Restorative Neurology and Neuroscience - Volume 5, issue 3

Authors: Borgens, Richard B. | , M.E. Mourey | Metcalf, | Blight, Andrew R.

Article Type: Research Article

Abstract: The cutaneus trunci muscle (CTM) reflex of guinea pigs depends on an ascending afferent pathway within the ventrolateral funiculus of the thoracic spinal cord. The expression of this reflex is a phasic contraction of back skin in response to tactile stimulation, which is permanently eliminated by transection of the ventrolateral funiculus. It was shown previously that when a polarized (rostrally negative), weak (300–400 μV/mm) DC electric field is placed across a lateral hemisection of the spinal cord in adult guinea pigs at the time of injury, approximately 13% recover the reflex, while sham-treated animals remain unchanged. In this study, a …similar approach was used, except that three months were allowed to pass between the time of hemisection and experimental treatment. No recovery of the CTM reflex was observed in 13 animals with rostrally negative fields, 8 of which were followed for at least 9 months, 5 for 3 months; or in 11 animals with caudally negative applied fields, 8 of which were followed for 9 months and 3 for 3 months. Show more

Keywords: Spinal cord, Regeneration, Electrical field, Guinea pig

DOI: 10.3233/RNN-1993-5301

Citation: Restorative Neurology and Neuroscience, vol. 5, no. 3, pp. 173-179, 1993

Authors: Vergara, Jorge | Medina, Luis | Maulén, José | Inestrosa, Nibaldo C. | Alvarez, Jaime

Article Type: Research Article

Abstract: In rat sciatic nerves, IGF-I or bFGF was applied distal to a crush to evaluate their effects upon the restoration of the neuromuscular function. In comparison with the recovery following a simple crush, treatment with growth factors resulted in (i) enhanced elongation of regenerating axons ( + 24%) up to day 3 post lesion (PL); (ii) more sprouts at early times; (iii) reduced participation of macrophages in the removal of the degenerating myelin in the first week PL; (iv) restoration of the neuromuscular transmission 2 days earlier; (v) a prolonged relaxation time and a reduced specific tetanic tension at week …3 PL but not at week 7 PL. Other indicators of recovery such as conduction velocity of nerve impulse, muscle weight, specific twitch tension, and time to peak were not affected by bFGF or IGF-I. Results suggest that IGF-I and bFGF affect locally Schwann cells and axons, and also the neuron as a whole, including its trophic function. We conclude that IGF-I and bFGF applied to the nerve, albeit moderately, improve the recovery of the neuromuscular function. Show more

Keywords: Sciatic nerve, Axon, Macrophage, Denervation, Trophism, Wallerian degeneration, Schwann cell

DOI: 10.3233/RNN-1993-5302

Citation: Restorative Neurology and Neuroscience, vol. 5, no. 3, pp. 181-189, 1993

Authors: Kreischer, Arno | Kleinebeckel, Dieter | Klußmann, Friedrich Wilhelm

Article Type: Research Article

Abstract: The common peroneal nerve was transected bilaterally in 25 adult mice. Nerve stumps were immediately readapted without nerve suture. Before transection and after nerve regeneration the muscle coordination of tibialis anterior (TA) and medial gastrocnemius (MG) muscle was examined by electromyographic recordings from both muscles (EMG) during free running. Using a personal computer, the degree of muscle coordination between TA and MG was determined by calculating a coordination index. In normal mice an antagonistic innervation pattern was observed. After nerve transection and regeneration the degree of muscle coordination of TA and MG substantially decreased with great interindividual but also great …intraindividual variation. In 16 mice there was no correlation between the coordination index of the left and right hindlimbs. In nine out of 25 mice reinnervation was absent on one side. These results suggest that nerve regeneration by axonal sprouting to appropriate or foreign muscles occurs at random and that there are no intraindividual factors which might promote the finding of the proper target muscle. Show more

Keywords: Muscle coordination, Nerve transection, Nerve regeneration, Peroneal nerve, Tibialis anterior muscle, Electromyography, Computer-analysis

DOI: 10.3233/RNN-1993-5303

Citation: Restorative Neurology and Neuroscience, vol. 5, no. 3, pp. 191-196, 1993

Authors: Zhao, Qing | Dahlin, Lars B | Kanje, Martin | Lundborg, Göran

Article Type: Research Article

Abstract: Matrix formation within silicone tubes of different geometries implanted between the stumps of the transected rat sciatic nerve was studied. A matrix, composed of longitudinally oriented fibrin strands containing fibronectin, was formed within one day. The matrix then increased in size. The matrix contained macrophages and other inflammatory cells. Matrix size could be increased if the diameter of the tube was increased or if holes were made in the implanted tube. In contrast, matrix diameter decreased if the tube length was increased or if circulation was compromised in the inserts. The results suggest that the size, orientation and cellular components …of the matrix have profound effects on the regenerative response of the transected nerve. Show more

Keywords: Nerve regeneration, Peripheral nerve, Silicone, Implant, Matrix, Fibrin, Fibrinogen, Fibronectin, Immunohistochemistry, Nerve repair

DOI: 10.3233/RNN-1993-5304

Citation: Restorative Neurology and Neuroscience, vol. 5, no. 3, pp. 197-204, 1993

Authors: Koide, Kazuo | Hashitani, Takeshi | Aihara, Noritaka | Mabe, Hideo | Nishino, Hitoo

Article Type: Research Article

Abstract: Behavioral recovery and cell survival/growth after grafting of fetal striatal cell suspensions in the ischemic striatum of rats were investigated. Ischemia was induced by one hour intraluminal occlusion of the right middle cerebral artery under halothane anesthesia. During the ischemia rats usually manifested signs of hemiparesis and sometimes rotations. Behavioral function was measured by a passive avoidance task and radial arm maze test at 1–2 weeks and 6–7 weeks after ischemia. The size of the ischemic lesions depended on each animal, but the ischemic animals showed deficits in both passive avoidance task and radial maze test. Two weeks after ischemia, …fetal striatal cells, marked with DiI, were transplanted into the ischemic striatum. The transplantation improved the ischemia-induced deficit in the passive avoidance task but not in radial maze test. Although there were variations in the size of the grafts, many DiI-positive cells with dendritic outgrowth were detected under fluorescent microscopy. Immunohistochemical study revealed that many choline acetyltransferase (ChAT) positive cells and GABA-positive cells survived in the grafts. However, striosome-matrix compartments were not evident inside the grafts. Thus, partial recoveries in both cytoarchitectural and behavioral aspects were obtained by striatal cell grafts, suggesting that neural transplantation could be a useful approach in reconstructing ischemic brain function. Show more

Keywords: Middle cerebral artery, Ischemia, Striatum, Passive avoidance task, Transplantation, Immunocytochemistry, Rat

DOI: 10.3233/RNN-1993-5305

Citation: Restorative Neurology and Neuroscience, vol. 5, no. 3, pp. 205-214, 1993

Authors: Miettinen, R. | Lahtinen, H. | Riekkinen, P.J. | Freund, T.F. | Hsu, M. | Horváth, Z. | Buzsáki, G.

Article Type: Research Article

Abstract: Degeneration within the hippocampus was examined at the light microscopic level using the Gallyas silver stain two, four or nine months after bilateral transection of the fimbria-fornix and commissural connections. At two or four months after the lesion the strata oriens and radiatum of the subicular end of the CA1 subfields were strongly argyrophilic as was the inner third of the molecular layer of the dentate gyrus. At nine months post-lesion argyrophilia diminished but clearly persisted in the same layers. Electron microscopic examination revealed a large number of electron-dense axon terminals in the argyrophilic areas, most of them making asymmetric …synaptic contacts with dendritic spines. These findings suggest that at least a portion of the Schaffer collaterals of the CA3 pyramidal cells and associational collaterals of hilar neurons were in a process of acute degeneration at all time points after the initial surgical trauma. This persistent synaptic reorganization of intrahippocampal circuits may be related to abnormal electrical activity observed several months after fimbria-fornix transection. Show more

Keywords: Fimbria-fornix transection, Hippocampus, Epilepsy, Degeneration, Regeneration, Axotomy

DOI: 10.3233/RNN-1993-5306

Citation: Restorative Neurology and Neuroscience, vol. 5, no. 3, pp. 215-223, 1993

Authors: Ansselin, Annick D. | Davey, David F.

Article Type: Research Article

Abstract: The effect of proximo-distal orientation of peripheral nerve grafts upon axonal regeneration has been investigated using the sciatic nerve of the rat as a model. To test the hypothesis that the presence of nerve branches within a graft will cause misdirection of axons in normally oriented grafts but not in reversed grafts, all grafts studied contained branches. Qualitative electron microscopic examination of graft ultrastructure revealed no differences in nerve structure related to graft orientation. In most normally oriented grafts, branches persisted up to 12 months after surgery. These branches contained axons which terminated at the end of the branch. In …all reverse oriented grafts, and in a small number of normally oriented ones, the branches could not be seen after two or more months of regeneration. Axons sprouting outside of the epineurium of the graft caused the branch to be incorporated into the nerve structure. Axon counts in the distal stump of grafted nerves after twelve months recovery revealed that normally oriented grafts with persistent branches led to poorer peripheral regeneration, especially of unmyelinated fibers. The results indicate that regeneration of axons to their peripheral targets may be facilitated by reversing the graft orientation. Show more

Keywords: Peripheral nerve regeneration, Nerve graft, Axonal regeneration, Nerve branch, Axon sprouting, Reinnervation, Microsurgery

DOI: 10.3233/RNN-1993-5307

Citation: Restorative Neurology and Neuroscience, vol. 5, no. 3, pp. 225-240, 1993

Article Type: Research Article

DOI: 10.3233/RNN-1993-5308

Citation: Restorative Neurology and Neuroscience, vol. 5, no. 3, pp. 241-248, 1993