投射到兔颈上神经节的脊髓交感节前神经元——HRP法研究

SYMPATHETIC PREGANGLIONIC NEURONS IN THE RABBIT SPINAL CORD PROJECTING TO THE SUPERIOR CERVICAL GANGLION——HRP STUDY

本研究用成年家兔12只、猴1只。将20μl%HRP注射于兔的颈上神经节内,在猴则用15%的HRP。动物存活3~6天。切片按Mesulam氏联苯胺蓝色法作成色反应,中性红复染。脊髓内HRP标记细胞仅见于注射例,12只兔共有标记细胞7908个。但每例的标记细胞数目不等,最多1690个,最少71个。标记细胞的纵长分布为12个脊髓节(C_(6)~T_(9)),但主要集中在T_(1)~T_(4)(占86.18%),特别是T_(2)和T_(3)(占56.22%)。高峰则位于T_(2)(29.10%)。标记的节前神经元细胞柱的首尾长度在各动物也不一样,最长的11节,占C_(7)~T_(9);最短的5节,占C_(3)~T_(4)。标记细胞的高峰在各例动物中分别位于T_(1)~T_(3),但主要集中在T2和T3。在脊髓的横切面上,标记细胞集中于4个细胞群,即:中间外侧核本部(ILp)、中间外侧核侧索部(ILf)、中介核(IC)和中介核旁室管部(ICpe)。后者又分为背侧部(ICped)和腹侧部(ICpev)。HRP标记细胞主要位于ILp,12只兔有92.99%位于此。位于ILf的标记细胞较少,占6.25%。位于IC和ICpe者则更少,分别占0.68%和0.08%。此外,在前角背侧部可偶见标记细胞。本文虽仅用1只猴,但标记细胞的分布模式与兔者基本相同。

The purpose of this research work is to find out the longitudinal distribution of the preganglionic neurons which project to the superior cervical sympathetic ganglion(SCSG).Experiments were performed on 12 adult rabbits and a monkey.Under sodium pentobarbital anesthesia,20 microliters of 10%HRP were injected slowly into the rabbit's SCSG.In the monkey,20 microliters of 15%HRP was injected.After a postoperative survival time of 3~6 days,the animals were perfused through,the ascending aorta with a cold fixative mixture composed of 2%paraformaldehyde and 1.25%glutaraldyhyde in 0.1mol phosphatebuffer at pH 7.4.The spinal cord segments C_(1)~L_(3)were cut serially in transverse plane on a cryostat at 48 micra.The HRP reaction product was demonstrated according to Mesulam's(1976)benzidine blue reaction method,and counterstained with neutral red.HRP labeled neurons in the spinal cord were located exclusively on the side ipsilateral to the injected SCSG.The total number of labeled cells were 7908 in 12 rabbits,but the number of labeled cells varied from animal to animal.The highest amount was 1690(423^(#))and the lowest amount was 71(425^(#)).The longitudinal distribution of the labeled cells in 12 rabbits was 12 segaments of the spinal cord(C_(6)~T_(9)),but the largest proportion(86.18%)of them was concentrated from T_(1)to T_(4),especially at the level of T_(2)and T_(3)(56.22%),and with a peak at T_(2)(29.10%).In cross section of the spinal cord.HRP-labeled cells were concentrated in four cell groups,they are:nucleus intermediolateralis pars principalis(ILp),nucleus intermediolateralis pars funicularis(ILf),nucleus intercalatus(IC)and nucleus intercalatus pars paraependymalis(ICpe).The latter is subdivided into dorsal portion and ventral portion.HRP positive cells were mainly located in the ILp,In 12 rabbits about 92.99%cells were located in it.A small portion of labeled cells(6.25%)were seen in the ILf.A few labeled neurons could be detected within,the IC(0.68%)and ICpe(0.08%).Furthermore,occasionally,very few labeled cells were found at the dorsol portion of the anterior horn.In the monkey,generally speaking,the pattern of the distribution of labeled cells was the same as the rabbit.