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Objectives: Accurate neurological diagnoses are often difficult to make due to the complexity of the neuroanatomy involved. This study was performed to evaluate the usefulness of a computer system with easily retrievable anatomical information as a support for arriving at more accurate anatomic diagnoses. Patients and methods: Anatomical information from an initial physical examination was programmed into a computer with stored neuroanatomical charts of the brain, spinal cord and peripheral nerves. The information generated a graphic display of possible lesions with suggestions for further examination. These suggestions were then followed and further data entered. This data entry generated a new graphic display with reduced lesion possibilities. Iterations were then followed to narrow the possibilities for diagnosis further, until a final anatomical diagnosis was reached. This method was applied to three hypothetical examples and a number of clinical cases. Here we report three clinical cases in which this method was particularly useful in making a diagnosis. Results: Using computer iterations, the system was able to pinpoint one or more presumptive causative lesions in the CNS or PNS based on known neuronal pathways or nuclei. Conclusion: The results indicate that suitably used, computer memory, by virtue of its large capacity, accuracy and fast recall, can supplement human memory in reaching accurate anatomical diagnoses of neurological lesions.

Terminal Schwann cells (TSCs) that cover motor neuron terminals, are known to play an important role in maintaining neuromuscular junctions, as well as in the repair process after nerve injury. However, the molecular characteristics of TSCs remain unknown, because of the difficulties in analyzing them due to their paucity. By using our previously reported method of selectively and efficiently collecting TSCs, we have analyzed the difference in expression patterns of lysophospholipid (LPL) receptor genes (LPA1, LPA2, LPA3, S1P1, S1P2, S1P3, S1P4, and S1P5) between TSCs and myelinating Schwann cells (MSCs). LPL, which includes lysophosphatidic acid (LPA) and sphingosine 1-phosphate (S1P), is the bioactive lipid that induces a myriad of cellular responses through specific members of G-protein coupled receptors for LPA. It turned out that LPA3 was expressed only in TSCs, whereas S1P1 was expressed in TSCs and skeletal muscle, but not in MSCs. Other types of LPL receptor genes, including LPA1, S1P2, S1P3, S1P4, were expressed in both types of Schwann cells. None of the LPL receptor gene family showed MSCs-specific expression.

To elucidate blood-nerve barrier function and tight-junction protein expression in the dorsal root ganglion (DRG), we analyzed the vascular permeability in the rat DRG by i.v. administration of fluorescent Evans-blue albumin (EBA) and compared it with the localization of claudin-1, claudin-5, and occludin by immunoconfocal microscopy. In the cell body-rich area within the DRG, extravascular leakage of EBA was noted and claudin-5 but neither claudin-1 nor occludin was detected. Conversely, in the nerve fiber-rich area within the DRG, no extravascular leakage of EBA was observed and both claudin-5 and occludin but no claudin-1 were detected in the blood vessel. These results demonstrate regional differences in the blood-nerve barrier function and tight-junction protein expression within the DRG.

Terminal Schwann cells (TSCs) that cover motor neuron terminals are known to play important roles in maintaining neuromuscular junctions, as well as in the repair process after nerve injury. However, molecular characteristics of TSCs remain unknown, because of the difficulties in analyzing them due to their paucity. We have established a method of selectively and efficiently collecting TSCs so that cDNA analysis can be done properly. The expression of 1–2% of whole mRNAs was compared between myelinating Schwann cells (MSCs) and TSCs, and it turned out that approximately one-third of the bands could be categorized as cell-type-specific bands. TSCs thus constitute a distinct entity from the viewpoint of gene expression. As one of the cDNA clones belonging to TSC-specific bands was identified homocysteine-responsive ER-resident protein (Herp), and in situ hybridization confirmed that Herp mRNA is expressed in TSCs on motor nerve terminals but not in MSCs, both in developing and adult rats. In conclusion, we have been able to identify Herp as a novel molecular marker for TSCs.

The blood-nerve barrier in peripheral nerves is important for maintaining the environment for axons. Breakdown of the barrier by nerve injury causes various pathologies. We hypothesized that the breakdown and recovery of the blood-nerve barrier after injury are associated with the changes in the expression of intercellular junctional proteins. To test this hypothesis, we induced crush injuries in the rat sciatic nerve by ligation and analyzed spatiotemporal changes of claudin-1, claudin-5, occludin, VE-cadherin, and connexin43 by immunoconfocal microscopy and morphometry and compared them with changes in the permeability of the blood-nerve barrier by intravenous and local administration of Evans blue-albumin (EBA). On day 1 after removal of the ligature EBA leaked into the connective tissue in the endoneurium and then the leakage gradually decreased and disappeared on day 7. On day 1 claudin-1, claudin-5, occludin, VE-cadherin, and connexin43 had totally disappeared from the perineurium and endoneurium. Thereafter, claudin-1, claudin-5, occludin, and VE-cadherin recovered from day 2, whereas connexin43 was redetected on day 5. These results indicate that the breakdown and following recovery of the blood-nerve barrier are closely associated with changes in the expression of claudins, occludin, VE-cadherin, and connexin43 and that the recovery time course is similar but nonidentical.

Operationsziel Alle Operationsschritte lassen sich uber einen einzigen dorsomedialen Zugang vornehmen. Durch Dekompression des Nervus ulnaris, Resektion von Osteophyten und ggf. des Radiuskopfchens sowie Entfernung freier Gelenkkorper soll ein Ruckgang der Schmerzen und Parasthesien erzielt werden. Indikationen Sulcus-ulnaris-Syndrom mit chronischem Schmerz, beeintrachtigter Funktion sowie einer Neuropathie Grad II oder III des Nervus ulnaris bei fortgeschrittener Arthrose des Ellbogengelenks. Kontraindikationen Lange bestehendes Sulcus-ulnaris-Syndrom mit fortgeschrittener Muskelatrophie und ausgepragten Sensibilitatsstorungen. Schwere Osteoarthrose des Ellbogengelenks. Operationstechnik Uber einen dorsomedialen Zugang mit Spaltung des Musculus triceps brachii mediale Epikondylektomie; ggf. Radiuskopfchenresektion; uber eine Fensterung der Fossa olecrani Resektion von Osteophyten; uber eine mediale Kapsulotomie Resektion von Osteophyten und Entfernung freier Gelenkkorper. Weiterbehandlung Immobilisation des Ellbogengelenks mit Oberarmgipsverband fur 2 Wochen. Nach Wundverheilung Unterwassertherapie, passive und aktive Bewegungsubungen. Ergebnisse Zwischen 1978 und 1992 wurden 28 Ellbogen bei 25 Patienten (23 Manner, zwei Frauen, Durchschnittsalter [15–70] Jahre) operiert. Alle Patienten konnten nach durchschnittlich 68 (26–170) Monaten nachuntersucht werden. Nach den Kriterien des British Nerve Injuries Committee wurden die klinischen Resultate bei sechs Patienten als sehr gut, bei 14 als gut, bei vier als mas und bei einem als schlecht beurteilt. Der Ellbogenschmerz bei manueller Tatigkeit besserte sich bei 10 Patienten deutlich, bei vier Patienten leicht und blieb bei sechs Patienten unverandert. Parasthesien verbesserten sich bei 20 Patienten und blieben bei funf Patienten unverandert. Die Kraft beim Greifen stieg von einem praoperativen Durchschnittswert von 26,4 kg auf postoperativ 29 kg an.

This study investigated sensory nerve distribution in 27 human coracoacromial ligaments by immunohistochemical methods using antiprotein gene product 9.5 antibody and anticalcitonin gene related peptide antibody. Mean nerve densities were compared among three areas (acromion side, center, and coracoid side) in two groups (patients with rotator cuff tears and patients with shoulder dislocations). In all three areas of both groups, many nerve fibers immunoreactive to antiprotein gene product 9.5 antibody were observed in the periligamentous bursal tissue. However, in the ligament parenchyma, nerve fibers immunoreactive to antiprotein gene product 9.5 antibody were recognized only around blood vessels. Nerve fibers immunoreactive to anticalcitonin gene related peptide antibody were recognized in the periligamentous bursal tissue. However, in the ligament parenchyma, there were no nerve fibers immunoreactive to anticalcitonin gene related peptide antibody. Nerve density of the rotator cuff tear group, as revealed by both immunostainings, showed a significant increase compared with that of the shoulder dislocation group in all three areas. The results of this study show that it is possible the increase in sensory nociceptive nerve fibers in the coracoacromial ligaments may be one of the causes for pain in patients with rotator cuff tears.

Synaptosomal-associated protein 25 has been regarded as one of the target-associated soluble N-ethylmaleimide-sensitive fusion attachment protein receptors essential for exocytosis of vesicles in synapses. We have previously reported that cleavage of syntaxin, which is another target-associated soluble N-ethylmaleimide-sensitive fusion attachment protein receptor, with botulinum neurotoxin C1 resulted in inhibition of neurite extension and morphological changes including growth cone collapse and large vacuole formation. As an attempt to explore the mechanism of growth cone extension, we examined the ultrastructural localization of synaptosomal-associated protein 25 in growth cones with or without treatment of botulinum neurotoxin A, which cleaves synaptosomal-associated protein 25. In dorsal root ganglion neurons, light microscopy demonstrated synaptosomal-associated protein 25 immunoreactivity throughout the neurons, including the cell bodies, neurites and growth cones. Using electron microscopy, gold signals immunoreactive for synaptosomal-associated protein 25 were identified diffusely in the cytoplasm of the growth cones. In contrast, in PC-12 cells, a large number of gold signals were localized on the plasma membranes. High levels of signal were also found in the cytoplasm in the central region of the growth cones. We also confirmed that botulinum neurotoxin A treatment reduced neurite extension by about 50%. However, both in dorsal root ganglion neurons and in PC-12 cells we found no differences in the ultrastructure nor in the localization of synaptosomal-associated protein 25 between growth cones with and without toxin treatment. These results indicate that cleavage of synaptosomal-associated protein 25 inhibits growth cone extension in a manner different than that of syntaxin cleavage. The results of this study suggest the possibility that synaptosomal-associated protein 25 is involved in growth cone extension through a process independent of vesicle fusion.

The morphological study of cubital tunnel, carpal tunnel and the ulnar (Guyon) canal of adult cadavers was done using stereoscopy after injection of the resin into the brachial artery. MRI (Magnetic Resonance Imaging) of the carpal tunnel was also performed for normal volunteers. In the area of sulcus nervi ulnaris at the elbow, the amount of fibrofatty tissue was extremely small in the nerve trunk, and the nerve was superficially located and found to run close to the hard bony tissue. At the distal margin of the bony sulcus of the ulnar nerve, the nerve ran on the base of hard collateral ligament, where it was covered with a hard ligamentous aponeurosis. The nutrient vessel to the epineurium of the nerve did not exist in the tunnel under the cover of aponeurosis and the nerve was fed by vessels at the entrance of the tunnel and by the recurrent vessels ascending from the musculature at the distal end of the tunnel. The thickness of the flexor retinaculum from the inlet to the midst of carpal tunnel increases and the thickness became maximum at the outlet. The images of MRI of the carpal tunnel were similar to the corresponding levels, and demonstrated the accuracy of imaging with the anatomical relationships. The ulnar canal itself had few bone elements, and there were neither tight connective tissue nor tendons on the palmar side except for the inlet portion.

The present study, using confocal laser scanning microscopy and immunoelectron microscopy, examined the intracellular localization of tyrosine-phosphorylated proteins in cultured mouse dorsal root ganglion neurons with special reference to their growth cones. The growth cone is the specialized structure formed at the growing tip of the axon; characteristically highly motile with filopodia on the surface, it is responsible for the extension and guidance of the neurites to the appropriate targets during nerve regeneration. It has been suggested that protein-tyrosine phosphorylation plays an important role in the intracellular signal transduction that regulates the extension and motility of growth cones. By fluorescence immunocyto-chemistry, phosphotyrosine immunoreactivity was found in the growth cones and neurites. Some of the filopodia exhibited strong immunoreactivity at their tips. By immunoelectron microscopy, a large number of immunogold particles (gold particles conjugated to the secondary antibody) were seen to be distributed in the cytoplasm and some were observed on the plasma membrane in the growth cones, whereas in the neurites the density of immunogold particles was the same in the axoplasm as on the plasma membranes. These findings suggest that in the growth cones phosphotyrosines might mainly be involved in intracellular signaling for maintaining their high motility whereas in the neurites they might mostly be associated with the receptor proteins at the plasma membrane for adhesion as well as for growth of neurites. Thus, tyrosine phosphorylation might contribute to different functions for growth cones and neurites.

The distribution of protein kinase C (alpha, beta, gamma subtypes) was studied using immunocytochemical techniques in normal nerve fibers and in regenerating sprouts (growth cones) from the nodes of Ranvier following crush injuries to the rat peripheral nervous system. In normal nerves, for each protein kinase C subtype, immunoreactivity was present in both myelinated and unmyelinated axons. In myelinated axons, immunoreactivity for all three subtypes was patchy in the axoplasm and diffuse in the subaxolemmal peripheral zones. No immunoreactivity was found in the microtubule and neurofilament (cytoskeletal) domain. In contrast, in unmyelinated axons, immunoreactivity was distributed diffusely in the axoplasm. Schwann cells of myelinated fibers exhibited protein kinase C immunoreactivity, but those of unmyelinated fibers did not. In regenerating nerves, early sprouts and growth cones extending through the crushed site along Schwann cell basal laminae exhibited intense immunoreactivity for all three subtypes. Immunoreactivity was distributed diffusely throughout the axoplasm of the regenerating sprouts (growth cones), in which microtubules and neurofilaments were very rare. Thus, the subcellular localization of the protein kinase C immunoreactivity in growth cones of early regenerating nerves differed from that of normal parent axons. These findings suggest that protein kinase C (alpha, beta and gamma subtypes), whose subcellular distribution becomes more extensive in regenerating axons, may have important functional roles in axonal sprouting and in the regulation of growth cone activity in the peripheral nervous system.

Many techniques and instrument systems have been developed for performing arthroscopic Bankart repair using a suture anchor. The suture anchor procedure relies on a secure knot, which does not become entangled in the anterior portal. A newly devised anterior portal technique can solve this problem. We have used this technique for arthroscopic Bankart repair using suture anchor. This technique may be useful for any type of suture materials such as SLAP lesion.

Following crush injury of rat sciatic nerve, strong synaptophysin immunoreactivity was demonstrated in the regenerating sprouts that emerged from the proximal nodes of Ranvier and in their growth cones that extended through the space between Schwann cell basal lamina and myelin sheath of the parent axon. These findings suggest that synaptophysin is involved in the growth regulation of regenerating sprouts.

Sprouting from crush-injured rat sciatic nerves was studied by electron microscopy to clarify how regenerating sprouts are generated at the node of Ranvier and extended distally in the injured nerves. Three hours after injury, sprouting had already begun in a few nodes: part of the dense submembranous undercoat had disappeared from the nodal axolemma, and the axolemma was slightly evaginated where the undercoat was avoided. The sprout contained clear vesicles of about 50 nm in diameter in an amorphous axoplasm. In addition, vacuoles measuring 100-200 nm in diameter and multivesicular bodies were commonly found within or near these early sprouts. Six to 12 h after injury, nodes of Ranvier with sprouts increased in number in the region 1-1.5 mm proximal to the lesion. Sprouts grew toward the overlying Schwann cell basal lamina, and extended through the space between the basal lamina and Schwann cell plasmalemma (or myelin sheath). In the stem region continuous with the parent axon, regenerating sprouts displayed prominent neurofilaments, which were randomly arranged at 1 day post-injury, but oriented longitudinally by 5 days post-injury.

手指屈筋腱損傷の一次修復後のリハビリテーションとして現在Kleinert法が広く行われている.しかし指尖の牽引方向によってはDIP関節およびPIP関節の可動域制限が生じるなど解決されるべき問題が残存する.こういった問題に対処する目的で遠位手掌皮線上にpulleyを設置したmodified Kleinert法が考案されている.今回われわれはmodified Kleinert法の改良点を評価するために健常成人男女各5名(計10名)を対象に指尖に加わる張力の大きさ,方向とDIP関節の動きとの関係についてKleinert法とmodified Kleinert法を比較検討した.pulley設置群(modified Kleinert法)は非設置群(Kleinert法)に比べ大きな関節可動域が得られた.指尖部に加わる回転モーメントは非設置群の方が大きく,DIP関節の伸展とともにその値は増加した.一方pulley設置群では約35°のDIP関節屈曲位にて指尖部に最大回転モーメントが加わり,以後伸展とともにその値は減少した.以上よりmodified Kleinert法が一次修復後の後療法としてより有用であると思われた.

Neuregulins belong to a family of multipotent growth-promoting proteins, and have been shown to have a crucial role in accumulating acetylcholine receptor at neuromuscular junctions. A functional role of neuregulins in muscle regeneration has not yet been identified. Using reverse transcription (RT)-PCR, Western blot and immunofluorescence analysis following bupivacaine injection into rat muscle, we investigated the expression pattern of neuregulin-1 (NRG-1) in normal and regenerating tibialis anterior (TA) muscle. In addition, we examined changes in NRG-1 expression in the spinal cord following muscle damage. Western blotting showed that muscle NRG-1 protein decreased soon after the damage, and increased gradually after the 4th day following the damage. The amount of NRG-1 mRNA in the muscle increased from the 2nd to 6th post-surgical day. The amount of NRG-1 protein, but not mRNA, increased gradually in the spinal cord after muscle damage. Immunofluorescence revealed NRG-1 protein in some quiescent satellite cells identified by c-Met. After 6 and 10 days, clear co-localization between NRG-1 and myogenin was noted in differentiating satellite cells. Thus, NRG-1 may play an important role in the differentiation of satellite cells in muscle regeneration, while increased NRG-1 expression in motoneurons may enhance the remodeling of partially damaged axons.

We report on the surgical results of spinal accessory nerve injuries between 1992–2003. We operated on 10 patients (9 female, and 1 male) who had injuries of the spinal accessory nerve. All injuries were iatrogenic. The mean age of patients was 39.2 years (range, 20–57 years). The average interval between date of injury and surgery was 7 months (range, 4–12 months). All patients had stiffness and pain in the shoulder girdle. The average active abduction of the shoulder joint was 79.5° (range, 60–100°) before surgery. End-to-end repairs were performed in 7 cases, and graft repairs were indicated in 3 cases. The mean follow-up period was 18.4 months (range, 8–36 months). The average active abduction of the shoulder joint was 171° (range, 140–180°) at time of final follow-up. © 2006 Wiley-Liss, Inc. Microsurgery, 2006.

Limited perineurial injury, known as a perineurial window, can lead to neuropathic pain. This article hypothesizes that the recovery of the perineurium is associated with the intercellular junctional proteins. It analyzes the expressions of occludin, ZO-1, and connexin 43 by immunoconfocal microscopy. Seven days after injury, immunoreactivities for occludin and ZO-1 were observed, although there was no connexin 43 detected. Then, 21 days after injury, immunoreactivity for connexin 43 were observed. These results indicate that recovery of the perineurium is associated with the intercellular junctional proteins and that the recovery of gap junctions is delayed compared with that of tight junctions.

Among the pathological sequelae of facial paralysis is a paralytic eye. Apart from the psychological and aesthetic deficits, facial paralysis if left untreated can lead to dryness, ulceration and eventual blindness. Although numerous restorative microsurgical approaches have been introduced to address the sequelae of this problem, complete restoration of function to denervated facial muscles remains elusive.Utilizing the rat model of facial paralysis the present research has as an objective to examine a dual treatment approach. Specifically, this study combined the current microsurgical treatment of the cross-facial nerve graft with local administration of insulin-like growth factor I (IGF-I).The efficacy of this combined approach (cross-facial nerve graft + IGF-I) was assessed in the following ways: (a) behavior measurement of the blink response and (b) histomorphometry light and electron microscopy of the entire nerve graft. These data will help provide insight into the restoration of facial muscle function after trauma and assist in the future development of more potent treatment strategies.7he local adnünistration of IGF-I (50 micro g/ml) to the cross-facial nerve graft was found to restore the blink response faster and to strengthen the degree of eye closure. Light microscopy examination revealed that IGF-I significantly enhanced axonal regeneration within a nerve graft (a 22% increase in the mean number of axons), and increased the mean nerve fiber diameter and myelin thickness. Electron microscopy assessment of the nerve grafts demonstrated that the IGF-I treated grafts possessed a greater density of microtubules, which were evenly distributed within the axoplasm.

Obstetric brachial plexus palsy invariably involves the upper roots. If left untreated, characteristic deformities of the shoulder are common sequelae. The most objective way to investigate these shoulder deformities is computed tomographic (CT) scanning of bilateral upper limbs. In this study, specific measurements on CT scans of bilateral upper extremities were performed in a population of patients with obstetric brachial plexus palsy before and after reconstruction (nerve repairs and secondary procedures). The measurements showed that the restoration of external rotation and the scapula stabilization procedure correct the inclination of the humeral head, improve the joint congruency significantly, and decrease the winging of the scapula, thus improving the kinetics of the shoulder. Periodic CT measurement is an objective method of measuring the changes at the shoulder joint that occur over time during the natural evolution of the obstetric brachial plexus palsy lesion and of documenting the benefits of microsurgical intervention.

For the regeneration of injured peripheral nerves, we have devised a PGA-tube that is composed of a tube of polyglycolic acid containing collagen sponge. This PGA-tube was applied clinically to reconstruct a peripheral nerve that had been resected during extended surgical resection of for intrapelvic recurrent rectal cancer. Four months after the surgical resection, the function of the left hip joint has improved remarkably, whereas the function had been lost just after the operation. It is suggested that the PGA-tube will be useful for regeneration of peripheral nerves that are resected during operation for intrapelvic malignancy.

Many techniques and instrument systems have been developed for performing arthroscopic Bankart repair using a suture anchor. The suture anchor procedure relies on a secure knot, which does not become entangled in the anterior portal. A newly devised anterior portal technique can solve this problem. We have used this technique for arthroscopic Bankart repair using suture anchor. This technique may be useful for any type of suture materials such as SLAP lesion.

Growth cones of regenerating nerves, following crush injury to the rat peripheral nerve system, were studied by electron microscopy and synaptophysin. Localization in the growth cones was revealed by immunohistochemistry at the ultrastructural level. Many regenerating growth cones grew along the Schwann-cell basal laminae tubes at the crushed site. These cones revealed an abundance of organelles, such as heterogenous vesicles and many mitochondria, and a scarcity of cytoskeletons, including microtubules and neurofilaments in the cytoplasm. The periphery of the growth cones (corresponding to the lamellipodia or filopodia of cultured neurons) contained rich electron-dense filamentous materials. Cellular protrusions, such as filopodia, were rarely seen. These growth cones exhibited intense immunoreactivity for synaptophysin by light microscopy. Immunoelectron microscopy demonstrated that immunoreactivity was distributed diffusely in the cytoplasm.

Recent studies suggest that the soluble N-ethylmaleimide-sensitive factor attached protein (SNAP) receptor (SNARE)-mediated membrane fusion system is involved in vesicle fusion in the plasma membrane that allows expansion for neurite elongation. There have been several reports analyzing the effects of neurite outgrowth by inhibition of SNAREs. In this study, we took the opposite approach by overexpressing green fluorescent protein (GFP)-fusion SNAREs, including VAMP-2, SNAP-25A, and syntaxin1A, in PC12 cells to investigate the role of SNAREs in the neurite outgrowth of PC12 cells. Neurite outgrowth analysis demonstrated that: (1) GFP-VAMP-2 increased the length of individual neurites, without changing the number of neurites per cell; (2) GFP-SNAP-25A increased the number of neurites per cell, with no change in the length of the individual neurites. In both cases, the total length of neurites per cell was increased; (3) GFP-syntaxin1A resulted in no significant change, either in neurite length, or in the number of neurites per cell. These findings suggest that when overexpressed in PC12 cells, VAMP-2 can promote neurite elongation, while SNAP-25A can stimulate neurite sprouting. On the other hand, overexpression of syntaxin1A neither promotes nor inhibits neurite outgrowth. Thus VAMP-2 and SNAP-25A play different roles in neurite elongation and sprouting.

The ultrastructure of the early regenerative response in an end-to-side neurorrhaphy rat model was studied using transmission electron microscopy. The ipsilateral saphenous nerve was grafted to the sciatic nerve under the following conditions: Group 1, the epineurium and perineurium of the sciatic nerve remained intact; Group 2, an epineurial and perineurial window was created at the site of the lateral neurorrhaphy; Group 3, the same as in Group 2 and, in addition, the sciatic nerve sustained a partial neurectomy. Rats were perfused through the heart with fixative containing 2 percent paraformaldehyde and 2.5 percent glutaraldehyde in 0.1 M cacodylate buffer (pH 7.4) at 4, 8, 12, 24 and 48 hr after surgery. In Group 1, no regenerating axons were observed and the myelin sheath in the donor nerve did not demonstrate any degenerative changes through 48 hr. In Group 2, an increased diameter of the unmyelinated axons and growth cones was observed in the donor nerve proximal to the coaptation site after 12 hr. Degenerative changes in the myelin sheath were observed after 12 hr within the several layers under the coaptation site. In Group 3, many growth cone-like structures were observed in the area proximal to the coaptation site after 12 hr. After 24 hr, proximal regenerating axons elongated to the coaptation site and, at 48 hr, many regenerating nerves grew inside the Schwann cell basement membrane of the graft nerve. These results indicate that the perineurial window and nerve graft are the critical conditions for inciting nerve regeneration in the donor nerve.

The nerve distribution to the knee joints was analyzed in 5 cadavers and 10 joint capsules specimens were resected during total knee arthroplasty. We found nerve fibers immunoreactive for anti-substance P antibody in the articular capsule. By confocal laser scanning microscopy, we evaluated the three-dimensional structures of the Ruffini's corpuscles and the free nerve endings, both of which were immunoreactive for anti-protein gene product 9.5.

Rat sciatic nerve crush injury is one of the models commonly employed for studying the mechanisms of nerve regeneration. In this study, we analyzed the temporal change of gene expression after injury in this model, to elucidate the molecular mechanisms involved in nerve regeneration. First, a cDNA analysis method, Restriction Landmark cDNA Scanning (RLCS), was applied to cells in the ventral horn of the spinal cord during a 7-day period after the crush injury. A total of 1991 cDNA species were detected as spots on gels, and 37 of these were shown to change after the injury. Temporally changed patterns were classified into three categories: the continuously up-regulated type (10 species), the transiently up-regulated type (22 species), and the down-regulated type (5 species). These complex patterns of gene expression demonstrated after the injury suggest that precise regulation in molecular pathways is required for accomplishing nerve regeneration. Secondly, the rat homologue of uridine kinase gene was identified as one of the up-regulated genes. Northern blot analysis on rat ventral horn tissue and brain revealed that the UK gene had three transcripts with different sizes (4.3, 1. 4, and 1.35 kb, respectively). All of the transcripts, especially the 4.3 kb one, were up-regulated mainly in a bimodal fashion during the 28-day period after the injury. The RLCS method that we employed in the present study shows promise as a means to fully analyze molecular changes in nerve regeneration in detail.

We immunohistochemically and morphometrically examined the expression of gap junction protein connexin (Cx) in normal and crush-injured rat sciatic nerves using confocal laser scanning microscopy. Cx26 was localized in the perineurium and Cx43 was present in the perineurium and the epineurium, whereas Cx32 was confined to the paranodal regions of the nodes of Ranvier. Double labeling for connexins and laminin revealed that Cx43 was localized in multiple layers of the perineurium, whereas Cx26 was confined to the innermost layer. Double labeling for connexins and a tight junction protein, occludin, showed that occludin frequently coexisted with Cx43 but existed separately from Cx26 in the perineurium. After crush injury, the pattern of normal Cx32 expression was initially lost but recovered, whereas Cx43 rapidly appeared in the endoneurium and its expression was subsequently attenuated. Although crush injury produced no apparent alteration in Cx43 and occludin in the perineurium, a rapid increase and a subsequent decrease in the frequency of Cx26-positive spots during nerve regeneration were shown by morphometric analysis. These results indicate that Cx26, Cx32, and Cx43 are expressed differently in various types of cells in peripheral nerves and that their expressions are differentially regulated after injury. The expression of connexins and occludin in the perineurium suggests that perineurial cells are not uniform in type and that the regulation of gap junctions and tight junctions is closely related in the perineurium.

Hippocrates provided the first written description of the peripheral nervous system (PNS), as early as the 4th century B.C., and later Herophilus identified nerves as such, distinguished them from tendons; he also traced nerves to the spinal cord. The traditional Hippocratic teaching of the time, however, doubted that nerve healing occurred. Through the subsequent centuries, several papers were written about the PNS but, without sufficient understanding of anatomy, physiology, and the regenerative capacity of the PNS, it is not difficult to comprehend the frustration that might have been encountered by surgeons in dealing with nerve injuries and their subsequent repair. This was probably the reason why nerve repair was rarely actually undertaken prior to the 19th century. A plethora of studies on the PNS and its regeneration has been reported over the last 150 years and has provided us with current knowledge. It is important, before describing the most recent developments in the area of peripheral nerve regeneration, to briefly outline the major advances over the last century. Currently, the therapeutic approaches taken toward the patient with peripheral nerve injury change continuously. Sophisticated advances in technology, cellular and molecular neurobiology, and electron microscopy will doubtless optimize reconstructive strategies in treating nerve injury. A greater awareness and understanding of the nerve ultrastructure, as well as the underlying mechanisms of the regenerative process and those factors detrimental to nerve regeneration, will assist in the successful repair of nerve injury. This paper reviews the cellular, biochemical, and ultrastructural elements of nerve injury and repair, and the rationale for current reconstructive strategies and techniques.

Normal intact and regenerating axon terminals up to 30 days after nerve crushing were studied in the rat flexor carpi ulnaris muscle by confocal laser scanning microscopy (CLSM) and electron microscopy using immunohistochemistry for protein gene product 9.5 (PGP 9.5). The motor axons were intensely and homogeneously stained along their entire length. "Three dimensional" organizations of elaborate axon terminals were clearly demonstrated by reconstructing serial optical images obtained by CLSM in normal neuromuscular junctions. In the injured nerve, the earliest regenerating axons could be identified at endplate regions six days after nerve crushing as intensely immunoreactive thin processes which bifurcated in T-shape and formed delicate lace-like terminals. Such lace-like terminals were composed of fine thread-like portions 0.2-0.8 microm in diameter and expanded portions of 2-3 microm in diameter. Electron microscopy revealed that all the axon terminals in the cytoplasm were stained almost homogeneously by PGP 9.5 immunohistochemistry up to their extreme tips. Axon terminals were in direct contact with the basal lamina of the postsynaptic folds, and showed occasional branching. The thin thread-like portions contained no mitochondria but only a few vesicles, where as the expanded portions, abundant mitochondria. And preterminal axons and some expanded portions were abutted by Schwann cells, while thin thread-like portions were exposed with no association with Schwann cells. Twenty to 30 days after crushing injury, regenerating motor axon terminals resumed their mature form in terms of branching elaborations and ultrastructural features. Thus, CLSM of PGP 9.5 immunocytochemistry combined with electron microscopy was able to demonstrate the "three-dimensional" organization of elaborate axon terminals at high resolution in the normal and regenerating neuromuscular junctions. Using this technique, extremely fine processes of axonal terminals were identifiable at the earliest stage of reinnervation.