Effects of bilateral lesions in thalamic reticular nucleus and orbitofrontal cortex in a T-maze perseverative model produced by 8-OH-DPAT in rats.
OBJECTIVE
Stereotaxic lesions of the orbitofrontal-thalamic system, specifically the thalamic reticular nucleus (TRN), could be helpful to prevent perseverative behavior in rats produced by 8-OH-DPAT.


METHODS
Fifty rats were conditioned in a T-maze to measure the number of perseverations. Habituation was performed on days 1 and 2, baseline scores were obtained on day 3 and the final test was done on day 4 (chemical induction). Group I only received saline solution injection; group II was only submitted to 8-OH-DPAT; group III received pharmacological treatment with chlorimipramine (CMI) before 8-OH-DPAT administration; group IV and group V were submitted to stereotaxic bilateral lesions, one week before T-maze evaluation, in the TRN and orbitofrontal cortex (OFC), respectively and received 8-OH-DPAT administration.


RESULTS
No differences between groups were found at baseline on day 3 (p<0.05). Significant differences were found between days 3 and 4 of evaluation only in group II (p<0.01) and group V (p<0.001). Differences between groups on day 4 were significant (p<0.01).


CONCLUSIONS
TRN lesions were as effective as CMI administration to prevent the 8-OH-DPAT action. OFC lesions failed to prevent the perseverative behavior.
Andrade
Pablo
P
Functional Neurosurgery, Stereotaxy and Radiosurgery Unit, Mexico General Hospital, and Anáhuac University, School of Medicine and Psychology, Mexico City, Mexico. pandradem@gmail.com
Fernández-Guasti
Alonso
A
Carrillo-Ruiz
José D
JD
Ulloa
Rosa E
RE
Ramírez
Ylián
Y
Reyes
Rebeca
R
Jiménez
Fiacro
F
D017371:8-Hydroxy-2-(di-n-propylamino)tetralin / Q000633:toxicity; D000818:Animals; D002997:Clomipramine / Q000494:pharmacology; D005625:Frontal Lobe / Q000187:drug effects / Q000502:physiology*; D008297:Male; D018782:Maze Learning / Q000187:drug effects / Q000502:physiology*; D008568:Memory / Q000187:drug effects / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar; D017366:Serotonin Receptor Agonists / Q000633:toxicity; D017367:Selective Serotonin Reuptake Inhibitors / Q000494:pharmacology; D013787:Thalamic Nuclei / Q000187:drug effects / Q000502:physiology*; D013997:Time Factors
D017371:8-Hydroxy-2-(di-n-propylamino)tetralin; D002997:Clomipramine; D017366:Serotonin Receptor Agonists; D017367:Selective Serotonin Reuptake Inhibitors