Restorative Neurology and Neuroscience - Volume 5, issue 5-6

Authors: Borgens, Richard B. | Toombs, James P. | Blight, Andrew R. | McGinnis, Michael E. | Bauer, Michael S. | Widmer, William R. | Cook Jr., James R.

Article Type: Research Article

Abstract: A clinical trial of applied, slowly oscillating, weak electric fields was performed in dogs with naturally occurring spinal cord injuries due to intervertebral disc herniation. Criteria for admission to the study were: complete paraplegia, defined by neurological examination and electrophysiological testing; intact segmental reflexes; radiologic and myelographic evidence of spinal cord compression due to disc herniation and a focal lesion, without appreciable rostrocaudal spread of necrosis; weight less than 16 kg; onset of paralysis less than 1 month before surgery. The injured cord was exposed by laminectomy, and decompressed by aspiration of disc material. Active (n = 13) or sham …(n = 11) stimulators were implanted subcutaneously, with platinum/iridium electrodes sutured to muscle several millimeters above the cord surface, at either end of the laminectomy site. Active stimulators delivered 200 μA of direct current, switching polarity every 15 min, for 3, 6, or 15 weeks. Neurological and electrophysiological examinations were repeated approximately 6 weeks and 6 months after implantation. Few complications were noted. None were attributable to current application. The group of dogs with active stimulators showed greater improvement in function than the group with sham implants, with a trend towards greater recovery in all neurological measures, and evoked potentials. The combined neurological score derived from these separate tests was significantly different from controls at 6 weeks and 6 months (P < 0.05). Application of slowly oscillating electric fields thus appears to be beneficial in the treatment of paraplegia in dogs. Show more

Keywords: Spinal cord, Regeneration, Electric field, Paraplegia, Behavioral recovery, Neurotrauma

DOI: 10.3233/RNN-1993-55601

Citation: Restorative Neurology and Neuroscience, vol. 5, no. 5-6, pp. 305-322, 1993

Authors: Dellon, Evan S. | Crone, Sylvia | Mouery, Robin | Dellon, A. Lee

Article Type: Research Article

Abstract: Measuring human sensibility remains a challenge, with the primary limitation being the instrumentation traditionally available. The Pressure-Specifying Sensory Device (PSD) permits quantitation of the human pressure perception threshold by means of transducers that couple two rounded prongs to a personal computer. If just one prong is perceived in constant contact with the skin, the cutaneous pressure threshold is directly obtained, scaling along a continuum from .05 to 100 g/mm2 (readout on computer monitor). This measurement is analogous to that obtained with the series of Semmes–Weinstein monofilaments (SWM) (readout in logarithmic marking on nylon rod). The present study evaluated twenty …normal volunteers and ten nerve-impaired patients with both the PSD and the SWM. There was a poor correlation between the measurement offeree (r = 0.21) and pressure (r = 0.29) obtained with the PSD and the SWM. This study reaffirms the value of measuring pressure perception threshold during the sensibility evaluation, while calling attention to selection of instrumentation for obtaining this measurement. Show more

Keywords: Sensibility (sensation), Pressure, Threshold, Discrimination, Touch

DOI: 10.3233/RNN-1993-55602

Citation: Restorative Neurology and Neuroscience, vol. 5, no. 5-6, pp. 323-326, 1993

Authors: Guarnieri, T. | Virgili, M. | Villani, L. | Facchinetti, F. | Contestabile, A. | Migani, P.

Article Type: Research Article

Abstract: The excitotoxic brain damage caused by systemic administration of kainic acid requires the activation of N-methyl-D-aspartate (NMDA) receptors in order to fully express its neurotoxic potency. We have tested the relative efficacy of different manipulations of the NMDA receptor on morphological, immunohistochemical and neurochemical parameters in this experimental model. A competitive (CGP 39551) and a non-competitive (MK 801) antagonist of the NMDA receptor, granted full protection against neuronal degeneration and consequent glial proliferation in the hippocampus and olfactory cortex, two regions severely affected by systemic administration of kainic acid. In addition, CGP 39551 completely counteracted the dramatic induction of the …enzyme ornithine decarboxylase which occurs shortly after kainic acid administration. Systemic administration of high amounts of MgSO4 concomitantly and after kainic acid injection, appeared to partially prevent neuronal degeneration but had no clear effects on glial reaction and ornithine decarboxylase induction. Finally administration of an antagonist of the polyamine site present in the NMDA receptor (SL 82.0715), did not appear to have any protective effect at the dose used here. The present results help to better understand the ways by which it could be possible to counteract excitotoxic brain injuries. Show more

Keywords: Excitotoxicity, NMDA receptor antagonist, Polyamine, Neuronal degeneration, Glial reaction, Rat

DOI: 10.3233/RNN-1993-55603

Citation: Restorative Neurology and Neuroscience, vol. 5, no. 5-6, pp. 327-335, 1993

Authors: Senatorov, Vladimir V. | Nyakas, Csaba | Fulop, Zoltan

Article Type: Research Article

Abstract: Fetal cerebral cortical tissue was transplanted into an aspirated lesion cavity made in the sensorimotor cortex of adult rats. Ten weeks after grafting, outgrowing fibers from the graft were visualized by an anterograde tracing technique using Phaseolus vulgaris leucoagglutinin (PHA-L). It was demonstrated that the efferent fibers grew into the neighboring host cortical tissue, the corpus callosum and in some cases approached caudate/putamen. Characteristic axon arborization with abundant boutons were found in the host cortical tissue, but only in close vicinity to the grafts. It is concluded that the PHA-L anterograde tracing technique can be a useful tool to assess …the degree of anatomical integration of the transplants into the host tissue. Show more

Keywords: Neural transplantation, Sensorimotor cortex, Fiber outgrowth, Phaseolus vulgaris leucoagglutinin tracing

DOI: 10.3233/RNN-1993-55604

Citation: Restorative Neurology and Neuroscience, vol. 5, no. 5-6, pp. 337-345, 1993

Authors: Suzumura, Akio | Sawada, Makoto | Mokuno, Kenji | Kato, Kanefusa | Marunouchi, Tohru | Yamamoto, Hiroko

Article Type: Research Article

Abstract: Recent studies have suggested that cytokines, such as interleukin-l(IL-l), tumor necrosis factor(TNF)α, or interferon(IFN) γ, play a role in the development of astrocytic gliosis. In this study, we examined the effects of these cytokines on the proliferation of purified astrocytes in vitro, using the colorimetric assay, bromodeoxyuridine uptake by astrocytes, and changes in the amount of the S-100 β protein as markers of astrocyte proliferation. The effects of a crude supernatant from microglia enriched cultures (Mi-Sup) also were examined. In contrast to previous reports, these recombinant cytokines did not induce proliferation of purified mouse astrocytes. However, stimulation of astrocytes with …Mi-Sup increased all the markers for astrocyte proliferation, which could not be blocked by the addition of anti-IL-1, IL-6, IFNγ or TGFβ antibodies. Thus, it appears that microglia produce factors, other than the above cytokines, which induce the proliferation of astrocytes in vitro. These factors may have a role in the development of gliosis in various pathologic conditions of the central nervous system. Show more

Keywords: Microglia, Astrocyte, Gliosis, Cytokine, Proliferation, Glia, S-100 protein, Bromodeoxyuridine

DOI: 10.3233/RNN-1993-55605

Citation: Restorative Neurology and Neuroscience, vol. 5, no. 5-6, pp. 347-352, 1993

Authors: Keeley, Robert | Atagi, Tanya | Sabelman, Eric | Padilla, Jose | Kadlcik, Paula | Agras, Jean | Eng, Lawrence | Wiedman, Tien-Wen | Nguyen, Khoi | Sudekum, Anthony | Rosen, Joseph

Article Type: Research Article

Abstract: Current methods of peripheral nerve repair are to directly suture cut nerve stumps, or to bridge large gaps with an autograft repair. Autograft-associated problems include donor site morbidity and limited supply. Many of the present limitations of nerve repair might be overcome by expanding the patients own Schwann cells in vitro, then combining the cells with other neuro-tropic and -trophic materials into an Artificial Nerve Graft (ANG) for bridging a nerve gap. In this 4.5 month experiment, a rat peroneal nerve model with a 10 mm gap was used to evaluate the effect of live Schwann cells on peripheral nerve …regeneration. Nerve gaps were repaired with cellular ANGs containing live Schwann cell, dead Schwann cell, or mixed fibroblast/Schwann cell populations suspended in a collagen I matrix, and with sutured autografts or ANGs containing just collagen or medium. Regenerated nerves were evaluated by walking track analysis, qualitative and quantitative histology, and electrophysiology. Overall, the autograft was the best repair method, while the ANG containing live Schwann cells was statistically superior to other ANG repair methods. This study demonstrates that an ANG containing cultured syngeneic Schwann cells improves functional, histological, and electrophysiological parameters of peripheral nerve regeneration. Show more

Keywords: Schwann cell, Collagen type I, Biopolymer, Artificial nerve graft (ANG), Sutured autograft, Peripheral nerve repair, Nerve regeneration

DOI: 10.3233/RNN-1993-55606

Citation: Restorative Neurology and Neuroscience, vol. 5, no. 5-6, pp. 353-366, 1993

Authors: Lalonde, Robert | Joyal, Christian C. | Guastavino, Jean-Marie | Côté, Chantal | Botez, M.I

Article Type: Short Communication

Abstract: The effects of amantadine and ketamine were compared to a placebo in a coat-hanger test on lurcher mutant mice. This test measures motor coordination and is dependent on cerebellar functioning. Both drugs improved motor coordination of the cerebellar mutants in that the time taken to reach the side-bar according to a 2 paw criterion was decreased during the drugged condition in comparison to the non-drugged condition. This result indicates that NMDA receptor antagonists may improve motor coordination in animals with cerebellar disease.

Keywords: Lurcher mutant, Cerebellum, Ketamine, NMDA antagonist

DOI: 10.3233/RNN-1993-55607

Citation: Restorative Neurology and Neuroscience, vol. 5, no. 5-6, pp. 367-370, 1993

Authors: Goldstein, L.B. | MacMillan, V.

Article Type: Research Article

Abstract: Pharmacologic studies have implicated norepinephrine in amphetamine-facilitated motor recovery following sensorimotor cortex injury in rats. We studied the acute effects of unilateral sensorimotor cortex ablation on the release of norepinephrine in cerebellum with in vivo dialysis. In rats without a cortex lesion, the administration of a single dose of d-amphetamine (2.6 mg/kg base weight, i.p.) resulted in a substantial increase in dialyzable norepinephrine in cerebellum reaching its peak 30–40 min later (∼ 14 pg/μl, not corrected for recovery). The administration of the same dose of d-amphetamine to rats 60 min following a suction-ablation lesion of the right sensorimotor cortex did …not result in norepinephrine release into the cerebellar dialysates. These data provide evidence for an acute remote effect of sensorimotor cortex injury on amphetamine-induced norepinephrine release in the cerebellum (diaschisis). Show more

Keywords: Diaschisis, Norepinephrine, Sensorimotor cortex, Cerebellum, Microdialysis, Rat

DOI: 10.3233/RNN-1993-55608

Citation: Restorative Neurology and Neuroscience, vol. 5, no. 5-6, pp. 371-376, 1993

Article Type: Research Article

DOI: 10.3233/RNN-1993-55609

Citation: Restorative Neurology and Neuroscience, vol. 5, no. 5-6, pp. 377-385, 1993