Pedersen Cort A, Boccia Maria L
Department of Psychiatry CB #7160, University of North Carolina, Chapel Hill, NC 27599-7160, USA.
Physiol Behav. 2003 Nov;80(2-3):233-41. doi: 10.1016/j.physbeh.2003.07.011.
Studies involving intracerebral administration of antiserum or antagonists have demonstrated that central oxytocin (OT) plays a prominent role in initiating but not maintaining postpartum maternal behavior in rats. There has been little investigation, however, of OT's influence on the levels of maternal behavior exhibited during the maintenance phase. We measured rat dam behavior during the 105-min observation periods preceding and beginning 2 h after intracerebroventricular infusion of the selective OT antagonist (OTA) (1 microg), or normal saline (NS) vehicle (5 microl) on postpartum days 2-3 and 6-7. Compared to NS, OTA significantly decreased pup licking as a proportion of dams' total oral grooming, increased self-grooming, decreased the frequency of elevated upright posture over pups and increased the frequency of lying prone on pups. Quiescent, kyphotic nursing was also significantly lower in OTA-treated dams. Other components of maternal behavior were not significantly affected by OTA or NS treatment. These findings suggest that central OT may shift the focus of the dams' oral grooming from self to pups and may also facilitate elevation of dams' upright posture over pups. Acute stress responses, maternal behavior and central OT receptor binding in adult rats have been linked to the amount of maternal licking and arched back, upright nursing received during infancy. OT activity in dams' brains may influence these developmental outcomes in their offspring by selectively regulating their pup licking and crouching posture.
涉及脑内注射抗血清或拮抗剂的研究表明，中枢催产素（OT）在启动大鼠产后母性行为中起重要作用，但对维持母性行为不起作用。然而，关于OT对维持阶段所表现出的母性行为水平的影响，研究甚少。我们在产后第2 - 3天和第6 - 7天，于脑室内注入选择性OT拮抗剂（OTA）（1微克）或生理盐水（NS）载体（5微升）之前及开始注入后2小时的105分钟观察期内，测量了母鼠的行为。与NS相比，OTA显著降低了母鼠舔舐幼崽占其总口腔梳理行为的比例，增加了自我梳理行为，降低了母鼠在幼崽上方直立姿势的频率，并增加了趴在幼崽身上的频率。接受OTA处理的母鼠安静、驼背式哺乳的情况也显著减少。母性行为的其他成分未受OTA或NS处理的显著影响。这些发现表明，中枢OT可能会将母鼠口腔梳理行为的重点从自我转向幼崽，还可能促进母鼠在幼崽上方直立姿势的提升。成年大鼠的急性应激反应、母性行为和中枢OT受体结合与幼年期接受的母鼠舔舐及弓背、直立哺乳的量有关。母鼠大脑中的OT活性可能通过选择性调节其舔舐幼崽和蹲伏姿势，影响其后代的这些发育结果。
