Assessment of the effects of sex, age, and rearing condition on ultrasonic vocalizations elicited by pups during the maternal potentiation paradigm in C57BL/6J mice

Abstract

Isolation‐induced ultrasonic vocalizations (USVs) are important to elicit parental retrieval. This behavior is critical for the animal's survival and can be altered in models of developmental disorders. The potentiation of vocalizations in response to reunion with the dam, also called maternal potentiation, has been extensively studied in rats. However, the assessment of this paradigm in mice is scarce. In rats, the potentiation of vocalizations is dependent on rearing conditions. Since mice are the main species used for genetic models of diseases, we aimed to investigate how different factors such as age, sex, and rearing conditions can affect the potentiation of vocalizations in the maternal potentiation paradigm in mice. We carried out experiments using biparental (dam and sire) or uniparental rearing (dam). Pups were tested on postnatal days (PD) 9 or 12. Pups showed increased potentiation in both sexes at PD9 with uniparental rearing. Both rearing conditions and ages changed the repertoire from the first to the second isolation. Spectral parameters were affected by sex, rearing condition and reunion at PD9. At PD12, only duration was altered by reunion. We conclude that the performance of the pups in the maternal potentiation paradigm is dependent on age, sex, and rearing condition.

Quality evaluation tool for animal experiments and the usage specifications

“…In an early animal experimental system evaluation report where 1026 animal experimental research from 1957 to 2003 were retrospectively analyzed, the difference in the process of animal experiments has been identified to markedly affect treatment results, including whether lowtemperature treatment is applied in the animal grouping randomization and modeling process [5] . Further, the application of the blind method, as well as the standardized animal modeling and rearing condition, is also the non-negligible influencing factor [6][7][8] . Nevertheless, the existing specification of animal experiments is far from satisfactory.…”