Davis Lourdes K, Bolton Jessica L, Hanson Hannah, Guarraci Fay A
Department of Psychology, Southwestern University, Georgetown, TX 78626, U.S.A.
Departments of Pediatrics and Anatomy/Neurobiology, University of California, Irvine, Irvine, CA 92697, U.S.A.
Physiol Behav. 2020 Oct 1;224:113037. doi: 10.1016/j.physbeh.2020.113037. Epub 2020 Jun 27.
We used a modification of the limited bedding and nesting (LBN) model to evaluate the effects of early-life stress (ELS) on female and male reproductive physiology and behavior in Long-Evans rats. On postnatal day (PD) 2, dams and pups were transferred to a cage containing 100 mL of bedding (LBN condition) or to a cage containing 500 mL of bedding (control condition); bedding conditions remained until PD 10. In female rats, we measured vaginal opening, estrous cyclicity, female sexual behavior and motivation, and anxiety-like behavior. In male rats, we measured preputial separation, the development of male copulatory behavior, sexual motivation, and anxiety-like behavior. We found that relative to controls, female rats reared with LBN experienced precocious puberty and enhanced sexual motivation, but normal estrous cyclicity. Relative to controls, male rats reared with LBN experienced delayed puberty and enhanced sexual motivation, but normal development of copulatory behavior. Anxiety-like behavior was not affected by LBN in either female or male rats. In summary, the ELS of being reared with LBN affected the onset of puberty in the opposite direction in females and males, but enhanced sexual motivation in both. The current study is the first to examine the effects of ELS on sexual motivation using the LBN model. These findings further support the hypothesis that maternal care affects the development of sexual maturation and sexual motivation.
我们采用了有限垫料和筑巢（LBN）模型的改良版，以评估早期生活应激（ELS）对Long-Evans大鼠雌雄性生殖生理和行为的影响。在出生后第2天（PD2），将母鼠和幼崽转移到装有100毫升垫料的笼子（LBN条件）或装有500毫升垫料的笼子（对照条件）中；垫料条件维持到PD10。对于雌性大鼠，我们测量了阴道开口、发情周期、雌性性行为和动机以及焦虑样行为。对于雄性大鼠，我们测量了包皮分离、雄性交配行为的发育、性动机以及焦虑样行为。我们发现，与对照组相比，在LBN条件下饲养的雌性大鼠经历了青春期早熟且性动机增强，但发情周期正常。与对照组相比，在LBN条件下饲养的雄性大鼠青春期延迟且性动机增强，但交配行为发育正常。雌性和雄性大鼠的焦虑样行为均不受LBN影响。总之，在LBN条件下饲养所导致的ELS对雌性和雄性大鼠青春期的开始产生了相反方向的影响，但在两者中均增强了性动机。本研究是首次使用LBN模型研究ELS对性动机的影响。这些发现进一步支持了母体护理会影响性成熟和性动机发育的假说。
