Original sentence: Studies using animal models have elucidated biochemical pathways, on which ethanol acts, in the nervous system.Traditionally, many biological studies are done in mammals, such as mice, rats, and non-human primates
Edited sentence: More recently, studies using animal models have begun to elucidate the effects of ethanol on the nervous system.Traditionally, many studies have been performed in mammals, such as mice, rats, and non-human primates