Urinary chemical cues affect light avoidance behaviour in male laboratory mice, Mus musculus

Chemical signals from conspecifics can influence the behaviour and neuroend ocrine axis of mice. Several different molecules are excreted with urine, d epending on hormonal level, and can indicate the sex of the emitter. In mal e mice, these chemicals are the major urinary proteins (MUPs) and some smal l volatile odorant molecues that are found bound to them. We tested adult m ales for light avoidance behaviour in a two-chamber apparatus, with one lig ht and one dark side, in the presence or absence of male urinary substances . The presence of chemical cues on either side of the cage was expected to modify light avoidance behaviour. The volatiles released from purified MUPS had the same effect as whole adult male urine, in that they induced a fast er onset of exploration of the light compartment. The results show that mic e can use the information carried by the odorant molecules released by MUPs to recognize the urine of male mice, and respond appropriately. (C) 1999 T he Association for the Study of Animal Behaviour.