Laboratório de Neurociências, Departamento de Anatomia, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo, Brazil.
Departamento de Patologia, Escola de Medicina Veterinária, Universidade de São Paulo, São Paulo, Brazil.
Dev Neurosci. 2022;44(6):629-642. doi: 10.1159/000526810. Epub 2022 Sep 5.
Hypoxic-ischemic encephalopathy is a severe clinical condition, among others, affecting the brain after offspring exposure to neonatal anoxia, which causes persistent sensorimotor and cognitive deficits. During peripartum, maternal behaviors are crucial for the healthy development of the offspring. In rats, the vocalization of newborns, around 40 kHz, corresponds to separation calls that encourage their mothers to retrieve them. Alterations in this pattern affect the maternal behavior addressed to the offspring. This study aimed to evaluate the maternal behavior of primiparous rats whose offspring were exposed to neonatal anoxia in P2 (postpartum day) during the lactation period, to assess mother-pup interactions through the pups' vocalization from P3 to P18. It also intends to quantify eventual neuronal alterations in the mothers' medial preoptic area after the last weaning (P21) through FOS protein expression. Anoxia offspring were found to reduce maternal behaviors toward them, increased frequency of separation calls in the male anoxia group, and reduced vocalization rate in the female anoxia group compared to their respective controls. Body weight gain reduction of males' and females' anoxia was observed. We concluded that anoxia exerts deleterious effects on the vocalization patterns of the pups, with sex differences that alter maternal behavior toward them. Impaired USV makes an additional negative impact on the already noxious effects of neonatal anoxia. Understanding those phenomena applies/contributes to guiding procedures and strategies to mitigate the deleterious outcomes and orient research concerning the complexity of neonatal anoxia events and the influence of maternal care quality concerning the pups, which should also be considered sex differences.
缺氧缺血性脑病是一种严重的临床情况，主要影响新生儿缺氧后大脑，导致持续性感觉运动和认知缺陷。围产期，母体行为对后代的健康发育至关重要。在大鼠中，新生儿约 40 kHz 的发声对应于分离叫声，鼓励其母亲将其取回。这种模式的改变会影响母体对后代的行为。本研究旨在评估初产大鼠的母性行为，其后代在哺乳期的 P2（产后第 2 天）期间暴露于新生儿缺氧，通过 P3 至 P18 期间幼崽的发声来评估母子互动。还旨在通过 FOS 蛋白表达来量化最后一次断奶（P21）后母亲的中脑前区的潜在神经元改变。发现缺氧后代减少了对它们的母性行为，雄性缺氧组的分离叫声频率增加，雌性缺氧组的发声率降低，与各自的对照组相比。观察到雄性和雌性缺氧者的体重增加减少。我们得出结论，缺氧对幼崽的发声模式产生有害影响，存在性别差异，从而改变了对它们的母性行为。受损的 USV 对新生儿缺氧的已有有害影响产生了额外的负面影响。了解这些现象有助于指导程序和策略，以减轻有害后果，并指导有关新生儿缺氧事件复杂性和母性照顾质量对幼崽影响的研究，还应考虑性别差异。
