Book Description

Rodent behavioral testing has been used to study brain functions since the 1890s and has become a gold-standard model in modern neuroscience. Up to the 1950s, most behavioral tests on laboratory rodent models were based on punishments and rewards. Both approaches can lead to a certain degree of animal pain or suffering. Punishments involved the employment of painful stimuli, typically electric shocks. Passive avoidance and fear conditioning tests, among the most widely used behavioral paradigms used to evaluate learning and memory in rodents, can be performed using only a single brief shock. Other tests, such as the active avoidance, might require up to tens or hundreds of shocks, strongly challenging the psychological welfare of the model animals. On the other hand, tests based on rewards, which apparently may seem more ethical, actually still induce suffering in the animals, as food rewards are almost always associated with a food restriction protocol, in order to motivate food-seeking behavior. Rodents are starved for days before starting the test and kept under food restriction for the whole duration of the test. The distress during the testing session is only a minimal part compared to the stress lived outside of the testing session, which is prolonged and continuous. Analogously, liquid rewards commonly rely on a previous water restriction protocol to use thirst as motivation. Animal stress is not only an ethical issue per se, but also an important factor potentially impacting on the reliability and reproducibility of experimental results.