Pardo Grace E, Cuevas Lucero B, Vásquez-Lizárraga Javier, Pary Alondra Casas, Pacheco-Otalora Luis F, Oruro Enver M
Laboratorio de Investigación en Neurociencias, Instituto Científico, Universidad Andina del Cusco, Peru.
Laboratorio de Investigación en Neurociencias, Instituto Científico, Universidad Andina del Cusco, Peru; Laboratorio de Neurocomputación, Sistemas Complejos y Simulación Social, Instituto Científico, Universidad Andina del Cusco, Peru.
Behav Brain Res. 2025 Aug 5;495:115769. doi: 10.1016/j.bbr.2025.115769.
Early mother-infant interactions are crucial for neurobehavioral development, yet how maternal care timing and organization respond to environmental adversity remains unclear. In altricial species like rodents, maternal behavior involves dynamic transitions that provide sensory experiences to developing pups. In this study, we examined how these transitions are influenced by environmental disruptions based on the timing of exposure. Using the limited bedding and nesting (LBN) paradigm, we exposed rat mothers and pups to LBN during three early postpartum windows: postpartum days (PPD) 2-4, 5-6, and 7-9, to assess its effects on infant development. Maternal behavior was analyzed using inferential statistics and network analysis. We assessed offspring outcomes on postnatal days (PND) 13-14, including body weight, eye opening, home-nest odor preference, nipple attachment, and ultrasonic vocalizations (USVs). We included infant outcomes from our prior study in which dams were exposed to LBN from PPD 2-9, with previously reported alterations in maternal behavior. LBN exposure on PPD 2-4 and 5-6 significantly altered maternal behavior, with increased high crouch posture, reduced off-nest behavior, and altered caregiving transitions. Network analysis revealed time window-specific pattern structure alterations, with fewer transitions between active and passive behaviors in LBN dams. No notable changes occurred when LBN was applied during PPD 7-9. Despite alterations in maternal care, pup outcomes remained largely intact. Only the LBN 2-4 group showed reduced body weight, and only LBN 2-9 pups emitted more low-frequency USVs. These findings suggest that while maternal behavior is sensitive to early disruptions, pup outcomes may be differentially affected depending on the timing and duration of exposure. Analyzing caregiving dynamics may contribute to future studies exploring how early caregiving influences long-term neurobehavioral development.
早期母婴互动对神经行为发育至关重要，但母亲照料的时间安排和组织方式如何应对环境逆境仍不清楚。在啮齿动物等晚成雏物种中，母性行为涉及动态转变，为发育中的幼崽提供感官体验。在本研究中，我们根据暴露时间考察了这些转变如何受到环境干扰的影响。使用有限垫料和筑巢（LBN）范式，我们在产后三个早期阶段将大鼠母亲和幼崽暴露于LBN环境中：产后第（PPD）2 - 4天、5 - 6天和7 - 9天，以评估其对幼崽发育的影响。使用推断统计和网络分析来分析母性行为。我们在出生后第（PND）13 - 14天评估幼崽的结局，包括体重、睁眼、对巢穴气味的偏好、乳头附着以及超声波发声（USV）。我们纳入了我们之前研究中的幼崽结局，在该研究中，母鼠从PPD 2 - 9天暴露于LBN环境，且之前已报道母性行为发生了改变。在PPD 2 - 4天和5 - 6天暴露于LBN显著改变了母性行为，高蹲姿势增加、离巢行为减少以及照料转变改变。网络分析揭示了特定时间窗口的模式结构改变，LBN母鼠的主动和被动行为之间的转变较少。在PPD 7 - 9天应用LBN时未出现明显变化。尽管母性照料发生了改变，但幼崽的结局在很大程度上保持完好。只有LBN 2 - 4组的体重降低，只有LBN 2 - 9组的幼崽发出更多低频USV。这些发现表明，虽然母性行为对早期干扰敏感，但幼崽的结局可能会根据暴露的时间和持续时间受到不同的影响。分析照料动态可能有助于未来探索早期照料如何影响长期神经行为发育的研究。
