Restorative Neurology and Neuroscience - Volume 5, issue 4

Authors: Hongpaisan, Jarin | Molander, Carl

Article Type: Research Article

Abstract: The distribution of stimulus evoked Fos protein-like immunoreactivity in spinal cord neurons was studied in adult rats at different survival times after sciatic nerve crush or transection and epineural repair. Fos protein-like immunoreactivity was induced either by electrical stimulation of the sciatic nerve central to the injury, at C-fiber strength, at 21, 39, and 92 days post-lesion, or by noxious heat applied to the skin of the hind paw 92 days post-lesion. The contralateral uninjured side served as control. The results with electrical stimulation showed, with some exceptions, that the distribution of c-fos expressing cells in the spinal cord on …the normal and on the previously injured side were similar after both crush and transection with repair. The main finding was an up-regulation of the number of Fos protein immunoreactive neurons in the inner portion of Rexed's lamina II. The results following heat stimulation 92 days post-lesion showed a decrease in the number of labeled neurons in most laminae after both types of injury. This was more pronounced in cases with sciatic nerve transection with repair compared to cases with crush. The results indicate time-dependent alterations in the distribution of stimulus evoked c-fos expression in spinal cord neurons during regeneration after nerve injury. Furthermore, the results from heat stimulation may indicate a slower and perhaps more incomplete restoration process after transection with repair than after crush. Show more

Keywords: Spinal cord, c-fos, Nerve regeneration, Sciatic nerve, Immediate early gene, Nerve injury

DOI: 10.3233/RNN-1993-5401

Citation: Restorative Neurology and Neuroscience, vol. 5, no. 4, pp. 249-261, 1993

Authors: Dunnett, S.B. | Wareham, A.T. | Torres, E.M.

Article Type: Research Article

Abstract: In a previous study we evaluated the conditions under which septal grafts could ameliorate performance of rats with fimbria-fornix lesions in an operant differential reinforcement of low rates of responding (DRL) task. Although the best recovery was demonstrated by the group in which the grafts were made 10 days following the lesion surgery, this factor (lesion-graft interval) was confounded with the developmental stage of the donor tissue, and it was suggested that the age of the embryonic donor was a more significant factor than the lesion graft interval in achieving good recovery. The present study provides a better control of …embryonic age of the donor tissues, and we report that cholinergic rich septal grafts implanted into the host hippocampus either immediately or 11 days following fimbria-fornix lesion yielded better recovery than when the grafts were implanted after longer (8 weeks) lesion-graft intervals. In addition, grafts implanted into the intact hippocampus were without significant effect when the host rats were subjected to a delayed fimbria-fornix lesion made 10 weeks after graft implantation. These results corroborate the hypothesis of Nieto-Sampedro, Manthorpe and colleagues that ‘wound-derived neurotrophic factors’ can promote the functional viability of embryonic septal grafts in the hippocampus, even if such factors are not absolutely necessary for graft survival. Show more

Keywords: Septal graft, Hippocampus, Cholinergic system, DRL, Trophic factor

DOI: 10.3233/RNN-1993-5402

Citation: Restorative Neurology and Neuroscience, vol. 5, no. 4, pp. 263-274, 1993

Authors: Tomatsuri, Masaki | Okajima, Seiichiro | Ide, Chizuka

Article Type: Research Article

Abstract: 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. Show more

Keywords: Sprout formation, Node of Ranvier, Subaxolemmal undercoat, Peripheral nerve regeneration, Crushed by ligation, Rat sciatic nerve

DOI: 10.3233/RNN-1993-5403

Citation: Restorative Neurology and Neuroscience, vol. 5, no. 4, pp. 275-282, 1993

Authors: Boyeson, Michael G. | Krobert, Kurt A. | Scherer, Paul J. | Grade, Charles M.

Article Type: Research Article

Abstract: Previous research has indicated that antagonists of locus ceruleus functioning, when administered during the acute phase of an injury, slow recovery of motor function following unilateral sensorimotor cortex injury. Following a recovery plateau in animals, it is possible to pharmacologically reinstate unilateral motor deficits in recovered animals with similar acting drugs given intraperitoneally. The present study was designed to localize the brain systems responsible for the reinstatement of the deficit after recovery from the cortical injury. The results indicate that maintaining functional recovery after injury is modulated by NE in the cerebellum contralateral to the injury, since microinfusions of phenoxybenzamine …into this structure reinstate motor deficits. Additionally, removal of the noradrenergic projection to contralateral cerebellum through unilateral lesions of the locus ceruleus reinstate unilateral deficits more severely than the drug administration. Show more

Keywords: Cerebellum, Norepinephrine, Alpha adrenergic, Locus ceruleus, Sensorimotor cortex, Brain injury, Recovery of function

DOI: 10.3233/RNN-1993-5404

Citation: Restorative Neurology and Neuroscience, vol. 5, no. 4, pp. 283-290, 1993

Authors: Hoffmann, C.F.E. | Marani, E. | Oestreicher, A.B. | Thomeer, R.T.W.M.

Article Type: Research Article

Abstract: The results of unilateral ventral root avulsions at the cervical 7 (C7) level were compared using light microscopy with unilateral transactions of the ventral root C7 at the surface of the cat spinal cord after survival times ranging from one to 90 days. Sections were stained for Nissl, acetylcholinesterase, neurofilaments, glial fibrillary acidic protein, and B-50/GA P43. A distinct difference in neuronal reaction was found between the effects of avulsion and transection of ventral root C7. After avulsion, changes in the Nissl-and acetylcholinesterase-stained sections and the sections stained with antibodies against neurofilaments remained present up to 90 days, although the …number of neurons in the ventral horn on the avulsed side had significantly decreased at 60 and 90 days. This was in contrast to the transection where the changes in the stainings tended to return to the normal situation between 30 and 60 days and showed the normal pattern 90 days after transection. No decrease in the number of neurons was found. Both lesions were situated in the transitional region of the nerve roots. After avulsion axons break in the white matter of the CNS, while the axons were transected in the PNS compartment of the CNS-PNS transitional region. After avulsion, not only were the axons disconnected, as in transection, but the connections of recurrent motor axon collaterals probably were damaged. This may explain the different reaction after avulsion and transection. Show more

Keywords: Avulsion, Transection, Ventral root, Brachial plexus, Motoneuron

DOI: 10.3233/RNN-1993-5405

Citation: Restorative Neurology and Neuroscience, vol. 5, no. 4, pp. 291-302, 1993

Authors: Pritzel, Monika

Article Type: Book Review

DOI: 10.3233/RNN-1993-5406

Citation: Restorative Neurology and Neuroscience, vol. 5, no. 4, pp. 303-303, 1993