Animals
Male and female adult C57BL/6 mice (20–30 g) were maintained in a humidity level (55–65%) and temperature-controlled room on a 12-hours light/dark cycle with food (pelleted form) and water ad libitum . Animals were housed 8 per cage, with nesting material. All experiments were carried out in the light phase (between 07:00 a.m. and 7:00 p.m) and the animals were acclimatized to the laboratory room for at least 1 hour before the experiments.  The protocols employed in our study were approved by the Institutional Committee for Animal Care and Use of the Federal University of Santa Maria (UFSM; #9818180820).
The experimental protocols followed the guidelines of Animal Research Reporting In Vivo Experiments (ARRIVE) [39]. Also, experiments were performed using the current ethical guidelines for the investigation of experimental pain in conscious animals, and the minimum necessary number of animals and the intensity of noxious stimuli were used to demonstrate the consistent effects of the treatments. Group size of n=8 animals for behavioral experiments was determined using G*Power (v3.1).
All measurements of animal behavior were always performed by the same experimenter and blinded to drug administration or the group to be tested. ST (stressed) and NST (non-stressed) groups (both female and male) were divided and studied on the same day, and experiments were replicated on different days to generate results from the required number of mice (See on Fig 1. schematic representation of experimental design).