Stern J M, Kolunie J M
Department of Psychology, Rutgers-State University of New Jersey, New Brunswick 08903.
Physiol Behav. 1993 Nov;54(5):861-8. doi: 10.1016/0031-9384(93)90293-o.
Aggression toward conspecific and allospecific individuals by female mammals is much more likely during lactation than during other reproductive states, a behavior that serves to protect the young. Previous research revealed that removal of nipples (thelectomy) prepartum greatly reduces the likelihood of postpartum aggression in house mice, but not in Sprague-Dawley Norway rats. The present work shows that prepartum thelectomy has no effect on the likelihood or intensity of postpartum aggression toward a strange male intruder in Long-Evans rats. In contrast, anesthesia of each nipple and surrounding skin prevents or severely impairs the elicitation of biting and attacking by the intruder, but does not impair normal retrieval of pups. Following removal of the litter, maternal aggression occurs readily at 1 h and somewhat less so at 5 h, but is absent at 24 h. These data suggest that while maternal aggression in postpartum rats does not require suckling, it is dependent on somatosensory stimulation of the ventral trunk by pups; this stimulation apparently produces a motivational change that lasts several hours.
雌性哺乳动物在哺乳期比在其他生殖状态下更有可能对同种和异种个体表现出攻击性，这种行为有助于保护幼崽。先前的研究表明，产前切除乳头（乳头切除术）会大大降低家鼠产后攻击的可能性，但对斯普拉格-道利挪威大鼠却没有这种效果。目前的研究表明，产前乳头切除术对长-伊文斯大鼠产后对陌生雄性入侵者的攻击可能性或强度没有影响。相反，对每个乳头及其周围皮肤进行麻醉可防止或严重削弱入侵者引发的撕咬和攻击行为，但不会损害正常的幼崽找回行为。在移除幼崽后，母性攻击在1小时时很容易发生，在5小时时稍微少一些，但在24小时时则不会出现。这些数据表明，虽然产后大鼠的母性攻击不需要哺乳，但它依赖于幼崽对腹侧躯干的体感刺激；这种刺激显然会产生一种持续数小时的动机变化。
