Restorative Neurology and Neuroscience - Volume 3, issue 4

Authors: Weil, Stuart M. | Madison, Roger D. | Crutcher, Keith A.

Article Type: Research Article

Abstract: Synthetic porous collagen tubes were implanted into the rat fimbria in order to determine whether such prostheses will permit axonal growth in the mature mammalian central nervous system (CNS). The tubes were found to slowly degrade over 4 weeks. In the majority of cases a distinct tissue core occupied the lumen of the tube and extended from the rostral (septal) end to the caudal (hippocampal) end. The core consisted of cellular aggregates of various cell types and blood vessels. In addition, the presence of axons within the tube lumen was demonstrated at both light and electron microscopic levels. Fibers within …the tubes were visualized with noradrenergic histofluorescence and with neurofilament immunohistochemistry. Pretreatment of the tubes with nerve growth factor (NGF) resulted in circumferential disposition of the tissue core and an increase in acetylcholinesterase activity associated with the tube but no obvious change in axonal regeneration. No evidence was obtained for reinnervation of the hippocampal formation by cholinergic or noradrenergic fibers. These results indicate that porous collagen tubes will persist for several weeks within the mature rat CNS and can support axonal growth. Show more

Keywords: Collagen nerve guide, Regeneration, Nerve growth factor, Septohippocampal pathway, Hippocampus, Prosthesis, Central nervous system

DOI: 10.3233/RNN-1991-3401

Citation: Restorative Neurology and Neuroscience, vol. 3, no. 4, pp. 167-175, 1991

Authors: Mendoza-Ramírez, José-Luis | Aguilar-Roblero, Raúl | Zainos-Rosales, Antonio | Drucker-Colín, René

Article Type: Research Article

Abstract: Motor asymmetries as well as changes in the density of postsynaptic dopamine receptors produced by unilateral denervation of the striatum have been reduced by both substantia nigra (SN) and adrenal medullary (AM) grafts. Since to this date all studies have placed the grafts on the side ipsilateral to the lesion, the purpose of this study was to determine whether similar effects can be obtained when grafts are placed contralateral to the denervated side. The results of this study showed that 6-hydroxydopamine-lesioned rats followed up to 150 days with contralaterally placed intraventricular fetal substantia nigra grafts and fetal adrenal medulla grafts …have a reduction of turning behavior of 41% and 34% respectively. However, contrary to ipsilateral grafts no normalization of dopamine receptor density as measured by [3 H]spiperone autoradiography was observed 6 months after SN grafts, however, after AM grafts normalization did occur except in the anterior portion of the striatum. These results suggest that the compensatory motor changes induced by the grafted tissues could be mediated by mechanisms unrelated to changes in receptor density. Show more

Keywords: Nigrostriatal pathway, Graft, Dopamine, Adrenal medulla, Substantia nigra, Autoradiography

DOI: 10.3233/RNN-1991-3402

Citation: Restorative Neurology and Neuroscience, vol. 3, no. 4, pp. 177-185, 1991

Authors: Becker, Jill B. | Ariano, Marjorie A.

Article Type: Research Article

Abstract: Grafts of fetal ventral mesencephalon/substantia nigra cell suspensions into the dopamine-denervated striatum have been shown to reduce many of the behavioral alterations associated with striatal dopamine depletion. In this report, the behavioral response to amphetamine, apomorphine, the D1 receptor agonist SKF82958, and the D2 receptor agonist LY171555 were tested before and after intrastriatal grafts of fetal substantia nigra, of fetal striatum or no implantation procedure in animals with unilateral dopamine denervation. Grafts of fetal substantia nigra tissue were associated with significant behavioral recovery, as indicated by decreased turning induced by amphetamine (P ≤ 0.005), SKF82958 (P < 0.005), …and LY171555 (P < 0.002). These effects were significantly different from the response in animals that did not receive grafts (P < 0.05) and occurred in the absence of decreased apomorphine-induced turning. These data suggest that the response to selective D1 or D2 dopamine receptor agonists is diminished following grafts of fetal dopaminergic tissue and that this behavioral effect is dissociable from the phenomena of behavioral supersensitivity to apomorphine. In a subset of substantia nigra grafted animals, it was found that D1 or D2 dopamine receptor antagonists administered 30 min prior to apomorphine could significantly reduce apomorphine-induced turning. Show more

Keywords: Parkinson's disease, Fetal tissue graft, SKF82958, LY171555, Amphetamine, Apomorphine, Rotational behavior

DOI: 10.3233/RNN-1991-3403

Citation: Restorative Neurology and Neuroscience, vol. 3, no. 4, pp. 187-195, 1991

Authors: Raymond, J. | Ez-Zaher, L. | Demêmes, D. | Lacour, M.

Article Type: Research Article

Abstract: The synaptic density in the medial vestibular nuclei of the cat was analyzed after section of the ipsilateral vestibular nerve, using an anti-synaptophysin antibody as a nerve terminal marker. Synaptic areas of nuclei ipsilateral (test) and contralateral (control) to the lesion were measured to quantify synaptic loss (one week post-lesion) and synaptic site reoccupation during vestibular compensation (3 weeks and 5 months post-lesion). The results indicate that only 35% of the immunoreactive synaptic profiles in the media) vestibular nucleus were due to vestibular nerve input: the mean synaptic profile loss in the deafferented nucleus one week post-lesion was 35.25% (± …13.83). This loss was rapidly compensated overtime since it was reduced to 14% (± 13.25) 3 weeks post-lesion, corresponding to a synaptic restoration of approximately 60%. The synaptic density in the deafferented nucleus 5 months after neurectomy was not significantly different from that of the intact vestibular nuclei. These results suggest that vestibular neurectomy is followed by an axonal sprouting in the partially deafferented medial vestibular nuclei, which raises the question concerning the origins and the functional role of the new axon terminals in vestibular compensation. Show more

Keywords: Vestibular compensation, Immunocytochemistry, Sprouting, Synaptophysin, Medial vestibular nucleus, Cat, Unilateral vestibular neurectomy

DOI: 10.3233/RNN-1991-3404

Citation: Restorative Neurology and Neuroscience, vol. 3, no. 4, pp. 197-203, 1991

Authors: Carlstedt, T. | Aldskogius, H. | Rosario, C.

Article Type: Short Communication

Abstract: After dorsal root ganglionectomy in adult rats, the dorsal root was cut close to the spinal cord and implanted into the dorsal horn. Outgrowth from neurons in he dorsal horn of the spinal cord into the implanted dorsal root could be demonstrated after 3 months by means of retrograde HRP labeling. Double-labeling experiments showed that some of these neurons had retained their central projections while extending new processes into the implanted root. The possibility to reconstruct the sensory pathway by replacing the damaged primary sensory neuron with peripheral outgrowth from secondary sensory neurons is discussed.

Keywords: Spinal nerve root, Regeneration, Sensory neuron, Implantation Axon, Labeling, Dorsal horn, Dorsal root

DOI: 10.3233/RNN-1991-3405

Citation: Restorative Neurology and Neuroscience, vol. 3, no. 4, pp. 205-209, 1991

Authors: Zhou, Feng C. | Pu, Cun-Feng | Finger, Stanley

Article Type: Research Article

Abstract: The present experiment was conducted to see whether nimodipine, a calcium channel blocker with the potential to protect vulnerable neurons, could improve the survival rate of striatal grafts under suboptimal conditions. The drug markedly improved graft viability of rats with near-term (E21) striatal implants. Untreated rats showed no surviving neurons while all treated rats showed surviving grafts rich in neuron. It did not affect the survival of striatal grafts from E14/15 donors into the striatum, in which the high rates of survival are normally obtained.

Keywords: Calcium channel blocker, Nimodipine, Graft, Brain transplant, Striatum, Neurotoxicity, Trauma

DOI: 10.3233/RNN-1991-3406

Citation: Restorative Neurology and Neuroscience, vol. 3, no. 4, pp. 211-215, 1991

Authors: Rosenstein, Jeffrey M.

Article Type: Book Review

DOI: 10.3233/RNN-1991-3407

Citation: Restorative Neurology and Neuroscience, vol. 3, no. 4, pp. 217-218, 1991

Article Type: Research Article

DOI: 10.3233/RNN-1991-3408

Citation: Restorative Neurology and Neuroscience, vol. 3, no. 4, pp. 219-225, 1991