Selective serotonin reuptake inhibitors alter NPY immunostaining in the rat hypothalamus

Chronic fluoxetine administration in rats generates a significant decrease in NPY immunostaining in the paraventricular and supraoptic nuclei, with respect to controls. However, a significant increase was found in arcuate nucleus. A lack of changes was observed in periventricular and suprachiasmatic nuclei, lateral hypothalamic area and medial preoptic area. Similar results were observed after chronic administration of sertraline. NPY expression is altered in appetite regulatory regions after in vivo chronic treatment with selective serotonin reuptake inhibitors, suggesting that arcuate-paraventricular NPY projection impairment is involved in the anorectic effects of these drugs.