The fluid and its components could be analyzed, which would enable us to elucidate the fluid function through ethological tests.The behavioral escape, but not the performance in test session, was the same for 20 Hz and 125 Hz frequencies. This modified step-down inhibitory avoidance Everolimus msds apparatus allowed us to control variables that have been not specified up to now. Our data demonstrates that not only the intensity but also the frequency of the applied current plays a key role in the performance in a step-down inhibitory avoidance and learning. This data of frequency is one of missing information in other studies using IAT. We observed learning with 0.35mA and 0.5mA at 62 and 125Hz but not at 20Hz. The latency to step up back to the platform during the training session was similar for all current intensities, even for the lowest applied current, regardless the frequency applied. It is important to emphasize that the possibility to programing the current frequencies in our apparatus with one modulate frequency allows to avoid the continuous animal muscle contraction provoked by the passing of electricity by the animal body. Also, the shape of bar avoid that animal hold the bar during the stimulus. In order to maintain this concept we needed to resolve the problem of bioimpedance influence in electric current. Thus, we changed the bars distribution, shape and turn on mode. In this way we cannot apply a scrambled footshock in this model, as the classical apparatus, because we need to turn off the bars. Furthermore, a comparison among traditional systems and the ours, is difficult because we cannot control the frequency in traditional apparatus, nor to measure the real intensity through the animals With the new apparatus presented here we were able: to abolish the influence of bioimpedance in the intensity of the current received by the animal; to precisely control the current received during the shocks delivery over the task; to control and constantly record the intensity and frequency of the effective current applied, enabling a full record of the entire experiment. There was a clear reduction in the decrement of effective current to only 0.1–3%, indicating an insignificant interference of bioimpedance. The guanosine, a guanine-based purine, plays important roles in the Central Nervous System, and has a well establish amnesic effect in vivo in rodents. Therefore we evaluated our new device using animals treated with i.p. injection of guanosine. We observed a significant diminishing effect of guanosine on step-down inhibitory avoidance memory even with a variable escape time. Taken altogether, this new device offers a substantial improvement in behavioral analysis in the step-down inhibitory avoidance task, by considering crucial parameters that havebeen never stated before.