Mechanisms of suckling behavior

在新生大鼠幼崽中，舌下神经（XII）和面神经（VII）已在新生儿阶段切除口周解剖结构在母乳喂养中的功能作用进行了检查。第十二神经控制舌头运动，由两个功能不同的分支组成：与舌头伸出相关的内侧分支和与舌头缩回相关的外侧分支。双侧切除任一XII神经成分（主干：XII-主干;内侧分支：XII-med ;外侧分支：XII-lat）的新生大鼠幼仔未能泌乳且未存活。单侧第十二神经切除的新生儿表现出不同的哺乳能力，从而导致生存率的差异（XII-躯干：38% ; XII-MED：24% ; XII-LAT：92%）和出生后三周内出生后的生长，直到P21。结果表明，舌，特别是由XII-med神经支配的突出的肌肉成分，在乳房发育中起着至关重要的作用。 关于我们 进行本研究以确定VII和XII神经损伤对在不同发育阶段切除单侧或双侧VII和XII神经成分的大鼠的存活和生长的影响。在哺乳期，单侧以及双侧损伤的XII-trunk或XII-med神经产生干扰的牛奶摄入量，较低的存活率和生长迟缓的神经损伤的大鼠。在过渡期和咀嚼期，只有双边损伤的XII-主干或XII-MED神经产生干扰的食物摄入，其次是较低的生存率和生长迟缓，在这些动物。新生早期单侧VII神经损伤对大鼠的摄食量产生不利影响，导致神经损伤大鼠的存活率降低和严重的生长迟缓。结果表明，十二和VII神经切除大鼠的生存和生长有很大的不同，取决于神经损伤和发育年龄的动物在神经insulation. The功能的作用舌神经（LN）在哺乳期的大鼠幼崽进行了调查。单侧LN损伤的幼仔未表现出吮吸障碍，乳头附着时间无任何缩短（P11幼仔：559 ±16秒;对照值的105%），存活率保持较高（P11：100%）。双侧LN损伤的幼崽表现出吮吸障碍，乳头附着时间明显缩短（P11幼崽：220 ± 54秒;对照值的42%），存活率低（P1：33% ; P11：41%）。双侧眶下神经损伤或双侧球切除的幼崽根本没有显示出任何乳头附着，也没有幸存者，证实了上唇感觉和嗅觉在哺乳中的关键作用。基于这些发现，我们得出结论，舌感觉是非常重要的，但不是必要的吮吸。少

Functional roles of the perioral anatomical structures involved in breastfeeding were examined in newborn rat pups in which the hypoglossal (XII) and facial (VII) nerves had been resected at the neonatal stage. The XII nerve controls tongue movement and is comprised of two functionally distinct branches : the medial branch related to protrusion of the tongue and the lateral branch related to its retraction. Newborn rat pups with bilateral resection of either of the XII nerve components (main trunk : XII-trunk ; medial branch : XII-med ; lateral branch : XII-lat) failed to suckle milk and did not survive. Unilateral XII nerve-resected neonates showed different milk-suckling capabilities, which thus resulted in differences in survival rate (XII-trunk : 38% ; XII-med : 24% ; XII-lat : 92%) and postnatal growth during the postnatal three weeks until P21. The results indicate a crucial role of the tongue, especially of protruding muscular elements innervated by the XII-med nerve, in breastf … More eeding.The present study was performed to determine the effects of VII and XII nerve injuries on the survival and growth of rats in which the unilateral or bilateral VII and XII nerve components had been resected at different developmental stages. In the suckling period, unilateral as well as bilateral injuries in the XII-trunk or XII-med nerve produced disturbed milk intake, lower survival rates and growth retardation in the nerve-injured rats. In the transition and mastication periods, only bilateral injury in the XII-trunk or XII-med nerve produced disturbed food intake followed by lower survival rates and growth retardation in those animals. The unilateral VII nerve injury at the early neonatal stage caused deteriorating effects on food intake resulting in lower survival rate and severe growth retardation in the nerve-injured rats. The results indicate that the survival and growth of XII and VII nerve-resected rats differ considerably depending on the nerves injured and the developmental ages of the animals at the time of nerve insult.Functional role of lingual nerve (LN) in breastfeeding was investigated in rat pups during the suckling period. Unilaterally LN-injured pups did not show suckling disturbance with absence of any shortening (P11 pups : 559 ±16 sec ; 105% of the control value) in nipple attachment time and the survival rate remained high (P11 : 100%). Bilaterally LN-injured pups showed suckling disturbance with marked shortening (P11 pups : 220 ± 54 sec ; 42% of the control value) in nipple attachment time and a low survival rate (P1 : 33% ; P11 : 41%). Bilaterally infraorbital nerve-injured or bilaterally bulbectomized pups did not show any nipple attachment at all and there were no survivors, confirming the crucial roles of upper lip sensation and olfaction in suckling. Based on these findings, we conclude that tongue sensation is very important, but not essential for suckling. Less