Guarraci Fay A, Holifield Caroline, Morales-Valenzuela Jessica, Greene Kasera, Brown Jeanette, Lopez Rebecca, Crandall Christina, Gibbs Nicole, Vela Rebekah, Delgado Melissa Y, Frohardt Russell J
Department of Psychology, Southwestern University, Georgetown, TX 78626, United States.
Department of Family and Child Development, Texas State University, San Marcos, TX 78666, United States.
Pharmacol Biochem Behav. 2016 Mar;142:36-41. doi: 10.1016/j.pbb.2015.12.003. Epub 2015 Dec 15.
The present study was designed to test the effects of methylphenidate (MPH) exposure on the maturation of endocrine functioning and sexual behavior. Female rat pups received either MPH (2.0mg/kg, i.p.) or saline twice daily between postnatal days 20-35. This period of exposure represents the time just prior to puberty as well as puberty onset. Approximately five weeks after the last injection of MPH or saline, female subjects were hormone-primed and tested during their first sexual experience. Subjects were given the choice to interact with a sexually active male or a sexually receptive female rat (i.e., the partner-preference test). The partner-preference paradigm allows us to assess multiple aspects of female sexual behavior. MPH exposure during peri-adolescence delayed puberty and, when mated for the first time, affected sexual behavior (e.g., increased time spent with the male stimulus and decreased the likelihood of leaving after mounts) during the test of partner preference. When monitoring estrous cyclicity, female subjects treated with MPH during peri-adolescence frequently experienced irregular estrous cycles. The results of the present study suggest that chronic exposure to a therapeutic dose of MPH around the onset of puberty alters long-term endocrine functioning, but with hormone priming, increases sensitivity to sexual stimuli.
本研究旨在测试哌甲酯（MPH）暴露对内分泌功能成熟和性行为的影响。雌性幼鼠在出生后第20至35天期间，每天接受两次MPH（2.0mg/kg，腹腔注射）或生理盐水注射。这段暴露期代表青春期前以及青春期开始的时间。在最后一次注射MPH或生理盐水大约五周后，对雌性受试动物进行激素预处理，并在它们的首次性经历期间进行测试。受试动物可以选择与性活跃的雄性大鼠或性接受期的雌性大鼠互动（即伴侣偏好测试）。伴侣偏好范式使我们能够评估雌性性行为的多个方面。青春期前后暴露于MPH会延迟青春期，并且在首次交配时，在伴侣偏好测试中会影响性行为（例如，增加与雄性刺激物相处的时间，并降低骑跨后离开的可能性）。在监测发情周期时，青春期前后接受MPH治疗的雌性受试动物经常出现不规则的发情周期。本研究结果表明，在青春期开始时长期暴露于治疗剂量的MPH会改变长期内分泌功能，但在激素预处理的情况下，会增加对性刺激的敏感性。
