nNOS阳性神经元在兔脑干中的分布及衰老变化

Distribution of nNOS-containing neurons in rabbit brain stem and their functional changes caused by aging

利用SABC免疫组织化学方法,研究神经型一氧化氮合酶(nNOS)阳性神经元在家兔脑干中的分布和衰老变化。结果表明,家兔脑干内分布有丰富的nNOS阳性神经元;阳性神经元主要分布于动眼神经核、红核、脑桥核、三叉神经感觉主核以及脑干的网状结构等;在中央灰质周围、上丘(前丘)浅灰质层、臂旁核、中央上核、舌下神经核、下橄榄核、楔束核等核团也发现一些阳性神经元。对动眼神经核、红核、脑桥核、三叉神经感觉主核和延髓的外侧网状核这5个核团内阳性神经元的数量、胞体平均截面积和最长突起长度在5个年龄组的变化进行了比较。与成年兔相比,仔兔、青年兔阳性神经元的数量、胞体平均截面积和最长突起长度均没有显著性变化(P>0.05),但老年兔(36月龄)阳性神经元的数量和最长突起长度都显著减少(P<0.05),胞体平均截面积在动眼神经核、脑桥核、三叉神经感觉主核和外侧网状核减小,而在红核则增大(P<0.05)。结果提示,脑干内丰富的nNOS阳性神经元,可能通过其生成的NO参与内脏活动、感觉和运动的传导以及睡眠和觉醒等脑的高级整合功能的调节;随着年龄的增长,nNOS阳性神经元的衰老变化会影响NO的合成与释放,从而影响它们在脑干中的正常生理功能。

The research was designed to study the distribution of nNOS-containing neurons in rabbit brain stem and their functional changes for aging by means of SABC immunohistochemistry.The results showed that there are abundance of nNOS-containing neurons in rabbit brain stem;they are mainly distributed in nucleus of oculomotor nerve,red nucleus,pontine nucleus,main sensory nucleus of trigeminal nerve,reticular formation of brain stem.Besides,they also exist aroud the central gray matter,superficial gray matter layers of superior colliculus,parabrachial nucleus,superior central nucleus,hypoglossal nucleus,inferior olivary nucleus,cuneate nucleus etc.The differences of the number of nNOS-containing neurons,mean cross-sectional area of cell bodies and the length of the longest neurite in nucleus of oculomotor nerve,red nucleus,pontine nucleus,main sensory nucleus of trigeminal nerve and lateral reticular nucleus of medulla oblongata among 5 age groups were studied.Compared with those of adult rabbits,the number of nNOS-containing neurons,mean cross-sectional area of cell bodies and the length of the longest neurite did not change significantly （P 0.05） in cub and young group,but the number of nNOS-containing neurons and length of the longest neurite of the elderly rabbits （36 months） were significantly reduced （P 0.05）.The average cross-sectional area of cell bodies was reduced in nucleus of oculomotor nerve,pontine nucleus,main sensory nucleus of trigeminal nerve and lateral reticular nucleus,but it was increased in red nucleus（P 0.05）.The results suggest that there are abundance of nNOS-containing neurons in rabbit brain stem,which may take part in the activities,sensory and motor conduction of viscera and the regulation of advanced integration function such as sleeping and awakening;The aging of nNOS-containing neurons may influence synthesis and release of NO,thus affecting their physiological function in brain stem.