Rostral Segments Research Articles

Aphis pomi and Aphis spiraecola (Hemiptera: Sternorrhyncha: Aphididae) in Europe - new information on their distribution, molecular and morphological peculiarities

Aphid species Aphis pomi (de Geer, 1773) is oligophagous on pomoideous host plants, whilst Aphis spiraecola Patch, 1914 is a polyphagous species alternating between Spiraea spp., its primary host, and a wide variety of secondary hosts, also including pomoideous species. Despite the biological distinction, these species are difficult to separate using their morphological characters. Partial sequences of mitochondrial COI and nuclear EF-1α genes were analyzed for samples from Central and Eastern Europe, Germany, Bulgaria, Italy, Turkey, China together with available data from GenBank. Interspecific pairwise sample divergences of the COI fragment ranged from 3.1 to 4.3%. One COI haplotype of A. pomi was predominant (n = 24), with a pan European distribution. The most abundant COI haplotype of A. spiraecola (n = 16) occurred in Lithuania, Latvia, Poland, Italy, Turkey and China. Interspecific pairwise sample divergences of the EF-1α fragment ranged from 0.6 to 1.2%. Analyzed partial sequences of EF-1α were identical in A. pomi. The most abundant EF-1α haplotype of A. spiraecola (n = 14) occurred in Lithuania, Poland, Italy, Turkey and China. The length of ultimate rostral segment appeared to be the most reliable morphological character for discrimination between apple and spirea aphid species. It allowed a 100% correct identification of A. pomi (n = 143) and 91.5% of A. spiraecola (n = 94) specimens in the European samples used for the molecular analysis. The existence of A. spiraecola in the Eastern Baltic region of Europe is documented for the first time.

A new species of Acyrthosiphon (Hemiptera, Aphididae) from France and Spain.

A new species in one of the largest genera of Macrosiphini (Hemiptera, Aphididae), Acyrthosiphon pilosum sp. n., is described from apterous and alate viviparous females and oviparous females from French and Spanish Mediterranean localities, living on species of Ononis (Fabaceae), mainly O. natrix. The new species is characterized by the presence of many accessory setae on the ultimate rostral segment, and usually five setae on the first tarsal segments, a combination that is not present in any other known Acyrthosiphon species; in addition marginal tubercles are present on prothorax and several of abdominal segments 2-5.

3种寄主上桃蚜的选择性及形态分化研究

PDF HTML阅读 XML下载 导出引用 引用提醒 3种寄主上桃蚜的选择性及形态分化 DOI: 10.5846/stxb201310202529 作者: 作者单位: 山西农业大学农学院,山西农业大学农学院,山西农业大学农学院,山西农业大学农学院,西北农林科技大学植保学院 作者简介: 通讯作者: 中图分类号: 基金项目: 旱区作物逆境生物学国家重点实验室课题(CSBAA2011-08); 山西农业大学博士启动项目(412564); 山西农业大学创新团队-有害生物绿色防控体系及应用(SXAUCG-201202). Performance and morphological differentiation of Myzus persicae (Hemiptera: Aphididae) on three types of host plants Author: Affiliation: College of Agriculture，Shanxi Agricultural University,College of Agriculture，Shanxi Agricultural University,,,Key Laboratory of Applied Entomology，College of Plant Protection，Northwest A＆F University， Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:桃蚜是一种重要的农业害虫,寄主广泛,种下分化复杂。以采自黄土高原旱作区桃树、烟草、甘蓝上的桃蚜为研究对象,通过叶片选择法、传统比较形态测定法研究了3种寄主上桃蚜的选择性及形态分化。结果表明:在3种寄主同时存在的情况下,烟草上的桃蚜嗜食烟草,表现为63.5%的桃蚜选择烟草叶,13.8%选择甘蓝叶,8.2%选择桃叶,而甘蓝和桃树上的桃蚜对原寄主没有表现出明显的嗜好性;从形态指标来看,3种寄主上的桃蚜在体长、触角末节长度、后足腿节长度、触角与体长的比例方面存在显著差异(P<0.05),说明这几个特征可以作为区分这3种寄主上桃蚜的依据。综合分析可以初步认为黄土高原旱作区烟草上的桃蚜可能形成了寄主专化型-烟草型。 Abstract: Myzus persicae (Sulzer), which is also called the green peach aphid, is one of the most important pests in China. It has a wide host range and its adaptation to plants differs depending on the host. The host biotypes of M. persicae have not been identified; this provides opportunities to study the host specificity of this aphid. Further research may contribute to our understanding of species diversity, which demonstrates the value of investigating the host biotype of the green peach aphid. In this study, aphids were collected from peach, tobacco, and cabbage in the dry area of the Loess Plateau, China. The preference of M. persicae for different host plants and their morphological differentiation were studied by leaf selection and traditional morphometric analysis. The results of the tropism of M. persicae toward hosts showed that the preference for the three plant hosts of aphids originally from cabbage and tobacco was not apparent in the former experiment, but it became clearer in the latter . Throughout the trial period, aphids originally feeding on peach leaves did not show a preference for any of the three plant species studied. In the presence of the three plant hosts, 63.5%, 13.8%, and 8.2% of aphids feeding on tobacco chose tobacco, cabbage, and peach leaves, respectively. This indicates that this type of aphid prefers tobacco. The aphids originally on cabbage or peach leaves had no obvious preference for their original host plants. The preference of aphids originally feeding on cabbage for the three plant hosts was cabbage leaves > tobacco leaves > peach leaves. Regarding host selection behavior of aphids from peach leaves, they were in greater abundance than those on tobacco and cabbage leaves during the first 4 hours after feeding. However, after 4 hours, a comparison of the three plants indicated the largest number of aphids was on tobacco leaves while cabbage leaves contained the fewest aphids. Morphological variation in eight M. persicae feeding characteristics on the three host plants was examined by morphological analysis. These characteristics were an important feature used to differentiate the aphids. A comparison of these aphid characteristics on the three hosts revealed they were similar, but there were exceptions. The ratio of the length of the tarsus and the ultimate rostral segment of the aphids originating from the three hosts was not significantly different (P>0.05). However, there was a significant difference (P<0.05) in body length, the length of the tentacle details and the metapodium femur, and the ratio of antenna length to body length. Based on these characteristics, which of the three host plants the aphids originated from could be determined. Additionally, body width and the length of the siphunculus of aphids feeding on tobacco and cabbage were significantly greater than those of aphids from peach (P<0.05). The caudas of aphids on cabbage were significantly larger than those of aphids from the other two hosts (P<0.05). The ratio of the length of the cornicles and caudas from aphids originally on tobacco was greater than that for aphids on cabbage; compared with the aphids on peach, there was no significant difference (P>0.05). In terms of the antenna, which is used more for feeling, the aphids on cabbage had the longest ones. Regarding each antenna section, there were differences in the length of antenna segments III, IV, and V, and the base of the tentacles. The exception was the length of antenna segments I and II, where there was no difference among the aphids. These results indicate that the morphological characteristics of the aphids on the three plant hosts may change based on the host characteristics. A comprehensive analysis showed that aphids originally from tobacco may have a specific host biotype. 参考文献 相似文献 引证文献

Revision of the genus Metoisops (Hemiptera: Heteroptera, Miridae, Isometopinae) from late Eocene European amber.

Metoisops akingbohungbei, M. groehni, M. punctatodiffusus, M. intergerivus, M. grabenhorsti, M. variabilis, and M. consimilis are described as new species from the late Eocene Baltic, Ukrainian, (Rovno) and Saxonian (Bitterfeld) amber. The new diagnosis of the genus Metoisops and also all species of this genus presented, along with illustrations. An analysis of all studied specimens referring to of Metoisops from different Eocene European amber demonstrates the great variability of their features, and allows for differentiation of species. Ratios of the width and length of body, eye, vertex, antennal and rostral segments, pronotum, mesoscutum and scutellum, claval commissura, length of hind femur, tibia and tarsus, corium and cuneus length, as well as ratio of membrane cell's width and length of all 9 species of the genus Metoisops are presented.

Coordination of fictive motor activity in the larval zebrafish is generated by non-segmental mechanisms.

The cellular and network basis for most vertebrate locomotor central pattern generators (CPGs) is incompletely characterized, but organizational models based on known CPG architectures have been proposed. Segmental models propose that each spinal segment contains a circuit that controls local coordination and sends longer projections to coordinate activity between segments. Unsegmented/continuous models propose that patterned motor output is driven by gradients of neurons and synapses that do not have segmental boundaries. We tested these ideas in the larval zebrafish, an animal that swims in discrete episodes, each of which is composed of coordinated motor bursts that progress rostrocaudally and alternate from side to side. We perturbed the spinal cord using spinal transections or strychnine application and measured the effect on fictive motor output. Spinal transections eliminated episode structure, and reduced both rostrocaudal and side-to-side coordination. Preparations with fewer intact segments were more severely affected, and preparations consisting of midbody and caudal segments were more severely affected than those consisting of rostral segments. In reduced preparations with the same number of intact spinal segments, side-to-side coordination was more severely disrupted than rostrocaudal coordination. Reducing glycine receptor signaling with strychnine reversibly disrupted both rostrocaudal and side-to-side coordination in spinalized larvae without disrupting episodic structure. Both spinal transection and strychnine decreased the stability of the motor rhythm, but this effect was not causal in reducing coordination. These results are inconsistent with a segmented model of the spinal cord and are better explained by a continuous model in which motor neuron coordination is controlled by segment-spanning microcircuits.

Pentalonia nigronervosaCoquerel andPentalonia caladiivan der Goot (Hemiptera: Aphididae) and Their Relationship to Banana Bunchy Top Virus in Micronesia

Geographical distribution of Pentalonia nigronervosa and P. caladii, and incidence of banana bunchy top virus (BBTV) were determined in Micronesia. Aphids and plant tissues were collected from banana and nonbanana hosts of Petrtalonia aphids in Palau, Yap, Guam, Rota, Tinian, Saipan, Pohnpei, Kosrae, and Majuro. Aphids were identified based on host species from which they were collected and on morphometric analysis of length of ultimate rostral segment. All plant samples were tested for presence or absence of BBTV using a triple antibody sandwich enzyme-linked immunosorbent assay (TAS-ELISA). TAS-ELISA analysis confirmed BBTV to be present on Guam, Saipan, and Rota, but BBTV was not detected elsewhere in Micronesia.

Histological correlation of diffusional kurtosis and white matter modeling metrics in cuprizone-induced corpus callosum demyelination.

The cuprizone mouse model is well established for studying the processes of both demyelination and remyelination in the corpus callosum, and it has been utilized together with diffusion tensor imaging (DTI) to investigate myelin and axonal pathology. Although some underlying morphological mechanisms contributing to the changes in diffusion tensor (DT) metrics have been identified, the understanding of specific associations between histology and diffusion measures remains limited. Diffusional kurtosis imaging (DKI) is an extension of DTI that provides metrics of diffusional non-Gaussianity, for which an associated white matter modeling (WMM) method has been developed. The main goal of the present study was to quantitatively assess the relationships between diffusion measures and histological measures in the mouse model of cuprizone-induced corpus callosum demyelination. The diffusional kurtosis (DK) and WMM metrics were found to provide additional information that enhances the sensitivity to detect the morphological heterogeneity in the chronic phase of the disease process in the rostral segment of the corpus callosum. Specifically, in the rostral segment, axonal water fraction (d = 2.6; p < 0.0001), radial kurtosis (d = 2.0; p = 0.001) and mean kurtosis (d = 1.5; p = 0.005) showed the most sensitivity between groups with respect to yielding statistically significant p values and high Cohen's d values. These results demonstrate the ability of DK and WMM metrics to detect white mater changes and inflammatory processes associated with cuprizone-induced demyelination. They also validate, in part, the application of these new WMM metrics for studying neurological diseases, as well as helping to elucidate their biophysical meaning.

Alterations of protein composition along the rostro-caudal axis after spinal cord injury: proteomic, in vitro and in vivo analyses.

Based on proteomic analyses we investigated the differences of released molecules in the conditioned media (CM) from the spinal cord central lesion and adjacent rostral and caudal segments at 3, 7, and 10 days after spinal cord injury (SCI), in order to specify the molecular environment within greater extent of tissue damage. Proteins found in CM were analyzed by shot-gun MS using nanoLC coupled to an orbitrap. The results showed some specific proteins at each site of the lesion at 3days. Among the proteins from rostral and lesion segments, some are related to chemokines, cytokines or to neurogenesis factors. In contrast, proteins from caudal segments are more related to necrosis factors. The CM from each spinal segment were used in vitro, on microglial BV2 cell lines and DRGs explants, showing a lesion site-dependent impact on microglia activation and DRGs neurite outgrowth. In addition, while naive BV2 cells exhibited insignificant staining for CX3CR1 receptor, the level of CX3CR1 was strongly enhanced in some BV2 cells after their stimulation by CM collected from SCI. The molecular data might correlate with different polarization of activated microglia and macrophages along the rostro-caudal axis following acute injury. This was partially confirmed in vivo with CX3CR1 receptor, revealing higher expression in the rostral segment, with potential neuroprotective action. In addition, the neurotrophic factors released from rostral and lesion segments enhanced outgrowth of DRGs explants. Taken together these data suggest that regionalization in terms of inflammatory and neurotrophic responses may occur between rostral and caudal segments in acute SCI.

Rostral spinal cord segments are sufficient to generate a rhythm for both locomotion and scratching but affect their hip extensor phases differently

Rostral segments of the spinal cord hindlimb enlargement are more important than caudal segments for generating locomotion and scratching rhythms in limbed vertebrates, but the adequacy of rostral segments has not been directly compared between locomotion and scratching. We separated caudal segments from immobilized low-spinal turtles by sequential spinal cord transections. After separation of the caudal four segments of the five-segment hindlimb enlargement, the remaining enlargement segment and five preenlargement segments still produced rhythms for forward swimming and both rostral and pocket scratching. The swimming rhythm frequency was usually maintained. Some animals continued to generate swimming and scratching rhythms even with no enlargement segments remaining, using only preenlargement segments. The preenlargement segments and rostral-most enlargement segment were also sufficient to maintain hip flexor (HF) motoneuron quiescence between HF bursts [which normally occurs during each hip extensor (HE) phase] during swimming. In contrast, the HF-quiescent phase was increasingly absent (i.e., HE-phase deletions) during rostral and pocket scratching. Moreover, respiratory motoneurons that normally burst during HE bursts continued to burst during the HF quiescence of swimming even with the caudal segments separated. Thus the same segments are sufficient to generate the basic rhythms for both locomotion and scratching. These segments are also sufficient to produce a reliable HE phase during locomotion but not during rostral or pocket scratching. We hypothesize that the rostral HE-phase interneurons that rhythmically inhibit HF motoneurons and interneurons are sufficient to generate HF quiescence during HE-biased swimming but not during the more HF-biased rostral and pocket scratching.

Central Canal Ependymal Cells Proliferate Extensively in Response to Traumatic Spinal Cord Injury but Not Demyelinating Lesions

The adult mammalian spinal cord has limited regenerative capacity in settings such as spinal cord injury (SCI) and multiple sclerosis (MS). Recent studies have revealed that ependymal cells lining the central canal possess latent neural stem cell potential, undergoing proliferation and multi-lineage differentiation following experimental SCI. To determine whether reactive ependymal cells are a realistic endogenous cell population to target in order to promote spinal cord repair, we assessed the spatiotemporal dynamics of ependymal cell proliferation for up to 35 days in three models of spinal pathologies: contusion SCI using the Infinite Horizon impactor, focal demyelination by intraspinal injection of lysophosphatidylcholine (LPC), and autoimmune-mediated multi-focal demyelination using the active experimental autoimmune encephalomyelitis (EAE) model of MS. Contusion SCI at the T9–10 thoracic level stimulated a robust, long-lasting and long-distance wave of ependymal proliferation that peaked at 3 days in the lesion segment, 14 days in the rostral segment, and was still detectable at the cervical level, where it peaked at 21 days. This proliferative wave was suppressed distal to the contusion. Unlike SCI, neither chemical- nor autoimmune-mediated demyelination triggered ependymal cell proliferation at any time point, despite the occurrence of demyelination (LPC and EAE), remyelination (LPC) and significant locomotor defects (EAE). Thus, traumatic SCI induces widespread and enduring activation of reactive ependymal cells, identifying them as a robust cell population to target for therapeutic manipulation after contusion; conversely, neither demyelination, remyelination nor autoimmunity appears sufficient to trigger proliferation of quiescent ependymal cells in models of MS-like demyelinating diseases.

Nitric oxide-mediated modulation of the murine locomotor network

Spinal motor control networks are regulated by neuromodulatory systems to allow adaptability of movements. The present study aimed to elucidate the role of nitric oxide (NO) in the modulation of mammalian spinal locomotor networks. This was investigated with isolated spinal cord preparations from neonatal mice in which rhythmic locomotor-related activity was induced pharmacologically. Bath application of the NO donor diethylamine NONOate (DEA/NO) decreased the frequency and modulated the amplitude of locomotor-related activity recorded from ventral roots. Removal of endogenous NO with coapplication of a NO scavenger (PTIO) and a nitric oxide synthase (NOS) blocker [nitro-l-arginine methyl ester (l-NAME)] increased the frequency and decreased the amplitude of locomotor-related activity. This demonstrates that endogenously derived NO can modulate both the timing and intensity of locomotor-related activity. The effects of DEA/NO were mimicked by the cGMP analog 8-bromo-cGMP. In addition, the soluble guanylyl cyclase (sGC) inhibitor ODQ blocked the effects of DEA/NO on burst amplitude and frequency, although the frequency effect was only blocked at low concentrations of DEA/NO. This suggests that NO-mediated modulation involves cGMP-dependent pathways. Sources of NO were studied within the lumbar spinal cord during postnatal development (postnatal days 1–12) with NADPH-diaphorase staining. NOS-positive cells in the ventral horn exhibited a rostrocaudal gradient, with more cells in rostral segments. The number of NOS-positive cells was also found to increase during postnatal development. In summary, we have shown that NO, derived from sources within the mammalian spinal cord, modulates the output of spinal motor networks and is therefore likely to contribute to the fine-tuning of locomotor behavior.

Level Diagnosis of Cervical Compressive Myelopathy: Signs, Symptoms, and Lesions Levels

Background: To elucidate signs and symptoms corresponding to each vertebral level for level-specific diagnoses. Methods: We studied 106 patients with cervical compressive myelopathy. Patients who showed a single compressive site on magnetic resonance imaging ( MRI ) were selected, and signs, symptoms, and the levels of the MRI lesions were studied. Results: Five of 12 patients (41.7%) with C4-5 intervertebral level lesions showed decreased or absent biceps and brachioradialis reflexes, while 4 of these patients (33.3%) showed generalized hyperreflexia. In comparison, 5 of 24 patients (20.8%) with C5-6 intervertebral level lesions showed decreased or absent triceps reflexes; however, 9 of these patients (37.5%) showed decreased or absent biceps and brachioradialis reflexes. Conclusions: C4-5 intervertebral level lesions not only showed C6 segment signs but also showed more rostral segment signs. Similarly, C5-6 intervertebral level lesions not only showed C7 segment signs but also showed C6 or more rostral segment signs. J Neurol Res. 2013;3(5):135-141 doi: https://doi.org/10.4021/jnr236w

Intraspinal stretch receptor neurons mediate different motor responses along the body in lamprey

In lampreys, stretch receptor neurons (SRNs) are located at the margins of the spinal cord and activated by longitudinal stretch in that area caused by body bending. The aim of this study was a comprehensive analysis of motor responses to bending of the lamprey body in different planes and at different rostrocaudal levels. For this purpose, in vitro preparation of the spinal cord isolated together with notochord was used, and responses to bending were recorded from SRNs, as well as from motoneurons innervating the dorsal (dMNs) and ventral (vMNs) parts of a myotome. It was found that SRNs were activated on the convex (stretched) side of the preparation during bending both in the yaw and in the pitch plane. By contrast, responses of motoneurons depended on the site and plane of bending. In the yaw plane, concave responses to bending of rostral segments and convex responses to bending of mid-body segments prevailed. In the pitch plane, convex responses in dMNs and concave responses in vMNs to bending in mid-body segments prevailed. These spinal reflexes could contribute to feedback regulation of locomotor body undulations and to the control of body configuration during locomotion. After a longitudinal split of the spinal cord, only convex responses in motoneurons were present, suggesting an important role of contralateral networks in determining the type of motor response. Stimulation of the brainstem changed the type of motor response to bending, suggesting that these spinal reflexes can be modified by supraspinal signals in accordance with different motor behaviors.

Segmental architecture of the spinal accessory nerve

Nicolas de Tribolet, MD Editor-in-Chief Acta Neurochirurgica The spinal accessory nerve has become a workhorse for brachial plexus reconstruction following traumatic peripheral nerve injury. It is frequently used as an extraplexal motor donor for transfer to injured nerves, including the suprascapular nerve, musculocutaneous nerve, and others [1, 10]. The spinal accessory nerve’s large motor fiber content [3] and infrequent injury from brachial plexus trauma [2] has yielded a high success rate for these transfers [9, 11]. The concept of nerve transfers for peripheral nerve injuries has been extended to apply to spinal cord injury patients [4]— transferring supralesional nerves into infralesional nerves to enable cortical control of the targeted muscle. A 36-year-old man presented to our clinic for consideration of reconstructive surgery for a high cervical cord injury from a surfing accident 14 years previously. His injury consisted of cervical fractures from C1 through C6, with burst fracture and dislocation of C4 and C5. His current lowest level of function was C4 (ASIA impairment scale A); his motor exam consisted of full strength shoulder shrug bilaterally, but without motor control of any muscle of the left upper extremity. On the right he had weak 4/5 (MRC scale) shoulder abduction and 2/5 external rotation, 3/5 pectoralis major muscle, 4/5 elbow flexion, and trace flexor carpi radialis contraction. Our goals were to identify transferable nerves to achieve elbow flexion on the left; the only donor source would be the spinal accessory nerve. Needle EMG was performed to assess for evidence of denervation of the trapezius muscle that would indicate fewer healthy axons for transfer. Very mild chronic denervation was observed in the middle trapezius, whereas there was moderate chronic denervation in the lower trapezius, including polyphasic potentials, rapid firing, and large motor unit potentials (Fig. 1). The pattern of denervation suggested correlation with his spinal cord injury: an MRI demonstrated near-total loss of spinal cord parenchyma from mid-cervical three to rostral cervical six vertebral bodies which form the C4 through C6 nerves. A segmental pattern of innervation of the trapezius muscle has not been previously defined. Several animal models have shown consistent innervation of the trapezius muscle by the C1–C7 spinal cord segments [5], with the predominant innervation deriving from C2–C6 [6, 8, 12]. The bilateral EMG findings suggest to us that the trapezius muscle is segmentally innervated, with rostral muscle coordinated by rostral cervical spinal segments and caudal muscle coordinated by caudal cervical spinal segments. The salient message, along with the previously undetected pattern of innervation, is that the concepts of nerve transfers for brachial plexus injury cannot be uniformly applied to nerve transfers for spinal cord injury. Although the spinal accessory nerve is a cranial nerve by its dural exit, it is a spinal nerve by origin of its motor neuron pool [7]. This segmental architecture is susceptible to high cervical spine injury, reducing the ability of the spinal accessory nerve to serve as a source for transfer of healthy motor neurons. Preoperative electrodiagnostic evaluation of the quality of the innervation of the trapezius muscle is essential for consideration of the M. A. Mahan (*) Division of Neurological Surgery, Barrow Neurological Institute, St. Joseph’s Hospital and Medical Center, 350 W. Thomas Road, Phoenix, AZ 85013, USA e-mail: Neuropub@dignityhealth.org

Lateral convexial tributary sinus of superior sagittal sinus. A rare anatomic variation and the importance of its recognition

Developmental anomalies of the brain and corresponding natomic variations have a strong potential to influence the interretation of imaging and neurosurgical planning. Several anatomic variations of the superior sagittal sinus (SSS) as nilateral hypoplasia or aplasia of the rostral segment, duplication r fenestration are usual findings of cerebral angiograms. We report a variation, a convexial lateral tributary sinus (LTS) of he superior sagittal sinus. According to our review, such a lateral ributary sinus must be a rare variation, since our literature search as shown a lack of any report describing this variation. Short review of the relevant embryology is presented. The mportance of its recognition in the preoperative neurosurgical lanning is emphasized.

Identification of multisegmental nociceptive afferents that modulate locomotor circuits in the neonatal mouse spinal cord

Compared to proprioceptive afferent collateral projections, less is known about the anatomical, neurochemical, and functional basis of nociceptive collateral projections modulating lumbar central pattern generators (CPG). Quick response times are critical to ensure rapid escape from aversive stimuli. Furthermore, sensitization of nociceptive afferent pathways can contribute to a pathological activation of motor circuits. We investigated the extent and role of collaterals of capsaicin-sensitive nociceptive sacrocaudal afferent (nSCA) nerves that directly ascend several spinal segments in Lissauer's tract and the dorsal column and regulate motor activity. Anterograde tracing demonstrated direct multisegmental projections of the sacral dorsal root 4 (S4) afferent collaterals in Lissauer's tract and in the dorsal column. Subsets of the traced S4 afferent collaterals expressed transient receptor potential vanilloid 1 (TRPV1), which transduces a nociceptive response to capsaicin. Electrophysiological data revealed that S4 dorsal root stimulation could evoke regular rhythmic bursting activity, and our data suggested that capsaicin-sensitive collaterals contribute to CPG activation across multiple segments. Capsaicin's effect on S4-evoked locomotor activity was potent until the lumbar 5 (L5) segments, and diminished in rostral segments. Using calcium imaging we found elevated calcium transients within Lissauer's tract and dorsal column at L5 segments when compared to the calcium transients only within the dorsal column at the lumbar 2 (L2) segments, which were desensitized by capsaicin. We conclude that lumbar locomotor networks in the neonatal mouse spinal cord are targets for modulation by direct multisegmental nSCA, subsets of which express TRPV1 in Lissauer's tract and the dorsal column. J. Comp. Neurol. 521:2870-2887, 2013. © 2013 Wiley Periodicals, Inc.

Immunohistochemical characterization of neurons and neuronal processes in the dorsal vagal nucleus of the pig

The vagus nerve is responsible for efferent and afferent innervation of the gastrointestinal tract. The efferent fibres originate from neurons located in the dorsal motor nucleus of the vagus (DMX) and control mainly the gastric motor and secretory function. The main goal of our study was to examine expression of ChAT, SP, LENK, NOS and CART in the neuronal matrix of the porcine DMX. Double-labeling immunofluorescence revealed plenty of ChAT-IR neuronal cell bodies and fibres distributed throughout the nuclear matrix. Between the cholinergic somata and processes numerous SP-, LENK- and CART-IR neuronal protrusions forming dense networks were identified. While net of the NOS-IR fibres presented moderate density, the SP- and LENK-IR processes were often observed to form a basket-like structure closely surrounding the cholinergic parasympathetic neurons. Individual CART-IR basket-like formations were also encountered. A few double labeled ChAT-/NOS-IR perikarya in the rostral segment of the nucleus were also found. We confirm expression of studied antigens in the porcine DMX and provide morphological foundations for a possible regulatory role of SP, LENK, NOS and CART in porcine vago-visceral signaling.

Level Diagnosis of Cervical Compressive Myelopathy: Signs, Symptoms, and Lesions Levels

Background: To elucidate signs and symptoms corresponding to each vertebral level for level-specific diagnoses. Methods: We studied 106 patients with cervical compressive myelopathy. Patients who showed a single compressive site on magnetic resonance imaging ( MRI ) were selected, and signs, symptoms, and the levels of the MRI lesions were studied. Results: Five of 12 patients (41.7%) with C4-5 intervertebral level lesions showed decreased or absent biceps and brachioradialis reflexes, while 4 of these patients (33.3%) showed generalized hyperreflexia. In comparison, 5 of 24 patients (20.8%) with C5-6 intervertebral level lesions showed decreased or absent triceps reflexes; however, 9 of these patients (37.5%) showed decreased or absent biceps and brachioradialis reflexes. Conclusions: C4-5 intervertebral level lesions not only showed C6 segment signs but also showed more rostral segment signs. Similarly, C5-6 intervertebral level lesions not only showed C7 segment signs but also showed C6 or more rostral segment signs. J Neurol Res. 2013;3(5):135-141 doi: https://doi.org/10.4021/jnr236w

Spinal Transection Induces Widespread Proliferation of Cells along the Length of the Spinal Cord in a Weakly Electric Fish

The ability to regenerate spinal cord tissue after tail amputation has been well studied in several species of teleost fish. The present study examined the proliferation and survival of cells following complete spinal cord transection rather than tail amputation in the weakly electric fish Apteronotus leptorhynchus. To quantify cell proliferation along the length of the spinal cord, fish were given a single bromodeoxyuridine (BrdU) injection immediately after spinal transection or sham surgery. Spinal transection significantly increased the density of BrdU⁺ cells along the entire length of the spinal cord at 1 day posttransection (dpt), and most newly generated cells survived up to 14 dpt. To examine longer-term survival of the newly proliferated cells, BrdU was injected for 5 days after the surgery, and fish were sacrificed at 14 or 30 dpt. Spinal transection significantly increased cell proliferation and/or survival, as indicated by an elevated density of BrdU⁺ cells in the spinal cords of spinally transected compared to sham-operated and intact fish. At 14 dpt, BrdU⁺ cells were abundant at all levels of the spinal cord. By 30 dpt, the density of BrdU⁺ cells had decreased at all levels of the spinal cord except at the tip of the tail. Thus, newly generated cells in the caudal-most segment of the spinal cord survived longer than those in more rostral segments. Our findings indicate that spinal cord transection stimulates widespread cellular proliferation; however, there were regional differences in the survival of the newly generated cells.

Distributions of active spinal cord neurons during swimming and scratching motor patterns

The spinal cord can generate motor patterns underlying several kinds of limb movements. Many spinal interneurons are multifunctional, contributing to multiple limb movements, but others are specialized. It is unclear whether anatomical distributions of activated neurons differ for different limb movements. We examined distributions of activated neurons for locomotion and scratching using an activity-dependent dye. Adult turtles were stimulated to generate repeatedly forward swimming, rostral scratching, pocket scratching, or caudal scratching motor patterns, while sulforhodamine 101 was applied to the spinal cord. Sulforhodamine-labeled neurons were widely distributed rostrocaudally, dorsoventrally, and mediolaterally after each motor pattern, concentrated bilaterally in the deep dorsal horn, the lateral intermediate zone, and the dorsal to middle ventral horn. Labeled neurons were common in all hindlimb enlargement segments and the pre-enlargement segment following swimming and scratching, but a significantly higher percentage were in the rostral segments following swimming than rostral scratching. These findings suggest that largely the same spinal regions are activated during swimming and scratching, but there are some differences that may indicate locations of behaviorally specialized neurons. Finally, the substantial inter-animal variability following a single kind of motor pattern may indicate that essentially the same motor output is generated by anatomically variable networks.