[Comparison of the effects of the administration of fluoxetine and sertraline on the immune markers of the mu opioid receptor in the rat brain]. / Comparación de los efectos de la administración de fluoxetina y sertralina sobre el inmunomarcaje del receptor opioide mu en el cerebro de la rata.

ABSTRACT

INTRODUCTION: Chronic fluoxetine or imipramine administration in rats can generate a similar increase in the number of neural cells immunostained for mu opioid receptors in several prosencephalic regions. OBJECTIVE: The aim of the present work was to describe the effects of chronic sertraline administration on mu opioid receptor immunostaining in several rat brain prosencephalic regions, in order to compare with previously described fluoxetine effects. MATERIALS AND METHODS: Experimental animals were chronically administered with sertraline (i.p.). An immunocytochemical method, with the aid of a computerized image analysis system, was used in order to measure the number of neural cells immunostained for mu opioid receptors in several prosencephalic regions. RESULTS: Although chronic sertraline administration in rats generates a significant increase in the number of neural cells immunostained for mu opioid receptors in the caudatus-putamen, dentate gyrus, lateral septum and the frontal, parietal and piriform cortices, slight regional differences, with respect to fluoxetine action, were found. Thus, a more marked action on parietal cortex and lateral septum, and a lesser action on the frontal cortex, were found. CONCLUSION: Regional differences in sertraline effects, with respect to fluoxetine, could be related to a lesser incidence of psychomotor impairment.