Original sentence: Importantly, analogous biochemical pathways and neural systems have already been known to be important in humans and other mammals, and the area remains a hot topic of research, as scientists inch toward understanding the problem of alcohol addiction
Edited sentence: Importantly, some of the analogous biochemical pathways and neural systems have been known to be important in alcohol's effects on humans, while the possibility that others may also be important remains unknown.Research of alcohol's effects on the nervous system remains a hot topic of research, as scientists inch toward understanding the problem of alcohol addiction