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Sacral spinal cord ependymoma is an uncommon pathology. Most of the reported cases are consistent with a myxopapillary ependymoma histopathologic subtype. Non-myxopapillary ependymomas rarely occur in the sacral region. Most lesions are intradural; however, rare extradural cases can occur. We present the case of a 46-year-old female patient diagnosed with a grade II sacral extradural ependymoma, emphasising the importance of an interdepartmental case approach for diagnosis and management. Even though grade II ependymomas are considered low grade, the potential for recurrence and metastatic disease has been reported. There are no treatment guidelines for these rare tumours besides gross total resection.

Storage and voiding of urine from the lower urinary tract (LUT) must be timed precisely to occur in appropriate behavioral contexts. A major part of the CNS circuit that coordinates this activity is found in the lumbosacral spinal cord. Immediate early gene (IEG) activity mapping has been widely used to investigate the lumbosacral LUT‐related circuit, but most reports focus on the effects of noxious stimulation in anesthetized female rats. Here we use c‐Fos and EGR‐1 (Zif268) activity mapping of lumbosacral spinal cord to investigate cystometry‐induced micturition in awake female and male rats. In females, after cystometry c‐Fos neurons in spinal cord segments L5–S2 were concentrated in the sacral parasympathetic nucleus (SPN), dorsal horn laminae II–IV, and dorsal commissural nucleus (SDCom). Comparisons of cystometry and control groups in male and female revealed sex differences. Activity mapping suggested dorsal horn laminae II–IV was activated in females but showed net inhibition in males. However, inhibition in male rats was not detected by EGR‐1 activity mapping, which showed low coexpression with c‐Fos. A class of catecholamine neurons in SPN and SDCom neurons were also more strongly activated by micturition in females. In both sexes, most c‐Fos neurons were identified as excitatory by their absence of Pax2 expression. In conclusion, IEG mapping in awake male and female rats has extended our understanding of the functional molecular anatomy of the LUT‐related circuit in spinal cord. Using this approach, we have identified sex differences that were not detected by previous studies in anesthetized rats., A major part of the circuit that coordinates bladder voiding is found in the lumbosacral spinal cord. Here we use c‐Fos and EGR‐1 (Zif268) activity mapping of lumbosacral spinal cord to investigate cystometry‐induced micturition in awake female and male rats. In both sexes, most c‐Fos neurons were identified as excitatory by their absence of Pax2 expression. Using this approach, we have identified sex differences that were not detected by previous studies in anesthetized rats.

NADPH diaphorase (N-d) neurons distribute in spinal cord and function for visceral sensation and autonomic regulation. N-d positive neurons innervate pelvic organs. In previous investigation, we report that aging-related N-d body (ANB) in the lumbosacral spinal cord in aged rat and megaloneurite in the sacral spinal cord in aged dog. This article was a continued data report of aging-related N-d alterations in aged dog. N-d positivity in aged spinal cord has revealed a certain of morphological profiles in the spinal cord of several species. However, we still found some denoted N-d neurodegenerative changes that we failed to notice in our previous studies when re-examination of the sacral spinal cord of aged dog. In the horizontal section, spacing spheroids in the superficial laminae of the dorsal horn, curl-up and coiled neurites in the intermediate zone were detected in the sacral spinal cord. The ANB and vacuolar neurite were also detected. Vacuolar degeneration also occurred in the dorsal ganglia at the sacral segment. The curl-up and coiled neurites did not occur in the lumbothoracic segment, but the ANB and vacuolar neurite were scatteringly detected in in the lumbothoracic segment of aged dog. The results suggested that the N-d sensory inputs interrupted and disconnected with integration of autonomic centers and output circuits of regulating urogenital organs during the aging. These specialized profiles were speculated that the N-d neurite deterioration of visceral sensory circuit implicated dysfunction of pelvic organs in the aging. Megaloneurite and fiber dilation may make backward reasoning to N-d fiber architecture under normal condition.

Although anatomical studies have indicated pudendal motoneurons to give off recurrent collaterals, they are not considered to make synapses onto interneurons, such as Renshaw cells, and rather terminate their own signals. No study till date has examined interneurons being driven by recurrent collaterals of pudendal motoneurons. Here, we aimed to investigate the existence of Renshaw cells driven by pudendal motoneurons along with the recurrent inhibition of the latter. Extracellular recordings were obtained from the ventral horn of the sacral spinal cord of anesthetized cats. Dorsal roots were sectioned, and motor axons were electrically stimulated. Renshaw-like cells driven by recurrent collaterals, with high-frequency firings at short latency discharge, were observed around Onuf’s nucleus. However, the recurrent inhibitory post-synaptic potentials were not recorded by intracellular recordings from the pudendal motoneurons. In summary, we found Renshaw-like cells driven by pudendal motoneurons, but we could not identify the synaptic connection of these neurons.

There are several methods for determining the remaining function of the sacral spinal cord following a spinal cord injury. Two of these methods are the bulbocavernosus and the anal wink reflexes. The choice of which reflex to use should be determined by the need for clinical information. These two reflexes provide similar information; however, they may have different prognostic value.

Sensorimotor circuits of the lumbosacral spinal cord are required for lower urinary tract (LUT) regulation as well as being engaged in pelvic pain states. To date, no molecular markers have been identified to enable specific visualization of LUT afferents, which are embedded within spinal cord segments that also subserve somatic functions. Moreover, previous studies have not fully investigated the patterning within or across spinal segments, compared afferent innervation of the bladder and urethra, or explored possible structural sex differences in these pathways. We have addressed these questions in adult Sprague-Dawley rats, using intramural microinjection of the tract tracer, cholera toxin B subunit. Afferent distribution was analysed within individual sections and 3D reconstructions from sections across four spinal cord segments (L5-S2), and in cleared intact spinal cord viewed with light sheet microscopy. Simultaneous mapping of preganglionic neurons showed their location throughout S1 but restricted to the caudal half of L6. Afferents from both LUT regions extended from L5 to S2, even where preganglionic motor pathways were absent. In L6 and S1, most afferents were associated with the sacral preganglionic nucleus and sacral dorsal commissural nucleus, with very few in the superficial laminae of the dorsal horn. Spinal innervation patterns by bladder and urethra afferents were remarkably similar, likewise the patterning in male and female rats. In conclusion, micro- to macro-scale mapping has identified distinct features of LUT afferent projections to the lumbosacral cord and provided a new anatomical approach for future studies on plasticity, injury responses and modelling of these pathways.Significance statementIn this multi-scale neuroanatomical study, we have developed novel maps of bladder and urethra afferent pathways in the spinal cord of male and female rats. Afferents visualised by transganglionic tracing were registered to anatomical landmarks including motoneuron pools and preganglionic autonomic neurons, enabling comparisons across animals and specific regions of the cord. We integrated data from 3D reconstructions of sections, light sheet microscopy of cleared, contiguous spinal segments and confocal microscopy to assess connectivity at microscale. In addition to providing new understanding of lumbosacral visceral circuitry, this dataset provides the foundation for future studies on plasticity and regenerative capacity of these circuits, changes during the life cycle and parameters for modelling spinal circuits relevant to lower urinary tract function.

BackgroundNerve excitability tests in sciatic motor axons are sensitive to anaesthetic choice. Results using ketamine/xylazine (KX) are different from those using sodium pentobarbital (SP). It is not clear which results are most similar to the awake condition, though results using SP appear more similar to human results.MethodsNerve excitability in tail motor axons was tested in 8 adult female rats with a chronic sacral spinal cord injury. These animals have no behavioural response to electrical stimulation of the tail and were tested awake and then anaesthetized using SP.ResultsThe nerve excitability test results in the awake condition were indistinguishable from the results when the same rats were anaesthetized with sodium pentobarbital. Summary plots of the test results overlap within the boundaries of the standard error and paired t-tests on the 42 discrete measures generated by nerve excitability testing yielded no significant differences (after Bonferroni correction for multiple comparisons).ConclusionsNerve excitability test results in rat motor axons are the same whether the animals are awake or anesthetized using sodium pentobarbital.

NADPH diaphorase (NADPH-d) was used to detected neurodegeneration in animal models. In our previous studies, aging-related NADPH-d positive spheroidal bodies (ANB) occurred in the lumbosacral spinal cord of aged rats. Recently, NADPH-d enlarged-diameter neurites named as megaloneurites were detected in the sacral spinal cord of aged dogs. To generalize the occurrence of megaloneurites and/or ANB in non-human primates, the advanced examination of the aging-related phenotypes was undertaken in the monkeys by using the same approach. We discovered two different anomalous NADPH-d positive alterations, which were expressed as ANB and megaloneurites specially distributed in the superficial dorsal horn, dorsal gray commissure, lateral collateral pathway (LCP) and sacral parasympathetic nucleus in the aged monkeys’ sacral spinal cord, compared with the cervical, thoracic and lumbar segments. In the gracile nucleus of aged monkeys, only aging-related spheroidal bodies were observed and no megaloneurites occurred. The dense, abnormal NADPH-d positive megaloneurites, extremely different from regular NADPH-d positive fibers, were prominent in the sacral segments and occurred in extending from Lissauer’s tract through lamina I along the lateral boundary of the dorsal horn to the region of the SPN. Meanwhile, large diameter punctate NADPH-d activity occurred and scattered in the lateral white matter of the LCP and dorsal root entry zone at the same level of NADPH-d abnormality in the gray matters. Those dot-like NADPH-d alterations were examined by horizontal sectioning and indicated ascending or descending oriental fibers. These NADPH-d megaloneurites had the same composition as the punctate NADPH-d alterations and were co-localized with the vasoactive intestinal peptide (VIP) immunoreaction, while the ANB did not coexist with the VIP immunoreaction. Both ANBs and megaloneurites provide consistent evidence that the anomalous neuritic alterations in the aged sacral spinal cord are referred to as a specialized aging marker in the pelvic visceral organs in non-human primates.

Spinal cord injury (SCI) is characterized by multiple sensory/motor impairments that arise from different underlying neural mechanisms. Linking specific sensory/motor impairments to neural mechanism is limited by a lack of direct experimental access to these neural circuits. Here, we describe an experimental model which addresses this shortcoming. We generated a mouse model of chronic spinal cord injury that reliably reproduces spasticity observed after SCI, while at the same time allows study of motor impairments in vivo and in an in vitro preparation of the spinal cord. The model allows for the combination of mouse genetics in in vitro and in vivo conditions with advanced imaging, behavioral analysis, and detailed electrophysiology, techniques which are not easily applied in conventional SCI models.

Control of pelvic floor muscles (PFM) is regulated by somatic afferent and efferent nerves from the sacral spinal cord; these are integrated at the spinal cord and brain stem levels which in turn are heavily influenced by inputs from higher cortical levels. These cortical influences modulate reflex activity and also govern voluntary activity, which is important for socially adapted behavior related to urinary, anorectal, and sexual functions.

Summary This study aimed to explore the effects of intracavernous injection (ICI) of P2X3 and NK1 receptor antagonists on erectile dysfunction (ED) induced by spinal cord transection in rats. Sixty male Sprague–Dawley (SD) rats were randomly divided into the following three groups (20 rats each group): sham operation group (C group), thoracic spinal cord transection group (T group) and sacral spinal cord transection group (S group). An ED model was established through complete transection of the thoracic or sacral spinal cord. Intracavernous pressure (ICP) with and without injection of P2X3 (Suramin) or NK1 (GR82334) receptor antagonists was recorded 3 weeks after surgery. Immunohistochemistry was employed to detect the expression of P2X3 and NK1 receptors in the dorsal root ganglion (DRG) and smooth muscle of corpus cavernosum. Data were processed with SPSS 17.0. ICI with Suramin (0.1, 0.3 and 1 mm) or GR82334 (0.1, 0.3 and 1 mm) increased ICP dose dependently in the T and S groups. The expression of P2X3 and NK1 receptors in DRG and smooth muscle of corpus cavernosum was up-regulated in the T and S groups. It is concluded that ICI of P2X3 and NK1 receptor antagonists may improve the recovery of erectile function in a rat model with ED after spinal cord transection.

The clinical findings in four cases of radiation injury to the lumbosacral spinal cord and cauda equina, occurring after radiotherapy of malignant testicular tumours with radiation doses of 1597–1670 ret, are reported. The main feature in each case was a flaccid paraparesis, without sensory loss in three cases, while one patient presented a doubtful sensory deficit. Symptoms of sphincter dysfunction were absent. In all cases the symptoms caused a marked and persistent incapacity. It is suggested that the principal site of radiation injury is the proximal parts of the lower motor neuron.

BACKGROUND AND PURPOSE: Recent literature indicates that cervical and upper-thoracic spinal cord motion adversely affect both structural and functional MR imaging (fMRI; particularly diffusion tensor imaging [DTI] and spinal fMRI), ultimately reducing the reliability of these methods for both research and clinical applications. In the present study, we investigated motion of the lower-thoracic, lumbar, and sacral cord segments to evaluate the incidence of similar motion-related confounds in these regions. MATERIALS AND METHODS: Recently developed methods, used previously for measuring cervical and upper-thoracic spinal cord motion, were employed in the present study to examine anteroposterior (A/P) and left-right (L/R) spinal cord motion in caudal regions. Segmented cinematic imaging was applied with a gradient-echo, turbo fast low-angle shot (turbo-FLASH) pulse sequence to acquire midline images of the cord at 24 cardiac phases throughout the lower-thoracic, lumbar, and sacral spinal cord regions. RESULTS: The magnitude of A/P motion was found to be largest in rostral cord regions, whereas in caudal regions (at the level of the T4/T5 vertebrae and below), peak cord motion was uniformly small (routinely ≤0.10 mm). L/R motion, however, was found to be minimal throughout the thoracic, lumbar, and sacral regions. CONCLUSION: Motion-related errors in spinal fMRI and DTI are expected to be significantly reduced throughout caudal regions of the spinal cord, thus yielding higher sensitivity and specificity compared with rostral regions. The paucity of such errors is expected to provide a means of observing the specific impact of motion (in rostral regions) and to enable the acquisition of uncorrupted DTI and fMRI data for studies of structure and function throughout lumbar and sacral regions.

We present a case of a 44-year-old woman with an unusual location of a brown tumor in the sacral vertebrae due to parathyroid adenoma. She was admitted to our clinic with the complaint of low-back pain and was later diagnosed to have a brown tumor. The patient underwent surgery and partial sacrectomy and iliac wing resection was performed in Orthopedic Surgery Department. Subsequently the patient underwent parathyroid adenoma excision in General Surgery Department. On her control examination at postoperative 3 months, she had no pain and was able to perform daily activities without any problem. We believe it is an interesting clinical case both because it shows a very rare localization of brown tumor and points out the importance of employing a wide clinical scope in the differential diagnosis of back pain.

GDNF (glial cell line-derived neurotrophic factor), neurturin and artemin use their co-receptors (GFRα1, GFRα2 and GFRα3, respectively) and the tyrosine kinase Ret for downstream signalling. In rodent dorsal root ganglia (DRG) most of the unmyelinated and some myelinated sensory afferents express at least one GFRα. The adult function of these receptors is not completely elucidated but their activity after peripheral nerve injury can facilitate peripheral and central axonal regeneration, recovery of sensation, and sensory hypersensitivity that contributes to pain. Our previous immunohistochemical studies of spinal cord and sciatic nerve injuries in adult rodents have identified characteristic changes in GFRα1, GFRα2 or GFRα3 in central spinal cord axons of sensory neurons located in dorsal root ganglia. Here we extend and contrast this analysis by studying injuries of the pelvic and hypogastric nerves that contain the majority of sensory axons projecting to the pelvic viscera (e.g., bladder and lower bowel). At 7 d, we detected some effects of pelvic but not hypogastric nerve transection on the ipsilateral spinal cord. In sacral (L6-S1) cord ipsilateral to nerve injury, GFRα1-immunoreactivity (IR) was increased in medial dorsal horn and CGRP-IR was decreased in lateral dorsal horn. Pelvic nerve injury also upregulated GFRα1- and GFRα3-IR terminals and GFRα1-IR neuronal cell bodies in the sacral parasympathetic nucleus that provides the spinal parasympathetic preganglionic output to the pelvic nerve. This evidence suggests peripheral axotomy has different effects on somatic and visceral sensory input to the spinal cord, and identifies sensory-autonomic interactions as a possible site of post-injury regulation.

There have been previous reports of both demographic and clinical features with urodynamic evaluation results of patients with traumatic spinal cord injury (SCI). These studies were conducted on patients with cervical and thoracal SCI, but there has been no comparative study evaluating the urodynamic outcomes of patients with lumbosacral SCI. Therefore, it was aimed to investigate the bladder features and treatment options in patients with lumbosacral SCI to be able to take appropriate therapeutic decisions. The urodynamic data of 121 patients with lumbar and sacral SCI were obtained retrospectively using the urodynamics unit records. The patients were grouped as upper lumbar (L1 and L2) SCI (ULSCI) and lower lumbar–sacral (L3 to S5) SCI (LLSSCI). The patients were 92 males (76 %) and 29 (24 %) females, comprising 74 (61.2 %) ULSCI patients and 47 (38.8 %) LLSSCI patients. Detrusor hypocompliancy and anticholinergic prescription were more frequent in the ULSCI group than in the LLSSCI group, while alpha-blocker prescription was more frequent in the LLSSCI group than in the ULSCI group. There was a statistically significant difference between the groups in respect of the rates of bladder-emptying method on admission. A higher mean micturated urine volume was observed in the LLSSCI group than in the ULSCI group. The rates of bladder-filling sensation, detrusor overactivity, bladder–storage and emptying disorders, prescribed emptying method, and residual urine volume were similar in both groups. These results showed that there are differences in neurogenic bladder features and treatment options for patients with upper lumbar and lower lumbar–sacral SCI.

The bladder has two functions: to store urine and to periodically void the contents. The lower urinary tract has two components that must act in a coordinated way to achieve these functions: the urinary bladder and a competent sphincter mechanism. Urine storage is possible when the bladder is relaxed and compliant, and the sphincter offers a high resistance. Voiding occurs when the sphincter relaxes, and the bladder contracts to raise intravesical pressure. Urodynamics can illustrate these changes of function. Control of this coordinated system is mediated by a nervous pathway involving pontine centres that in turn exert control over a sacral reflex. The periaqueductal grey and pontine micturition centre play key roles in this central nervous control. Efferent control is achieved via autonomic and somatic pathways from the sacral spinal cord to the bladder and sphincter. Incontinence occurs when the system is deranged and may be due to bladder overactivity, sphincter dysfunction or bladder underactivity. There are many causes of these dysfunctions and drug management offers solutions in some cases.

The authors believe that the principles underlying the multiple possible SNS mechanisms of action can be summarized as somatic afferent inhibition of sensory processing in the spinal cord. Regardless of whether the lower urinary tract dysfunction involves storage versus emptying abnormalities, the pudendal afferent signaling serves as a common crossroads in the neurologic wiring of the system. Not only can pudendal afferent input turn on voiding reflexes by sup-pressing the guarding reflex pathways, pudendal afferent input to the sacral spinal cord also can turn off supraspinally mediated hyperactive voiding by blocking ascending sensory pathway inputs. For these reasons, SNS can take advantage of the complex neurologic pathways described and offer successful treatment for a seemingly disparate group of lower urinary tract pathologies. SNS is a urologic technique that has proved safe and minimally invasive, and it holds great promise for many patients who have lower urinary tract dysfunction.

Superior hypogastric plexus block has been advocated for the treatment of cancer related pelvic pain. Neurolysis is usually established using the classical posterolateral approach in the prone position, in which correct placement of the needle is sometimes difficult due to vertebral anatomy and the patient's inability to lie prone. We describe an alternative posteromedian transdiscal approach under fluoroscopic guidance for the treatment of intractable pelvic pain in three patients, in whom the classical approach was not possible. The L5-S1 inter-discal space was identified with fluoroscopy. The needle was then introduced through the disc and advanced under lateral fluoroscopic control. After verifying correct needle placement, neurolysis was performed with 8 ml of 10% phenol solution. All patients had significant pain relief immediately after the block, lasting from 6 to 12 months, and their pain severity scores and opioid consumption were reduced by more than 50%. There were no complications such as discitis, disc rupture or nerve injury. Since this new posteromedian transdiscal approach provides easy access to the superior hypogastric plexus with a single puncture and with any patient position, it may be an alternative to the classical approach.

Stress urinary incontinence (SUI) is the accidental leakage of urine associated with physical activities such as running, jumping or lifting or with sneezing and coughing. For many patients it can be a very bothersome symptom, causing social isolation, loss of self-esteem and increased financial outlays. Although there is currently no medication approved worldwide for the treatment of SUI, a variety of off-label agents are sometimes prescribed. Duloxetine (LY-248686; Eli Lilly), a new centrally acting compound with dual activity as a serotonin and noradrenaline re-uptake inhibitor, offers a promising new approach for treatment. Due to its inhibition of presynaptic neuron re-uptake of serotonin and noradrenaline in the sacral spinal cord, duloxetine is believed to increase the strength of urethral sphincter contractions and thereby prevent accidental urine leakage by increasing urethral closure pressure. In three published trials in women with the predominant symptom of SUI, duloxetine significantly reduced the number of incontinence episodes compared to placebo. Adverse events were usually observed early in treatment, were mild-to-moderate in severity and were transient. Nausea was the most common reason for discontinuation.

Motor units of segmental tail muscles were recorded in awake rats following acute (1–2 days) and chronic (>30 days) sacral spinal cord transection to determine whether plateau potentials contributed to sustained motor-unit discharges after injury. This study was motivated by a companion in vitro study that indicated that after chronic spinal cord injury, the tail motoneurons of the sacrocaudal spinal cord exhibit persistent inward currents ( I PIC) that cause intrinsically sustained depolarizations ( plateau potentials) and firing ( self-sustained firing). Importantly, in this companion study, the plateaus were fully activated at recruitment and subsequently helped sustain the firing without causing abrupt nonlinearities in firing. That is, after recruitment and plateau activation, the firing rate was modulated relatively linearly with injected current and therefore provided a good approximation of the input to the motoneuron despite the plateau. Thus in the present study, pairs of motor units were recorded simultaneously from the same muscle, and the firing rate ( F) of the lowest-threshold unit (control unit) was used as an estimate of the synaptic input to both units. We then examined whether firing of the higher-threshold unit (test unit) was intrinsically maintained by a plateau, by determining whether more synaptic input was required to recruit the test unit than to maintain its firing. The difference in the estimated synaptic input at recruitment and de-recruitment of the test unit (i.e., change in control unit rate, Δ F) was taken as an estimate of the plateau current ( I PIC) that intrinsically sustained the firing. Slowly graded manual skin stimulation was used to recruit and then de-recruit the units. The test unit was recruited when the control unit rate was on average 17.8 and 18.9 Hz in acute and chronic spinal rats, respectively. In chronic spinal rats, the test unit was de-recruited when the control unit rate (re: estimated synaptic input) was significantly reduced, compared with at recruitment (Δ F = −5.5 Hz), and thus a plateau participated in maintaining the firing. In the lowest-threshold motor units, even a brief stimulation triggered very long-lasting firing (seconds to hours; self-sustained firing). Higher-threshold units required continuous stimulation (or a spontaneous spasm) to cause firing, but again more synaptic input was needed to recruit the unit than to maintain its firing (i.e., plateau present). In contrast, in acute spinal rats, the stimulation did not usually trigger sustained motor-unit firing that could be attributed to plateaus because Δ F was not significantly different from zero. These results indicate that plateaus play an important role in sustaining motor-unit firing in awake chronic spinal rats and thus contribute to the hyperreflexia and hypertonus associated with chronic injury.

Quantitative analyses were performed on the dendrites and somata of 25 electrophysiologically identified preganglionic neurons (PGN) obtained from the sacral spinal cord of the cat by intracellular injection of Neurobiotin or horseradish peroxidase. Total dendritic length and surface area were measured for each dendrite. The sizes of the stem dendrites measured at their base were positively correlated with the sizes of the entire tree and numbers of end branches. Total surface area of somata and dendrites averaged 39,138 μm2; 90.7% of that was from the dendrites. To obtain measurements of the relative contributions of PGN dendrites to specific regions of the spinal cord, the percentage of each dendrite occupying eight spinal cord regions was recorded. Sixty-three percent of the dendrites projected dorsal to their somata, whereas an average of 33.3% of dendrites were located in the white matter, most of them in the lateral and dorsolateral funiculi. The neurons within this sample formed a continuum with some neurons having a large percentage of dendrites in lamina I but little in the white matter, whereas at the other end of the continuum were cells with the reverse configuration. The intermediate neurons had dendrites in both locations. Taken together, these data indicate a heterogeneous population of PGN in the lateral band of the sacral parasympathetic nucleus. J. Comp. Neurol. 437:56–69, 2001. © 2001 Wiley-Liss, Inc.

1. The aim of the present study is to map the incipient phase of Fos expression in the sacral spinal cord neuronal pools of multiple cauda equina constrictions canine model. 2. Fos-positive neurons were found bilaterally in the lateral portion of superficial dorsal horn layers (Laminae I–III) and along the lateral edge of the dorsal horn accompanied by the lateral collateral pathway, fibers of Lissauer's tract, terminating at the sacral parasympathetic nucleus. Similarly, high Fos expression was detected in the ventral portion of the dorsal sacral commissure and in the dorsomedial portion of the anterior horns at S1–S3 segment level. Finally, a clearly expressed Fos-positivity was disclosed bilaterally in the neuropil of the nucleus Y in the anterior horn. 3. Data from the present study show that continuous stimulation of the central fibers of sacral dorsal root ganglia neurons, i.e., fibers of sacral primary afferents, unlike those using various stimulations of the peripheral fibres offers an unusual pattern of Fos-like immunoreactivity.

Unmyelinated sensory axons in the sacral spinal cord may play a role in bladder reflexes under certain pathological conditions. Previous data suggested vasoactive intestinal polypeptide (VIP) might be contained exclusively in sensory C-fibers, some of which innervate the bladder. This study was undertaken to describe the morphology of these VIP fibers in the sacral cord of the cat. VIP immunoreactivity was confined to unmyelinated axons observed at several levels of the sensory pathway including the dorsal root ganglia, dorsal roots, Lissauer's tract, and the lateral collateral pathway. A combination of light and electron microscopic observations showed VIP-immunoreactive fibers with labeled varicosities and synaptic terminals in laminae I, IIo, V, VII, and X. VIP-immunolabeled varicosities had a mean diameter of 1.6 microm (range = 0.11-7.4 microm, S.D. = 1.01, n = 311) with a small percentage (8%) being relatively large (3-7.4 microm). VIP varicosities contained a mixture of small clear vesicles (CLV) and large dense core vesicles (LDV). Although most varicosities contained a moderate number of LDVs (14.86 LDVs/microm2), some varicosities contained a large number of LDVs, whereas others contained very few. Varicosities that possessed synaptic specializations were classed as terminals and were divided into three morphological classes. Two of these resembled Gray's Type I terminal, whereas a third was similar to the Gray's Type II terminal. There was no consistent relationship between vesicle content of the terminal and the type of synaptic contact it possessed. This study shows that in the sacral spinal cord of the cat, VIP terminals originate only from C-fibers, terminate primarily in laminae I and V, and exhibit a variety of morphologies consistent with heterogeneous origins and functions of the lower urinary tract.

A gelatinous focus with cystic spaces, was found in the posterior funiculus of the 2nd to 3rd lumbar levels of the spinal cord of a Japanese Black heifer, 2 years old, with clinical signs of severe dysstasia. Histopathological examination revealed that the spinal lesion consisted of multifocal and diffuse proliferation of round cells with abundant vacuolar cytoplasm and hyperchromatic nuclei. In the lesions there was a number of cystic spaces containing aggregates of small round cells. The neoplastic foci showed a honeycomb structure divided by thin blood vessels, representing typical lesions of oligodendroglioma. Diffuse and multifocal proliferation of these round cells were also recognized in the subarachnoidal space in the sacral spinal cord. Immunohistochemically, the proliferating round cells were negative for glial fibrillary acidic protein. Based on these morphological features, the case was diagnosed as lumbar spinal oligodendroglioma with diffuse arachnoidal dissemination.

The sacral neural pathways mediating penile erection in the cat were studied by measuring the change in cavernous sinus pressure (CSP) elicited by stimulation of the sacral ventral roots or by microstimulation of the sacral spinal cord. Ventral root stimulation revealed that the S1 segment rather than S2 and S3 spinal segments could evoke the largest CSP responses. Microstimulation in the S1 spinal cord elicited large CSP responses but small or no bladder contractions. Maximal CSP responses were evoked by microstimulation in the middle of the S1 ventral horn, 1.6-2.8 mm below the cord surface and midway between the midline and the lateral edge of the gray matter. The area was 200-400 microm wide (medial to lateral) and extended 1-2 mm in the rostrocaudal direction. Maximal CSP responses to spinal cord microstimulation were elicited by stimulus intensities of 50-150 microA, at a pulse width of 0.2 ms and at frequencies of 3040 Hz and occurred after delay of 8-40 s. This study suggests that focal microstimulation of the sacral spinal cord might be useful in eliciting penile erectile activity in patients with spinal cord injury.

1. A goal of this study was to determine whether neurons in the sacral spinal cord that project to the diencephalon are involved in the processing and transmission of sensory information that arises in the perineum and pelvis. Therefore, 58 neurons in segments L6-S2 were activated antidromically with currents < or = 30 microA from points in the contralateral diencephalon in rats that were anesthetized with urethan. 2. Responses to mechanical stimuli applied to the cutaneous receptive fields of these neurons were used to classify them as low-threshold (LT), wide dynamic range (WDR) or high-threshold (HT) neurons. Twenty-two neurons (38%) responded preferentially to brushing (LT neurons). Eighteen neurons (31%) responded to brushing but responded with higher firing frequencies to noxious mechanical stimuli (WDR neurons). Eighteen neurons (31%) responded only to noxious intensities of mechanical stimulation (HT neurons). LT neurons were recorded predominantly in nucleus proprius of the dorsal horn. Nociceptive neurons (WDR and HT) were recorded throughout the dorsal horn. 3. Cutaneous receptive fields were mapped for 56 neurons. Forty-five (80%) had receptive fields that included at least two of the following regions ipsilaterally: the rump, perineum, or tail. Eleven neurons (20%) had receptive fields that were restricted to one of these areas or to the ipsilateral hind limb. Thirty-eight neurons (68%) had cutaneous receptive fields that also included regions of the contralateral tail or perineum. On the perineum, receptive fields usually encompassed perianal and perivaginal areas including the clitoral sheath. There were no statistically significant differences in the locations or sizes of receptive fields for LT neurons compared with nociceptive (WDR and HT) neurons. 4. Thirty-seven LT, WDR, and HT neurons were tested for their responsiveness to heat stimuli. Five (14%) responded to increasing intensities of heat with graded increases in their firing frequencies. Thirty-two LT, WDR, and HT neurons also were tested with cold stimuli. None responded with graded increases in their firing frequencies to increasingly colder stimuli. There were no statistically significant differences among the responses of LT, WDR, and HT neurons to either heat or cold stimuli. 5. Forty LT, WDR, and HT neurons were tested for their responsiveness to visceral stimuli by distending a balloon placed into the rectum and colon with a series of increasing pressures. Seventeen (43%) exhibited graded increases in their firing frequencies in response to increasing pressures of colorectal distention (CrD). None of the responsive neurons responded reproducibly to CrD at an intensity of 20 mmHg, and all responded at intensities of > or = 80 mmHg. More than 90% responded abruptly at stimulus onset, responded continuously throughout the stimulus period, and stopped responding immediately after termination of the stimulus. 6. Thirty-one neurons were tested for their responsiveness to distention of a balloon placed inside the vagina. Eleven (35%) exhibited graded increases in their firing frequencies in response to increasing pressures of vaginal distention (VaD). The thresholds and temporal profiles of the responses to VaD were similar to those for CrD. Twenty-nine neurons were tested with both CrD and VaD. Thirteen (45%) were excited by both stimuli, four (14%) responded to CrD but not VaD, and one (3%) was excited by VaD but not CrD. Neurons excited by CrD, VaD, or both were recorded throughout the dorsal horn. 7. As a population, WDR neurons, but not LT or HT neurons, encoded increasing pressures of CrD and VaD with graded increases in their firing frequencies. The responses of WDR neurons to CrD differed significantly from those of either LT or HT neurons. Regression analyses of the stimulus-response functions of responsive WDR neurons to CrD and VaD were described by power functions with exponents of 1.6 and 2.4, respectively.(ABSTRACT TRUNCATED)

Aims Beta3-adrenoceptor selective agonists are evaluated as a new treatment for patients with lower urinary tract symptoms . It is believed that β3-AR selective agonists exert their effects via a peripheral site of action. However, β3-ARs have been found in brain tissue. This study examined whether β3-ARs are present in rat sacral spinal cord, and whether there are differences in β3-AR expression between normal and partial urethral obstruction (PUO) animals, and furthermore assessed the functional relevance of spinal β3-ARs for micturition. Methods Thirty-eight male Sprague–Dawley rats underwent either PUO or sham-operation. Two weeks after operation, half of the animals were used for histomorphological analysis. Remaining animals were used for functional experiments, where a β3-AR selective agonist, BRL 37344, was given intrathecally. Bladder function was assessed by continuous cystometry in non-anesthetized animals before and after drug administration. Results Beta3-ARs were found in sacral spinal cord segments with an accumulation in the ventral horn. There was a significant increase of β3-AR expression in obstructed rats. In functional experiments obstructed rats showed increased bladder weight, micturition frequency, spontaneous activity, and bladder pressures (all P

This chapter focuses on localization of motoneurons in the spinal. The motoneurons in the spinal cord belong to two functional groups: somatic and visceral. Somatic motoneurons innervate skeletal or voluntary muscle while visceral (autonomic) motoneurons innervate smooth muscle and glands. Somatic motoneurons are located in the ventral horn of the gray of the spinal cord and innervate the striated muscles of the axial skeleton (neck and trunk) and the muscles of the upper and lower limbs. The majority of somatic motoneurons are alpha motoneurons innervating the extrafusal muscle fibers within skeletal muscle. A smaller proportion of these motoneurons, the gamma motoneurons, innervate the intrafusal muscle fibers within muscle spindles. Autonomic motoneurons are located in the intermediate horn of the spinal cord between the dorsal and ventral horns. These motoneurons are further subdivided into two functional groups, sympathetic and parasympathetic. Sympathetic preganglionic motoneurons are located in the thoracic and upper lumbar parts of the spinal cord; they provide a vasodilator innervation to smooth muscle of the blood vessels both within viscera and to the tissues, innervation to the sweat glands, to the arrector pili muscles and to the adrenal medulla. The parasympathetic preganglionic motoneurons are found within the sacral spinal cord; they provide a parasympathetic innervation to the pelvic viscera and the hindgut.

Summary This study was conducted as a comparative analysis of the immunohistochemical localization of calbindin D-28k, parvalbumin and the calcitonin gene-related peptide (CGRP) in the cervical through the sacral spinal cord of mongrel dogs, to reveal any distinct patterns of distribution and possible involvement in spinal processing. In laminae I and II of the substantia gelatinosa, both calbindin D-28k and CGRP showed strong immunoreactivity, with calbindin D-28k being positive in both cells and fibres, while CGRP was positive in fibres only. Parvalbumin and CGRP immunoreactive cells were widely distributed in various nuclei and lower motor neurones in the ventromedial horn. In addition, the lower motor neurones expressed CGRP as well as parvalbumin, but not calbindin D-28k. These results are generally consistent with previous reports, and the co-localization of parvalbumin and CGRP may explain the functional improvement of lower motor neuron disease.

R. Chiocchetti1,∗, A. Grandis1, C. Bombardi1, M. Joechler2, L. Pisoni2 and A. Gentile2 1Department of Veterinary Morphophysiology and Animal Productions, Faculty of Veterinary Medicine, University of Bologna, Ozzano dell’Emilia (BO), Italy; 2Veterinary Clinical Department, Faculty of Veterinary Medicine, University of Bologna, Via Tolara di Sopra, 50, 40064, Ozzano dell’Emilia (BO), Italy ∗Correspondence: E-mail: chiocchetti@vet.unibo.it

Over the months following sacral spinal cord transection in adult rats, a pronounced spasticity syndrome emerges in the affected tail musculature, where long-lasting muscle spasms can be evoked by low-threshold afferent stimulation (termed long-lasting reflex). To develop an in vitro preparation to examine the neuronal mechanisms underlying spasticity, we removed the whole sacrocaudal spinal cord of these spastic chronic spinal rats (>1 mo after S2 sacral spinal transection) and maintained it in artificial cerebral spinal fluid in a recording chamber. The ventral roots were mounted on monopolar recording electrodes in grease, and the reflex responses to dorsal root stimulation were recorded and compared with the reflexes seen in the awake chronic spinal rat. When the dorsal roots were stimulated with a single pulse, a long-lasting reflex occurred in the ventral roots, with identical characteristics to the long-lasting reflex in the awake spastic rat tail. The reflex response was low threshold ( T), short latency, long duration (∼2 s), and enhanced by repeated stimulation. Brief high-frequency stimulation trains (0.5 s, 100 Hz, 1.5 × T) evoked even longer duration responses (5–10 s), with repeated bursts of activity that were similar to the repeated muscle spasms evoked in awake rats with stimulation trains or manual skin stimulation. Stimulation of a given dorsal root evoked long-lasting reflexes in both the ipsilateral and contralateral ventral roots. Long-lasting reflexes did not occur in the sacrocaudal spinal cord of acute spinal rats (S2 transection), which is similar to the areflexia seen in awake acute spinal rats. However, long-lasting reflexes could be made to occur in the acute spinal rat by altering K+ (7 mM) or Mg2+ (0 mM) concentrations, or by application of high doses of the neuromodulators norepinephrine (NE, >20 μM) or serotonin (5-HT, >20 μM). In chronic spinal rats, much lower doses of these neuromodulators (0.1 μM) enhanced the long-lasting reflexes, suggesting a denervation supersensitivity to 5-HT and NE following injury. Higher doses of NE or 5-HT produced a paradoxical inhibition of the long-lasting reflexes. The high dose inhibition by NE was mimicked by the α2-adrenergic receptor agonist clonidine but not the α1-adrenergic receptor agonist methoxamine. In summary, the sacral spinal in vitro preparation offers a new approach to the study of spinal cord injury and analysis of antispastic drugs.