Agrati Daniella, Uriarte Natalia
Sección Fisiología y Nutrición, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay.
Laboratorio de Neurociencias, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay.
Front Behav Neurosci. 2023 Jul 14;17:1239681. doi: 10.3389/fnbeh.2023.1239681. eCollection 2023.
Maternal behavior in mammals encompasses a complex repertoire of activities that ensure the survival of the offspring and shape their neural and behavioral development. The laboratory rat has been employed as a classic model for investigating maternal behavior, and recently with the use of advanced techniques, the knowledge of its neural basis has been expanded significantly. However, the standard laboratory testing conditions in which rats take care of a single litter impose constraints on the study of maternal flexibility. Interestingly, the reproductive characteristics of this species, including the existence of a fertile postpartum estrus, allow us to study maternal behavior in more complex and ethologically relevant contexts, even in laboratory settings. Here we review how maternal and sexual motivations interact during the postpartum estrus, shaping the behavioral response of females according to the presence of the pups and males. Next, we describe how impregnation during the postpartum estrus creates a new reproductive context in which mothers simultaneously care for two successive litters, adapting their responses to different behavioral and physiological demands of pups. These findings illustrate the behavioral adaptability of maternal rats to pups' needs and the presence of other reinforcers, as well as its dependence on the context. In our view, future perspectives in the field, by incorporating the use of cutting-edge techniques, should analyze maternal flexibility and its neural substrates in models that incorporate complex and challenging contexts. This approach would allow a more comprehensive understanding of brain circuits involved in the adaptive and flexible nature of parenting.
哺乳动物的母性行为包含一系列复杂的活动，这些活动确保后代的存活，并塑造其神经和行为发育。实验大鼠一直被用作研究母性行为的经典模型，最近随着先进技术的应用，对其神经基础的认识有了显著扩展。然而，大鼠在标准实验室测试条件下照顾一窝幼崽，这对母性灵活性的研究造成了限制。有趣的是，该物种的生殖特征，包括产后可育发情期的存在，使我们能够在更复杂且与行为学相关的背景下研究母性行为，甚至在实验室环境中也是如此。在此，我们回顾产后发情期母性动机和性动机如何相互作用，根据幼崽和雄性的存在塑造雌性的行为反应。接下来，我们描述产后发情期受孕如何创造一个新的生殖背景，在此背景下母亲同时照顾两窝相继出生的幼崽，并根据幼崽不同的行为和生理需求调整反应。这些发现说明了母鼠对幼崽需求及其他强化因素存在的行为适应性，以及其对环境的依赖性。我们认为，该领域未来的研究方向应通过运用前沿技术，在包含复杂且具有挑战性背景的模型中分析母性灵活性及其神经基础。这种方法将有助于更全面地理解参与育儿适应性和灵活性本质的脑回路。
