Effects of Anodal Transcranial Direct Current Stimulation (tDCS) Preconditioning Combined with Arachydonilcyclopropylamide (ACPA) on Exploratory Locomotion in Male Mice

Background: When confronting with an unfamiliar environment, animals exert orderly and complex behaviors called exploration. Locomotion is the most important part of exploratory behavior, but the principles of this behavior have not been fully understood yet. Here we studied the effects of the frontal region preconditioning with right and left frontal anodal transcranial direct current stimulation (tDCS) combined with the cannabinoid CB1 receptor agonist, arachydonilcyclopropylamide (ACPA) on locomotion in NMRI male mice. Materials and Methods: This study was carried out with 12 groups of NMRI mice (each group consisted of 8 mice), which were divided into 3 categories of ACPA alone, right, and left frontal anodal tDCS combined with ACPA. Anodal tDCS (with a current intensity of 0.2 mA for 20 minutes) was performed one day prior to ACPA intraperitoneal injection (0.01,0.05,0.1 mg/kg) and 15 minutes after injection the exploratory locomotion test was carried out. Results: The data showed that right frontal anodal tDCS combined with 0.01 and 0.05 mg/kg of ACPA and left frontal anodal tDCS combined with 0.05 mg/kg ACPA increased exploratory locomotion. Conclusions: Our finding suggested that combined implementation of right and left anodal tDCS and ACPA exerted anxiolytic properties and could increase exploratory related locomotion.