Determinación de Receptores 5HT1A y D2 de la Corteza Orbitofrontal y el Núcleo Accumbens Posterior a la Lesión del Núcleo Reticular del Tálamo, en el Modelo de Conducta Perseverante Inducido con 8-OH-DPAT en la Rata

Abstract

Obsessive-compulsive disorder (OCD) is a psychiatric illness that can lead to chronic functional impairment. Some patients with severe, chronic OCD have been treated with ablative neurosurgical techniques and recently, deep brain stimulation (DBS) has been investigated as a therapy for refractory OCD. However, is uncertain the neurobiochemistry mechanisms by which it operates. The aim of this study was to determine the thalamic-orbitofrontal system receptor dynamic after bilateral lesion of reticular thalamic nuclei. Material and Methods. Through [3H]-ligand binding assay were quantified the serotonin (5HT1A) and dopamine receptor (D2) of the orbitofrontal cortex (OFC) and nucleus accumbens (NAc), subsequent of thalamic reticular nucleus lesion, on a behavior induced persistent 8-OHDPAT model in rat. Results. The binding [3H]-8OH-DPAT in the NAc decreased, according to the left and right hemispheres, in the sham group (132.47, 101.60 fmol / mg, SD 40.56, 39.77, p = 0.024, p = 0.006), RTN lesion (137.83, 114.04 fmol / mg, SD 28.52, 25.14, p = 0.039, p = 0.006) compared with control (139.99 170.06, 149.99 fmol / mg, SD 33.83, 43.39), while there is similarity between the control, 8 -OH-DPAT (142.67, 138.93 fmol / mg, SD 27.62, 33.64) and the group RTN lesion + 8-OH-DPAT (189.08, 139.99 fmol / mg, SD 39.50, 18.15, p = 0.24, p = 0.55). The event was repeated only in the left OFC, sham (264 fmol / mg, DE 63.80, p = 0.001) NLRA (227 667 fmol / mg, DE 25.10, p = 0.0005) and RTN lesion + 8-OH-DPAT (213.48 fmol / mg, DE 28.06, p = 0.0003) compared with control (365.74 fmol / mg, 88.24). The binding [3H]-spiperone in the different groups was similar compared to control in both structures. Conclusions. The application of a single dose of 8-OH-DPAT (1mg/kg, sc) produced no changes in binding [3H]-8-OH-DPAT in the NAc and OFC, while the application after the RTN lesion appears to restore binding in the NAc. The binding [3H]-spiperone NAc and OFC is not altered after pharmacological or surgical intervention.