The reduction in the concentration of serotonin in the CNS induces an increase in aggressive behavior in rats

MB MULLE BERNEDO; S GARCÍA; V ASTORGA; R CABRERA

Mar del Plata

Congreso; Reunión Anual de Sociedades de Biociencias SAIC-SAFE- SAB-SAP-AACYTAL-NANOMED-ar-HCS; 2019

SAIC-SAFE- SAB-SAP-AACYTAL-NANOMED-ar-HCS

Serotoninergic system modulates, among others, appetitive and aggressive behaviors. Main raphe nucleus outputs connect to olfactory bulbs (OB). We reported that pCPA i.p. administration (tryptophan hydroxylase inhibitor) increases the offensive/aggressive related behaviors at the 3rd and sixth days after administration. However offensive/aggressive behaviors highly increased on the 6th day. The aim was to examine if the depletion of 5-HT in the OB was related to the modifications in the offensive/aggressive behavioral manifestations.For this purpose, 60-day old male Sprague-Dawley rats were divided into 1) Naïve, 2) control i.p. saline injection and 3) pCPA 300 mg / kg, i.p. All groups were evaluated on day 6th in the arena using the resident/intruder test. At the end of the experiments, animals were euthanatized by decapitation and OB were obtained. The concentration of 5-HT and 5-HIIA were measured by HPLC. All the data were expressed as SEM ± (n=6) and analyzed by ANOVA I and Tukey post hoc test. A significant decrease (p≤0.001) of 5-HT and 5-HIIA after six days of pharmacological treatment was observed. The metabolic ratio between 5-HIIA / 5-HT showed a significant increase (p≤0.001). A significant negative correlation was observed between offensive/aggressive parameters and 5-HT concentration. We conclude that the depletion of 5-HT and 5-HIIA induced a dysfunction on the serotoninergic OB inputs and clear, direct relation with aggressive behavior in rats.