Role of pups' ultrasonic calls in a particular maternal behavior in Wistar rat: pups' anogenital licking.

Stimuli from pups maintain maternal behavior in the postpartum period. Olfactory cues are strongly involved in a particular component of maternal behavior: anogenital licking (MAGL). In addition to the olfactive stimulus, ultrasonic calls from pups are critical in ensuring pup survival. Pups emit vocalizations in distress situations. In a first experiment, pups' calls are recorded around MAGL sequences. In 2 out of 3 cases these calls appear to induce MAGL behavior from the dam with preputialectomised pups as well as with intact pups, but preputialectomised pups alone call again at the end of MAGL sequences. In a second experiment, ultrasonic calls from pups emitted just before AGL sequences were recorded and played back to dams in a glass-dish selection test. Whatever the pups' treatment (preputialectomised or sham), dams showed the specific ingestive behavior towards filter paper impregnated with dodecyl propionate (DP) when auditory cues (pups' ultrasonic calls) and olfactory cues (DP) were combined. The coordination of pups' ultrasonic calls and anogenital odor in MAGL behavior is discussed, ultrasonic calls might be an inducing factor and DP the regulating factor.