GABA-A receptor differences in schizophrenia: a positron emission tomography study using [11C]Ro154513.
Mol Psychiatry
; 26(6): 2616-2625, 2021 06.
Article
em En
| MEDLINE
| ID: mdl-32296127
ABSTRACT
A loss of GABA signaling is a prevailing hypothesis for the pathogenesis of schizophrenia. Preclinical studies indicate that blockade of the α5 subtype of the GABA receptor (α5-GABAARs) leads to behavioral phenotypes associated with schizophrenia, and postmortem evidence indicates lower hippocampal α5-GABAARs protein and mRNA levels in schizophrenia. However, it is unclear if α5-GABAARs are altered in vivo or related to symptoms. We investigated α5-GABAARs availability in antipsychotic-free schizophrenia patients and antipsychotic-medicated schizophrenia patients using [11C]Ro15-4513 PET imaging in a cross-sectional, case-control study design. Thirty-one schizophrenia patients (n = 10 antipsychotic free) and twenty-nine matched healthy controls underwent a [11C]Ro15-4513 PET scan and MRI. The α5 subtype GABA-A receptor availability was indexed using [11C]Ro15-4513 PET imaging. Dynamic PET data were analyzed using the two-tissue compartment model with an arterial plasma input function and total volume of distribution (VT) as the outcome measure. Symptom severity was assessed using the PANSS scale. There was significantly lower [11C]Ro15-4513 VT in the hippocampus of antipsychotic-free patients, but not in medicated patients (p = 0.64), relative to healthy controls (p < 0.05; effect size = 1.4). There was also a significant positive correlation between [11C]Ro15-4513 VT and total PANSS score in antipsychotic-free patients (r = 0.72; p = 0.044). The results suggest that antipsychotic-free patients with schizophrenia have lower α5-GABAARs levels in the hippocampus, consistent with the hypothesis that GABA hypofunction underlies the pathophysiology of the disorder.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Esquizofrenia
/
Receptores de GABA-A
Tipo de estudo:
Observational_studies
/
Prevalence_studies
/
Prognostic_studies
/
Risk_factors_studies
Limite:
Humans
Idioma:
En
Revista:
Mol Psychiatry
Assunto da revista:
BIOLOGIA MOLECULAR
/
PSIQUIATRIA
Ano de publicação:
2021
Tipo de documento:
Article
País de afiliação:
Reino Unido