups, whereas stratification for the melancholic subtype of depression revealed a significantly worse treatment response as conferred by the -1019CC genotype (p=0.02).
The results suggest that the genetic polymorphism of the 5-HT1A receptor may play a role in alcohol dependence and polymorphisms of serotonergic genes may be important in withdrawal symptoms of patients with alcohol dependence.
Future studies should evaluate the role of genetic and environmental factors in producing elevated 5-HT(1A) BP(F) and MDD, and should examine whether 5-HT(1A) BP(F) is a vulnerability factor to MDEs that could have a role in screening high-risk populations for MDD.
Because 5-HT(1A) receptors have been implicated in the development of alcohol dependence, we have examined ethanol preference in PACAP-deficient mice using a two-bottle choice and a conditioned place preference test, as well as additive effects of ethanol and 5-HT(1A) receptor agents on hypothermia.
Due to its modulatory effect on serotonin (5-HT) release, the 5-HT(1A)-receptor is thought to play a decisive role in the therapy of this mood disorder.
This is the first study that associated 5-HT1A receptor promoter gene variants with stressors preceding the need of hospitalization for bipolar depression.
In the alcohol dependence with suicide group, anxiety symptoms were associated with decreased BA 24 SERT mRNA and depressive symptoms with BA 9 5HT1A mRNA expression.
Aberrant expression of the presynaptic serotonin 1A receptor (5-HT(1A)-R) because of a polymorphism in the 5-HT(1A)-R gene is associated with severe depression in human, whereas its absence up to postnatal day 21 (P21) in the forebrain of mice results in heightened anxiety in adulthood.
Results from this expanded meta-analysis, which included our own new study, suggest that rs6295 (C-1019G) and rs878567 in HTR1A are related to the pathophysiology of MDs, with overlap between MDD and BP.
To further explore the genetic components of MDD and utility of 5-HT(1A) imaging as a potential tool for biomarker or treatment response prediction, these findings should be replicated in a larger cohort using the [(11)C]CUMI-101 agonist tracer.
We identified a significant risk region for alcohol and nicotine codependence between IPO11 and HTR1A on chromosome 5q that was reported to be suggestively associated with alcohol dependence previously.
Results from this expanded meta-analysis, which included our own new study, suggest that rs6295 (C-1019G) and rs878567 in HTR1A are related to the pathophysiology of MDs, with overlap between MDD and BP.