studies of slime molds, argues that they are "no more than a bag of amoebae encased in a thin slime sheath, yet they manage to have various behaviors that are equal to those of animals who possess muscles and nerves with ganglia – that is, simple brains." traffic system inspirations atsushi tero of hokkaido university grew physarum in a flat wet dish, placing the mold in a central position representing tokyo and oat flakes surrounding it corresponding to the locations of other major cities in the greater tokyo area. as physarum avoids bright light, light was used to simulate mountains, water and other obstacles in the dish. the mold first densely filled the space with plasmodia, and then thinned the network to focus on efficiently connected branches. the network strikingly resembled tokyo's rail system. slime mold p. polycephalum was also used by andrew adamatzky from the university of the west of england and his colleagues world-wide in experimental laboratory approximations of motorway networks of 14 geographical areas: australia, africa, belgium, brazil, canada, china, germany, iberia, italy, malaysia, mexico, the netherlands, uk and us. the filamentary structure of slime molds such as p. polycephalum forming a network to food sources is similar to the large scale galaxy filament structure of the universe. this observation has led astronomers to use simulations based on the behaviour of slime molds to inform their search for dark matter. chemical signals the chemicals that aggregate slime molds are called acrasins. the first acrasin to be discovered was camp in dictyostelium discoideum. during the aggregation phase of their life cycle, dictyostelium discoideum amoebae communicate with each other by traveling waves of camp. there is an amplification of camp when they aggregate. in 2019, research done by university of tokyo found that while pre-stalk cells move toward camp, pre-spore cells ignored camp. the acrasin for polysphondylium violaceum has been purified in 1983. it is a dipeptide that has been named glorin. its major components are the amino acids, glutamic acid and ornithine. an amino group (nh3) and a carboxyl group (cooh) of the glutamic acid are blocked respectively by a propionyl group and an ethyl ester. an amino group on the ornithine molecule is blocked by a lactam ring. both cyclic amp and glorin are small molecules.