m.). Mice were acclimatized to the laboratory for at least 1 h before testing. Animals were used according to the guidelines of the Committee on Care and Use of Experimental Animal Resources, the Federal University of Santa Maria, Brazil. Non-spatial long-term memory was investigated using a step-down inhibitory avoidance task according to the method of Sakaguchi et al. (2006), with some modifications. Each mouse was placed on the platform, and the latency to step-down (four paws on the grid) was automatically recorded in training
and test sessions. In the training session, upon stepping down, the mouse received a 0.5 mA scrambled foot shock for 2 s. Test sessions were performed 24 h later, with the same procedure except that no shock was administered after stepping down; an upper cutoff time of 300 s was set. Six to eight animals were used per group. PEBT at the doses of 5 Ulixertinib concentration or 10 mg/kg orally (p.o.) (Souza et al., 2009), or vehicle (canola oil 10 ml/kg, p.o.) were given 1 h before Veliparib training (acquisition), immediately post-training (consolidation), or 1 h before test (retrieval). The oral route dominates contemporary drug therapy and is considered to be safe, efficient and easily accessible
with minimal discomfort compared to other routes of administration (Lennernãs, 2007). Spontaneous locomotor activity was measured in the open-field test (Walsh and Cummins, 1976). The open-field was made of plywood and surrounded by walls 30 cm in height. The floor of the open-field, 45 cm in length and 45 cm in width, was divided by masking tape markers into 9 squares (3 rows of 3). Each animal was placed individually at the center of the apparatus and observed for 4 min to record the locomotor (number of segments crossed with the four paws) and exploratory activities (expressed by the number of time rearing on the hind limbs). Six to eight animals
were used per group. The locomotor and exploratory activities were evaluated after the test session of the step-down inhibitory avoidance task. In order to investigate the possible mechanisms involved in the effect mafosfamide of PEBT on memory, glutamate uptake and release assays were carried out 1 h (training) or 24 h (test of memory) after oral administration of PEBT (10 mg/kg). Glutamate uptake was performed according to Thomazi et al. (2004). One and 24 h after oral administration of PEBT, mice were killed by cervical dislocation and the brains were immediately removed. Slices (0.4 mm) were obtained by transversally cuts of cortex and hippocampus using a McIlwain chopper. Experiments were made in triplicates. Slices were pre-incubated for 15 min at 37 °C in a Hank’s balanced salt solution (HBSS) containing (in mM): 137 NaCl, 0.63 Na2HPO4, 4.17 NaHCO3, 5.36 KCl, 0.44 KH2PO4, 1.26 CaCl2, 0.41 MgSO4, 0.49 MgCl2 and 1.11 glucose, adjusted to pH 7.2. Then, 0.66 and 0.