Familial Sneddon's syndrome

We report the familial occurrence and apparent autosomal dominant inheritance of Sneddon's syndrome with variable clinical expression. The proband, a 40-year-old woman, presented with livedo reticularis and progressive neurological deterioration following a stroke. The diagnosis was confirmed by cerebral angiogram and skin biopsy, both showing the characteristic findings. Two of the patient's sisters were reported to have been similarly affected in the past. Her mother, two additional siblings and five of her seven children exhibited various vasospastic skin phenomena. Familial aggregation of this disorder may be common and a genetic basis may be involved in its pathogenesis.     

大鼠固定脑双侧脑桥尾侧网状核间联系的研究-Dil荧光标记法

本文用Di1荧光染料作轴突示踪剂,主要在大鼠死后固定脑组织上研究双侧脑桥尾侧网状核间联系。结果发现:大量标记纤维聚集成小束,自一侧脑桥尾侧网状核越过中线至对侧同名核,标记纤维呈桔红色、强荧光,直径约1-2微米,纤维主要集中该核的腹侧区。当这些纤维达对侧网状结构内的脑桥尾侧网状部位,其中有些纤维分为上升、下降技。下降纤维行于两侧网状结构的内侧部,同侧约可追踪4-7毫米,对侧约2毫米左右,纤维在下降过程中逐渐减少。活体注射后,可见少量越过中线纤维,并在两侧网状结构内侧部见到少量纤维和散在的终末样纤维。双侧锥体束内均见大量标记纤维,除少数例子外,对侧荧光强度强于同侧。少量交叉纤维入对侧锥体束后入脑桥尾侧网状核。本文还对新近使用于神经解剖研究的荧光染料Dil的优、缺点进行了探讨。     

对侧网状巨细胞核对大鼠脊髓背表面电位的影响

以浅麻醉和麻痹大鼠为对象,利用计算机平均技术记录强电流刺激腓肠神经诱发的脊髓背表面电位(CDP),观察对侧网状三细胞核(NGC)微量注射L一谷氨酸钠,使神经细胞兴奋后对CDP的影响.实验发现,对侧NGC神经细胞兴奋后,Aβ和Aσ纤维引起的P_1波及Aσ和C类纤维引起的N_3波减小,C类纤维引起的P_2波明显减小,N_4 波消失.以上结果提示:对侧NGC对细纤维诱发的CDP成分有抑制作用.     

Inhibitory action of a conditioning procedure on visual responsive neurons of the nucleus reticularis thalami in rats

Summary In urethane anesthetized rats neuronal responses of the visual part of nucleus reticularis thalami (vTR) to light were compared with those during pairing light as a conditioned stimulus (CS) with the electrical stimulation of the rat's tail (US). The intensity of the US was adjusted to the minimum required to evoke a slight freezing behavior in the awake rat. The firing rate of most vTR neurons decreased in the period between light and US application (P < 0.01). Significant response modulations to light were observed in 39% of the units, in most of them they persisted over an extinction period of 15 min. In addition, neurons which were predominantly inhibited by conditioning sometimes changed from regular spiking to a burst pattern. The results support the hypothesis that conditioning related facilitation of geniculate neurons observed in previous experiments can be explained at least partly by disinhibition of geniculate units from vTR.     

The nuclei of origin of brain stem enkephalin and substance P projections to the rodent nucleus raphe magnus

The sites of origin of brain stem enkephalin and substance P projections to the rodent nucleus raphe magnus were studied utilizing the combined horseradish peroxidase retrograde transport-peroxidase-antiperoxidase immunohistochemical technique. Several brain stem areas were found to contain both enkephalin- and substance P-like immunoreactive double labeled neurons following injection of horseradish peroxidase into the raphe magnus. Nuclei providing both enkephalin and substance P inputs to the raphe magnus include the nucleus reticularis paragigantocellularis, the nucleus cuneiformis, the nucleus solitarius and the trigeminal subdivision of the lateral reticular nucleus. Enkephalin projections to the raphe magnus were also found to originate from the dorsal parabrachial nucleus, the nucleus reticularis gigantocellularis pars α and from an area which corresponds to the A5 group of Dahlström &; Fuxe. Additional neurons containing substance P-like immunoreactivity and horseradish peroxidase reaction product were identified in the superior central raphe nucleus and the nucleus pontis oralis. The midbrain periaqueductal gray contributes very few enkephalin and substance P fibers to the raphe magnus.The nucleus raphe magnus is a key structure in the intrinsic analgesia system and it has also been implicated in other diverse and non-nonciceptive functions. The present study identifies several brain stem sites which provide enkephalin and substance P input to this raphe nucleus. Several of these nuclei have been implicated in central analgesic mechanisms or in non-nociceptive autonomic functions. The present investigation raises the possibility that these brain stem regions may modulate neuronal activity in the raphe magnus via enkephalin or substance P projections and thus influence the involvement of the raphe magnus in both opiate related mechanisms of pain control and non-nociceptive functions.     

The human oral raphe system

Summary Serial sections (15 m, 120 m, and 400 m) of nine brain stems treated with a combined lipofuscin pigment-Nissl stain were examined in order to delineate the three-dimensional conformation and subdivisions as well as the neuronal types of the human oral raphe system. Characteristic lipofuscin deposits within the somata of various cell types facilitated the demarcation of the oral raphe nuclei from surrounding structures. The dorsal, central, and linear raphe nuclei, e.g. the major subdivisions of the oral raphe system, share common traits as far as neuronal composition and pigmentation is concerned. The interfascicular subnucleus, the dorsofascicular subnucleus, and the intercalate subnucleus are minor subdivisions of the dorsal raphe nucleus. The intercalate one cannot be differentiated from surrounding areas in preparations solely stained for Nissl-material, while it can facilely be identified in combined pigment-Nissl preparations by virtue of differences in the pigmentation pattern. Our architectonical concept of the oral raphe system is in good accordance with the one derived from immunocytochemical investigations of serotonin-containing neurons in the human brain stem. Furthermore, five main neuronal types are described which constitute the oral raphe nuclei. They have been differentiated according to their characteristics as seen in combined pigment-Nissl preparations. I) Large ovoid to polygonal neurons with densely packed and intensely stained pigment granules. II) Similarily featured cells displaying dust-fine and faintly stained pigment granules. III) Medium-sized, ovoid to polygonal neurons with loosely distributed, small pigment granules. IV) Small ovoid neurons devoid of pigment or with only few, intensely stained granules. V) Small spindleshaped nerve cells with various amounts of intensely stained pigment granules. The morphometrical examination has revealed considerable overlapping in size between types I and II. A fact that would not allow a distinction in preparations solely stained for Nissl-material.     

大鼠延髓网状背侧亚核下行投射终末在脊髓灰质的分布

本研究应用PHA－L顺行追踪技术研究了大风延髓网状背测亚核（SRD）至脊髓灰质下行投射的终止部位。结果表明：SRD发出的下行纤维走行于脊髓的背外侧京中，从高位至低位，脊髓灰质中的PHA－L顺标终末的密度逐渐降低。SRD的下行投射终未在脊髓中具有明显的同侧分布优势，主要终止在同侧脊历灰质的Ⅳ～Ⅶ层和X层，Ⅰ、Ⅱ层中只有少量的标记终末，对侧脊髓灰质中除了在Ⅳ层和X层中有中等密度的颁标终末分布外，其余各层中几乎无标记终未、PHA－L顺标终未与BSI-B4标记的初级传入C纤维终末在Ⅰ．Ⅱ层内重叠公布．本研究为SRD在调控脊髓的伤害性信息传递方面也起重要作用这一论点提供了直接的形态学依据．     

Responses of nucleus reticularis tegmenti pontis neurons to vestibular stimulation in the rat

Summary Forty-nine neurons were recorded in the nucleus reticularis tegmenti pontis (NRTP) during horizontal vestibular and/or optokinetic stimulation in immobilized pigmented rats. During optokinetic stimulation, the response of NRTP neurons was either unidirectional (51%) or bidirectional (49%). Histological reconstruction showed that unidirectional neurons were located in the dorsal-medial part of NRTP, and bidirectional neurons in the lateral part. All neurons exhibited a response during pure vestibular sinusoidal stimulation in the frequency range 0.025 Hz-0.2 Hz. NRTP neurons were divided into two groups according to their threshold to vestibular stimulation. Group A neurons had a low threshold, a low spontaneous activity and their firing frequency slowly increased with acceleration. Group B neurons showed opposite characteristics. Phase and gain analysis suggested that NRTP neurons carry a head velocity signal. After hemiflocculectomy, the gain of the vestibular response of contralateral NRTP neurons increased. From these data, the role of NRTP in the horizontal vestibulo-oculomotor is discussed.Supported by DGRST 79.7.1012     

Properties of ipsilateral retinogeniculate afferents in albino and hooded rats

By recording single unit activities from the dorsal lateral geniculate nucleus in albino and hooded rats, physiological properties of the ipsilateral retinogeniculate afferents were compared with those of the contralateral ones. The results show that the ipsilateral retinogeniculate pathway was characterized by intermediate conduction velocities, relatively high incidence of the tonic response and the visual field representation of central 30° from the vertical midline on both sides.