Ultrasounds in young rodents. II. Changes with age in albino rats
Abstract
Pups from three litters of albino rats were monitored with an ultrasound detector while isolated under standard conditions. The experiment was planned in order to analyse quantitative and some qualitative changes with age in the ultrasonic distress calls. Systematic detections wtre made with a band-width of 5 kHz and a range of central frequencies varying from 35 to 55 kHz.
Detections within this range were low during the first days after birth, but they rose considerably with the opening of the ears (unfolding of external ears) and reached a maximum at this stage. Subsequently, the rate of calling decreased with successive days and progressively fell off to zero from day 21 onwards.
Changes in physical characteristics of the ultrasounds probably occurred with increasing age of the pups. It is likely that the distress calls stay at a constant frequency for longer periods during the days between the opening of the ears and the opening of the eyes, than during the earlier and later days.
The rate of distress calling does not seem to be related to the pups' effectiveness in eliciting maternal behaviour in adults because it is apparently lowest when the pups are most effective i.e. during the first days after birth.
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Interaction between postpartum stage and litter age on maternal caregiving and medial preoptic area orexin
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Quantitative and Qualitative Features of Neonatal Vocalizations in Mice
2018, Handbook of Behavioral NeuroscienceDuring the neonatal stage, vocal production represents a relevant communication system between pups and their mother. Ultrasonic vocalizations are most often emitted by mouse pups when they are far from the mother and the littermates or in response to different physical and social stimuli. Through the ultrasonic emission, pups communicate an emotional state that activates and elicits adequate maternal care responses. A quantitative and qualitative characterization of ultrasonic vocalizations by means of spectrographic analysis has been extensively exploited to measure fine changes in vocalizing behavior during the first postnatal weeks. The most frequently measured parameters of vocalizations are calling rate, peak of frequency, and sonographic sound shape. Interestingly, several factors such as strain, genotype, and pharmacological manipulations modulate neonatal ultrasonic production. The growing literature on ultrasonic vocalizations suggests that the study of the ultrasonic profile of calls represents a reliable and effective tool to assess mouse neurobehavioral development.
Ultrasonic Vocalizations of Young Mice in the Genus Peromyscus
2018, Handbook of Behavioral NeuroscienceThe genus Peromyscus is a vastly diverse group of North American rodents that exhibits important natural variation. This group is ideal for the study of pup ultrasonic vocalization because the species in this genus vary in social behavior and mating patterns that, in turn, may have selected for different types of offspring-parent vocal communication signals. Early authors in the study of rodent pup ultrasonic vocalizations noted the importance of Peromyscus for comparative studies. The types of vocalizations known from Peromyscus pups were remarkably well characterized in early descriptions with respect to the behavioral context. In Peromyscus pups, three types of ultrasonic vocalization types have been described that grade into adult types: sustained vocalization (also termed “syllable” vocalization), which is an isolation call; bark, which is an aversive call; and simple sweep, which is an affiliative call. We review intra- and interspecific comparative studies showing that pup ultrasonic calls may function in rapid maternal recognition, attraction, and retrieval, especially in pups that are not yet homeothermic, and may also be important for reducing parents’ aggression toward older pups. We advocate comparative studies among Peromyscus species using playbacks and suggest study of ultrasonic vocalizations in relation to parental investment, parental care, and complex group/family dynamics.
Biology, Development, and Ultrasonic Vocalizations of Bank Vole Infants
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Present address: Laboratoire de Psychologie, Université de Bruxelles.