The findings that reduced GAD(67) mRNA expression can induce lower CB1R mRNA expression support the hypothesis that lower cortical levels of CB1Rs in schizophrenia may partially compensate for deficient GAD(67)-mediated GABA synthesis by reducing endogenous cannabinoid suppression of GABA release.
No study to-date has systematically investigated the impact of CNR1 on quantitative phenotypic features in schizophrenia and inter-relationships with marijuana misuse.
Our findings demonstrate that CB1 gene disruption dramatically alters the behavioural effects of the NMDA antagonist phencyclidine, suggesting that the CB1 receptor is involved in schizophrenia.
<b>Background:</b> Several studies have revealed significant associations between single nucleotide polymorphisms (SNPs) in the cannabinoid receptor 1 (<i>CNR1</i>) gene and a broad spectrum of psychiatric disorders such as major depressive disorder (MDD), attention deficit hyperactivity disorder (ADHD), and schizophrenia.
There is also tantalizing evidence from postmortem, neurochemical, and genetic studies suggesting CB1 receptor dysfunction (endogenous hypothesis) in schizophrenia that warrants further investigation.
However, further studies are necessary to unravel the relationship between mutations in the CNR1 gene and the genetic susceptibility for the manifestation of certain subtypes or schizophrenia i.e. the predominance of negative or positive symptoms or as predictors of the clinical course.
Cannabinoid receptor 1 (CNR1) gene polymorphisms have been associated with central and peripheral effects of cannabis and schizophrenia pathophysiology.
Papers were retrieved from PubMed and ISI Web of Knowledge using the search term schizophrenia in combination with CNR1 or CB1 or cannabinoid receptor.
In the present study, we investigated three polymorphisms (rs1049353, rs806368, and rs4707436) in the cannabinoid type 1 receptor gene (CNR1) and weight gain in Korean patients with schizophrenia receiving olanzapine treatment.
Recently, an (AAT)n triplet repeat polymorphism within the cannabinoid receptor gene CNR1 has been found to be associated with both schizophrenia and substance dependence, and to modulate the P300 potential.
We previously reported that marijuana misuse in conjunction with specific cannabinoid receptor 1 (CNR1) genetic variants (rs12720071-G-allele carriers) contributed to white-matter (WM) brain volume deficits in schizophrenia patients.
These results provide evidence that the prevalence of MetS is associated with the CNR1 gene in patients with SCZ during long-term treatment with antipsychotic treatment.
The G allele of the CNR1 gene polymorphisms could be a psychopharmacogenetic rather than a vulnerability factor regarding schizophrenia and its treatment.
To gain insight into this factor, we assessed the postnatal developmental trajectory of CB1R expression in the methylazoxymethanol (MAM) model of schizophrenia.
The present findings indicated that certain alleles or genotypes of the CNR1 gene may confer a susceptibility of schizophrenia, especially of the hebephrenic type.
The results point towards the hypothesis that increased CB1R levels could be a confounding effect of antipsychotic medication in schizophrenia that is circumveneted by high fat feeding.
In this study, although the result indicates that CNR1 and CNR2 variations are unlikely to influence schizophrenia susceptibility in a Korean population, the findings would provide meaningful information for further genetic studies.
Post hoc tests indicated that this main effect was due to patients with paranoid SCZ having 22% higher levels of CB(1)R binding compared with the control group.