RESUMEN
There is strong evidence for the importance of the serotonin (5-HT) system in the neurobiology of panic disorder (PD); however, the exact role of this system remains unclear. The 5-HT transporter (5-HTT) is a key element in 5-HT neurotransmission. The current study aimed to investigate the binding of 5-HTT in the brain of patients with PD. We used single-photon emission computed tomography with a radioligand that specifically labels the 5-HTT, [(123)I]nor-beta-CIT. Subjects comprised eight patients with current PD, eight patients with PD in remission, and eight healthy control subjects. The patients with current PD showed a significant decrease in 5-HTT binding in the midbrain, in the temporal lobes and in the thalamus in comparison to the controls. The binding of 5-HTT in patients with PD in remission was similar to findings in the control group in the midbrain and in the temporal lobes, but lower in the thalamus. Regional 5-HTT binding significantly and negatively correlated with the severity of panic symptoms. These findings point to a dysregulation of the 5-HT system in PD patients. Altered function of 5-HTT appears to be related to the clinical status of patients. Clinical improvement in the patients in remission is associated with normalization of 5-HTT binding.
Asunto(s)
Sitios de Unión/fisiología , Encéfalo/irrigación sanguínea , Encéfalo/metabolismo , Trastorno de Pánico/metabolismo , Serotonina/metabolismo , Tomografía Computarizada de Emisión de Fotón Único , Adulto , Femenino , Humanos , Masculino , Mesencéfalo/irrigación sanguínea , Mesencéfalo/metabolismo , Pruebas Neuropsicológicas , Trastorno de Pánico/diagnóstico , Índice de Severidad de la Enfermedad , Lóbulo Temporal/irrigación sanguínea , Lóbulo Temporal/metabolismo , Tálamo/irrigación sanguínea , Tálamo/metabolismoRESUMEN
The purpose of this study was to characterize the binding properties of serotonin transporter (5-HTT) in the brain of the patients with generalized anxiety disorder (GAD) in comparison to healthy subjects using single photon emission computer tomography (SPECT) with the radioligand [123I]nor-beta-CIT. The subjects were 7 patients with GAD and 7 matched healthy volunteers. The regions of interest (ROI) were the midbrain and the thalamus. The comparison of the volumes of distribution did not show significant differences between the patients and controls in the binding of nor-beta-CIT to 5-HTT in the ROI. Binding of 5-HTT in the midbrain of patients was significantly and negatively correlated with their anxiety levels measured by the visual analogue scale immediately before the first scan (r=-0.79, p=0.035). This study failed to demonstrate an altered functional activity of 5-HTT in patients with GAD when compared with controls.