This study investigates the effect of histaminergic H4 agonist microinjection (VUF-8430) in the consolidation of emotional memory in mice submitted to the elevated plus maze (EPM) and the inhibitory avoidance test (IA) as well as in motor control in mice submitted to the Rotarod test. On the fourth day after surgical recovery from the procedure to implant a cannula, the animals will receive saline or VUF (0.15 nmol; 0.49 nmol; e 1.48 nmol/ 0.1 ¼l) administered post-exposure. All experiments will be performed on two consecutive days: Exposure (T1, D1 and R1) and 24h after, the re-exposure (T2, D2 and R2). Experiment 1: will be held in the EPM and the animals will be free to explore the maze for 5 min; in T1, immediately after exposure, the pharmacologic treatment will occurs; in T2, there will only be re-exposure to EPM. The decrease in activity in the open arms between T1 and T2, will infer the emotional memory. Experiment 2: will be held on IA and the pharmacological treatment is post-D1; in D2, the animals will only be re-exposed to the IA. The increase or decrease of latencies in D2 compared to D1 will infer the emotional memory. Experiment 3: will be held in the Rotarod where the rod-rotation speed will be 16 rpm for 300s and the latency to animal's fall is automatically measured by the apparatus. In R1, the will receive the drug treatment after R1. In R2, the animals will only be re-exposed, featuring motor learning. The increase or decrease in R2 latencies compared to R1 will infer the motor learning. The participation of VUF-8430 (dose to be defined) in the modulation of emotional memory determine another investigation: if its microinjection activates the protein expression in classical structures linked to emotional memory (cerebellar vermis, amygdala, hippocampus and prefrontal cortex) through the phosphorylation of CREB transcription factor, using the Western blotting technique (Experiment 4).
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