The applications of ultrasonic vocalization of rodents to the developmental and neurotoxicological test-battery of sociality

与对照组相比，高剂量组和低剂量组在PND 15产妇分离时的超声发声次数和持续时间均增加。然而，围产期甲状腺功能减退并不影响产妇分离时超声发声的频率。甲状腺功能减退导致发育迟缓。甲状腺功能低下的幼崽可能需要母亲更长时间的照顾，因此，它们仍然在PND 15上发出超声波。围产期甲状腺功能减退不影响成年期的超声发声。因此，围产期甲状腺功能减退对超声发声的影响直到成年后才消失。

The high-dose and low-dose groups exhibited increased number and duration of ultrasonic vocalizations under maternal separation on PND 15 compared with the control group. However, perinatal hypothyroidism did not affect the frequencies of ultrasonic vocalizations under maternal separation. Hypothyroidism causes developmental retardation. Hypothyroid pups might need maternal care for much longer period and consequently, they still emitted ultrasonic vocalizations on PND 15. Perinatal hypothyroidism did not affect ultrasonic vocalizations under paring in adulthood. Therefore, the effects of perinatal hypothyroidism on ultrasonic vocalization disappear until adulthood.