大鼠食管颈段神经形态的组化研究

本文采用多种组化方法结合神经银染技术,对大鼠的食管颈段神经形态观察发现:延髓内双侧疑核的咀侧端及迷走神经背核闩平而附近,分别见散在的多极和梭形标记细胞;颈前、中节、颈胸节和胸交感节(T_2-T_4),结状节,脊神经节(C_2-C_8)内均见标记细胞。 食管壁内的神经束及分支,由粗、细两类神经纤维组成。其中AchE阳性的胆碱能纤维占优势,分别见于外膜丛、肌内丛、粘膜下丛,腺体血管周围和粘膜肌内,粗纤维末梢伸向上皮基部和上皮之间,肌内的神经末梢呈结状膨大。外膜和肌肉见有神经节和散在的神经细胞。而食管壁内肾上腺素能纤维稀少,仅见于神经束和分支内及血管壁周围。     

Local and central sympathetic reflex control of blood flow in skeletal muscle and subcutaneous tissue in normal man

Summary. The effect of age and sex on relative changes in blood flow and vascular resistance in skeletal muscle and subcutaneous tissue during postural changes and during local increase in transmural pressure was studied in 33 healthy subjects. The intra-individual variation was studied in five subjects. Blood flow was measured by the local ¹³³Xenon wash-out method. No relation to age or sex was seen in the centrally elicited sympathetic vasoconstrictor responses in subcutaneous tissue and skeletal muscle and in the locally elicited vasoconstriction in subcutaneous tissue. A small, but statistically significant, correlation to sex and age was found in the local sympathetic vasoconstrictor response in skeletal muscle. The age correlation was caused only by an attenuated response in the young subjects below 40 years of age and may be fortuitous. The intra-individual variation was acceptably small. Based on the present results, a reduction in blood flow in skeletal muscle and subcutaneous tissue during centrally or locally elicited sympathetic vasoconstriction of 10% or less should be considered abnormal. The local ¹³³Xenon wash-out method is of value in examining patients suspected of dysfunction in the sympathetic part of the autonomic nervous system.     

Facial nerve reconstruction in neurofibromatosis 2

Summary Between 1979 and 1989, 13 patients with neurofibromatosis 2 underwent reconstructions of the facial nerve after removal of bilateral acoustic or facial neurinomas. Seven patients received hypoglossal-facial nerve anastomosis, and five reveived sural nerve grafting in the cerebellopontine angle. End-to-end anastomosis and intracranial-intratemporal sural grafting were performed for one patient each, respectively. Re-innervation was seen in all cases. The results were good in 11 cases. Two patients presented with poor results due to development of neurinomas close to the site of the nerve reconstruction. The importance of reconstructive surgery in patients with neurofibromatosis is stressed. The problems regarding failure of re-innervation in some cases and difficulties in their management are discussed.     

Muscle spasm induced sympathetic reflex bursts on microneurography in a case with pontine demyelination

Microneurography was performed in a 39-year-old woman with demyelination of the pontine white matter associated with muscle spasms in the lower extremities. Single bursts on the microneurogram were observed immediately after cessation of the spasm with no systemic changes in the blood pressure or heart rate. Voluntary tonic flexion of the lower extremities induced similar bursts with small amplitudes. These reflex bursts possessed a characteristic of muscle sympathetic nerve activity, because the latency between the peak of each burst and the prior R-wave on the electrocardiograph was constant. The occurrence of these bursts suggests that a segmental compensatory mechanism in the spinal cord may stabilize the muscle blood flow influenced by muscle contraction.     

The use of the rat facial nerve model to assess the effect of differing nerve anastomotic agents on the facial nerve

There are relatively few papers which prove that one nerve anastomotic agent for the facial nerve is superior to any other. Previous experiments on the division and anastomosis of the facial nerve have failed to consider the indeterminate variables involved, i.e. operator variability, controls and the reaction of the materials on normal nerve tissue. In this experiment, a variety of anastomotic agents were tested to see if the anastomotic agents themselves affected the extra-temporal facial nerve function. The absorbable suture, non-absorbable suture, glue and tube wrap used had no effect on normal nerve tissue or on the anastomosis of the sectioned facial nerve of the rat compared with simple laying together of the divided ends of the divided nerve.     

Vagus Nerve Stimulation Induces a Sustained Anticonvulsant Effect

Summary: Purpose: Stimulation of the vagus nerve can effectively abort several types of experimentally induced seizures in animals when administered near the time of seizure onset. Indirect evidence from human trials and animal studies suggests that the anticonvulsant effects of vagus nerve stimulation (VNS) extend beyond the duration of stimulation. We used the pentylenetetrazol model to determine whether VNS exerts a persistent anticonvulsant effect.
Methods: VNS (1 mA, 30 Hz, 500 μs pulse width) was administered continuously for 0, 1, or 60 min, or intermittently (30 s on, 5 min off) for 60 min, to awake and freely moving animals. After the end of stimulation, pentylenetetrazol (50 mg/kg i.p.) was administered to induce seizures. Time-course studies were also performed, consisting of 60 min of VNS followed by pentylenetetrazol injection after 0, 3-, 5-, and 10-min intervals.
Results: The greatest anticonvulsant effect occurred after 60 min of continuous VNS, which prevented convulsions in four of 12 rats and reduced significantly seizure duration, the total number of seizures, and number of tonic seizures. Intermittent VNS was less effective than continuous stimulation for 60 min, but more effective than that for 1 min. The anticonvulsant effect declined in a time-dependent fashion after discontinuation of VNS, with return to nonstimulated control values by 10 min.
Conclusions: The results of this study verify a persistent VNS-induced anticonvulsant effect and indicate that its efficacy is dependent on the cumulative stimulus duration.     

Sympathetic skin response and R–R interval variation in chronic uremic patients

Sympathetic skin response (SSR) and R–R interval variation (RRIV) were studied in 36 chronic, nondiabetic uremics to compare with their nerve conduction studies (NCS) and clinical dysautonomia. Abnormal SSR was noted in 5 (13.9%) patients, abnormal RRIV in 14 (38.9%), and abnormal NCS in 26 (72.2%). The patients were classified into three groups: group (GP) 1: “normal,” n = 21 (58.3%), normal RRIV and SSR; GP 2: “isolated parasympathetic dysfunction,” n = 10 (27.8%), abnormal RRIV and normal SSR; and GP 3: “sympathetic sudomotor dysfunction,” n = 5 (13.9%), abnormal SSR. A significant difference in age was found among the three groups (GP 3 > GP 2 > GP 1; P < 0.0001, ANOVA). After controlling the age factor, we still noted a tendency toward increasing NCS disturbances (distal latency and nerve conduction velocity of peroneal nerve; P < 0.05, multiple regression analysis) and frequencies of clinical autonomic symptoms (postural dizziness and impotence; P < 0.05, Mantel–Hanszel test) from GP 1 to GP 3. Patients with abnormal SSR (GP 3) displayed significantly higher frequencies of postural dizziness and impotence, indicating the relationship between an absence of SSR and clinical dysautonomia. © 1994 John Wiley & Sons, Inc.     

交感神经节培养的形态学观察

目的：观察交感神经节在体外培养中的生长和形态学特点。方法：无菌，取新生大鼠椎旁交感神经节，用Ｍａｘｉｍｏｗ培养法在相差显微镜下动态观察７天。终止２后，用Ｈｏｌｍｅｓ还原银染色法显示神经纤维。结果：交感神经节在壁后１２－１８ｈ开始生长，２４－４８ｈ由交感神经节长出的纤维长约０．５ｍｍ，７２－９６ｈ可见神经纤维伸长到１－２ｍｍ以上，并呈放射状向四周延伸。Ｈｏｌｍｅｓ还原银染色的标本中可见大量银染的神经     

Effects of Vagal and Sympathetic Nerves on Transmembrane Potential of Cardiac Ventricular Cells of Toad

The effects of vagal and sympathetic nerves on the transmembranepotentials of cardiac cells of toad were observed by means of microelectrodetechnique.The vagal nerve was stimulated there would be an increase in restingpotential and acceleration in repolarization of action potential(AP).However,ifatropine was used before stimulation the above-mentioned phenomena woulddisappear.When the sympathetic nerve was stimulated the AP amplitudeincreased,but resting potential(RP)remained the same.The increase of APresulted from the increases of overshoot.When the sympathetic nerve wasstimulated although the heart rate increased and the duration of AP wasshortened,the plateau phase of AP was prolonged.These results suggest that theeffects of vagal and sympathetic nerves on the transmembrane potential of cardiacventricular cells are coordinated and the normal characteritics of transmembranepotential are maintained by both the vagal and sympathetic nerves.