Restorative Neurology and Neuroscience - Volume 6, issue 1

Authors: Sekerková, Gabriela | Malatová, Želmíra | Orendáčová, Judita | Žigová, Tatiana

Article Type: Research Article

Abstract: We have transplanted encapsulated dorsal root ganglia (DRG) from adult Wistar albino rats unilaterally into partially bulbectomized (n = 20) neonatal (P3–5) rats of the same strain. Three months postoperatively the animals were perfused and their brains processed by direct thiocholine method for cholinesterases (Ch), specific acetylcholinesterase (AChE) and nonspecific butyrylcholinesterase (BuChE) or stained by Cresyl violet. Selected sections were immunohistochemically stained for olfactory marker protein (OMP). In 17 cases we found surviving transplanted DRG. Fifteen transplants were well integrated with the spared portion of the olfactory bulb (OB) as clearly demonstrated by AChE and BuChE histochemistry, while two did …not integrate. Regenerated OMP positive olfactory axons originating from neuroepithelium and AChE positive fibres from OB remnant penetrated into the transplants. In one case, fibers connected with BuChE positive Schwann cells grew from the transplanted DRG into the host OB. Individual sensory neurons of the transplants revealed variable intensity of the AChE staining, thus resembling the pattern of AChE activity in normal DRG. BuChE activity was mostly localized on the surface of sensory neurons in the ring of satellite cells. Some BuChE positive blood vessels penetrated into the DRG, and were observed around sensory neurons. The results showed a considerable viability and adaptability of the sensory neurons in the new environment after a long-term transplantation. Show more

Keywords: Acetylcholinesterase, Butyrylcholinesterase, Dorsal root ganglion, Olfactory bulb, Rat, Transplantation

DOI: 10.3233/RNN-1993-6101

Citation: Restorative Neurology and Neuroscience, vol. 6, no. 1, pp. 1-8, 1993

Authors: Plumet, Jocelyne | Ebrahimi, Afsaneh | Guitet, José | Roger, Michel

Article Type: Research Article

Abstract: We have studied the effect of transplantation of embryonic frontal cortex on the motor deficit resulting from motor cortex lesion in the adult rat. Twenty-four 2-month-old rats were first trained in a food reaching task with right and left forelimbs. Then, at 4 months of age, the subjects were divided into two equal groups. In the lesion group, the animals sustained a lesion of the left motor cortex, whereas in the graft group the animals received a fetal cell suspension of embryonic (E16) frontal cortical tissue three days after the lesion. Postoperative reaching ability was assessed every week during eight …weeks and then every two months until the age of one year. The results indicate that the deficit resulting from the lesion is bilateral but mainly affects the limb contralateral to the lesion. During the first 3 weeks of postoperative testing, both groups displayed comparable evolution of performance with contralateral forelimb, characterized by an initial large drop followed by progressive recovery. But, whereas in the lesion group performance did not increase after the fourth postoperative week, in the graft group the reaching scores further improved, without recovering, however, preoperative levels. This improvement was still observed eight months after transplantation. However, no improvement appeared using the limb ipsilateral to the transplant. An anatomical study of the volumes of transplant and/or lesion revealed that the importance of the recovery or deficit varied as a function of the sizes of the transplant and/or lesion within the rostral part of the motor cortex, approximately corresponding to the rostral forelimb area of Neafsey et al. [37]. It is therefore suggested that in adult rats, some components of the motor deficit resulting from a lesion of the motor cortex can be partially reduced by transplantation of homotopic embryonic cortex. Show more

Keywords: Adult lesion, Neurotransplantation, Motor cortex, Recovery, Longitudinal study, Skilled forelimb use, Cortical location, Rat

DOI: 10.3233/RNN-1993-6102

Citation: Restorative Neurology and Neuroscience, vol. 6, no. 1, pp. 9-27, 1993

Authors: Cho, Eric Yu Pang | So, Kwok-Fai

Article Type: Research Article

Abstract: It is a well known fact that the proximity of an axonal lesion from the cell body influences the degree of neuronal survival: a lesion close to the cell body leads to more severe cell death and vice versa. On the other hand, experiments involving transplantation of a peripheral nerve (PN) to various central nervous system (CNS) regions to induce axonal regeneration have suggested that axonal regrowth is more vigorous when the grafting is performed closer to the cell body. It is not clear, however, whether it is the distance of the site of axotomy or the location of the …trophic source (PN graft) or both from the cell body which dictates the vigorousness of axonal regrowth. Using either a model of transplantation of a PN to the retina or implantation of a short PN into the vitreous body of the eye of the adult hamster, we have demonstrated that sprouting of axon-like processes from retinal ganglion cells (RGCs) depends on the distance of axotomy from the cell body when the PN graft is maintained at a constant distance from the cell body. Moreover, it was found that the distance of axotomy at which sprouting of axon-like processes could be induced was different for the 2 paradigms: with the intravitreal PN model, sprouting was observed even after intracranial ON cut whereas it was absent in the PN grafting-to-retina paradigm. This suggests that extrinsic influence (in this case an intravitreal PN) can overcome to a certain extent the growth-suppressive effects due to a long distance of axotomy. Show more

Keywords: Retinal ganglion cell, Peripheral nerve graft, Intravitreal graft, Axon-like process, Axotomy

DOI: 10.3233/RNN-1993-6103

Citation: Restorative Neurology and Neuroscience, vol. 6, no. 1, pp. 29-34, 1993

Authors: Ulenkate, H.J.L.M. | Verhaagen, J. | Plantinga, L.C. | Mercken, M. | Veldman, H. | Jennekens, F.G.I. | Gispen, W.H. | Oestreicher, A.B.

Article Type: Research Article

Abstract: Crush or transection of peripheral nerves of the adult rat is accompanied by changes in protein expression, including the growth associated protein (GAP-43) B-50. Following peripheral nerve crush in rat enhanced B-50 immunoreactivity was observed in regenerating nerve fibres and in newly formed axon terminals. However, before reinnervation was apparent, an unexpected transient increase in B-50 immunoreactivity was observed at denervated motor endplates [J. Neurosci. 8 (1988) 1759]. This study was performed to clarify this observation. Four days following facial nerve crush B-50 immunoreactivity was detected by double immunofluorescence microscopy in Sl00-positive Schwann cells covering the denervated endplates. Using diluted …polyclonal and monoclonal B-50 antibodies we found that B-50 immunoreactivity at the denervated motor endplates was strongly increased in comparison to innervated motor endplates in which B-50 immunoreactivity was hardly detectable. However, when a high concentration of B-50 antibodies was applied the normal innervated motor endplates were also B-50 immunoreactive. Muscle fibres did not display B-50 immunoreactivity. Northern blot analysis revealed elevated B-50 mRNA in denervated muscle and in degenerating nerve with respect to the controls. The B-50 mRNA levels in these non-neuronal tissues were very low compared to the intact and injured facial nucleus containing the neuronal cell bodies. Electron microscopy demonstrated that the B-50 protein was localized in the processes of Schwann cells covering axon terminals of intact and vacant motor endplates and in axon varicosities of sympathetic nerves. This study has confirmed that prior to reinnervation B-50 immunoreactivity is increased at denervated motor endplates and shows that B-50 is co-localized with S100 in Schwann cells. Therefore, upregulation of B-50 expression in Schwann cells may explain the early occurrence of B-50 immunoreactivity at the motor endplate. Show more

Keywords: Glia, Neuromuscular junction, Neuron–glia contact, Ultrastructure

DOI: 10.3233/RNN-1993-6104

Citation: Restorative Neurology and Neuroscience, vol. 6, no. 1, pp. 35-47, 1993

Authors: Hori, Yozo | Kageyama, Hiroyasu | Kihara, Tsuyoshi | Ikeda, Masato | Nakano, Akira | Kurosawa, Atsushi

Article Type: Research Article

Abstract: The effects of striatal transplantation of PC12 cells on amphetamine-induced rotational behavior and monoamine levels were examined in rats with unilateral 6-hydroxydopamine (6-OHDA) lesions in the nigrostriatal pathway. A total of 9 × 104 or 9 × 105 cells of PC12 was implanted into 3 sites in the striatum and changes in amphetamine (3 mg/kg, i.p.)-induced rotational behavior were observed for 8 weeks. Two weeks after transplantation, a significant reduction in rotation was observed. However, this improvement disappeared after 3 weeks. Three of 7 rats implanted with 9 × 104 cells and 6 of 7 rats with …9 × 105 cells died between 3 and 4 weeks after transplantation. In 6-OHDA-injected control rats, the levels of dopamine (DA) and its metabolites 3,4-dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA) in brain dialysates were profoundly reduced to between 0 and 11% of normal rats, while the serotonin metabolite 5-hydroxyindoleacetic acid (5-HIAA) level remained unchanged. These reductions in DA and its metabolites did not recover at 2 or 8 weeks after the transplantation of 9 × 104 PC12 cells. 5-HIAA was reduced at 2 weeks and recovered to nearly control levels at 8 weeks. Histologically, PC12 cells proliferated to form a large tumor mass at 2 weeks. There were almost no processes growing from the aggregated PC12 cells into the host tissue. These results indicate that PC12 grafts do not release detectable quantities of DA into the deafferented striatum, and suggest that the transient improvements in rotational behavior may be due to a non-specific suppression in neuronal function induced by the growing tumor mass. Show more

Keywords: PC12 cell, Transplantation, Rotational behavior, 6-OHDA, Dopamine, Microdialysis

DOI: 10.3233/RNN-1993-6105

Citation: Restorative Neurology and Neuroscience, vol. 6, no. 1, pp. 49-55, 1993

Authors: Lewin-Kowalik, Joanna | Koksanowicz, Ewa | Barski, Jarosław-Jerzy | Krause, Mieczysław | Górka, Dariusz | Gołka, Beata | Kwiek, Stanisław

Article Type: Research Article

Abstract: The aim of the present paper was to ascertain whether experimental hyperthyroidism promotes the regenerative action of predegenerated peripheral nerve grafts implanted into the transected hippocampus. Hyperthyroidism was induced by subcutaneous injections of T4 . Autologous peripheral nerve grafts were implanted immediately, 7 and 35 days following transection of the sciatic nerve. Cells extending their neurites into the grafts were traced by means of horseradish peroxidase conjugated with fluoresceine isothiocyanate (FITC-HRP). Fluorescence microscope examination revealed that experimentally induced hyperthyroidism considerably enhanced the regenerative influence of peripheral nerve grafts. This effect was particularly pronounced in hyperthyrotic animals treated with either nonpredegenerated …or 35 day predegenerated nerve grafts. Show more

Keywords: Sciatic nerve autograft, Hyperthyroidism, Predegeneration, Neurite outgrowth, Hippocampus

DOI: 10.3233/RNN-1993-6106

Citation: Restorative Neurology and Neuroscience, vol. 6, no. 1, pp. 57-63, 1993

Authors: Hattori, Satoshi | Li, Qianming | Matsui, Nobuo | Nishino, Hitoo

Article Type: Research Article

Abstract: To evaluate the physiological role of striatal dopamine (DA) during exercise and the mechanism of functional recovery mediated by grafted DAergic neurons, the locomotor ability (treadmill running) and DA turnover were investigated using treadmill running combined with in vivo microdialysis in the intact control rats, 6-hydroxydopamine (6-OHDA) lesioned rats (hemi-parkinsonian model rats) and DAergic cell grafted rats. The 3 groups of rats were trained to run on a straight treadmill at a speed of 1,800 cm/min for 20 min every day for 7 consecutive days. If the rats could not follow the speed they got electrostimulation (ES) from the grid …behind the treadmill belt. The numbers of ES rats received during treadmill running were counted to quantify the locomotor ability. Control rats could keep up with the treadmill easily (0–1 ES/10 min), whereas lesioned rats could not follow the speed (80–100 ES/10 min). Most of the grafted rats received only a few ES, but a few received over 100 ES/10 min. Extracellular DA and its metabolites, dihydroxyphenyl acetic acid (DOPAC) and homovanillic acid (HVA), were measured by in vivo microdialysis and high-performance liquid chromatography (HPLC) during and after treadmill running. In control rats the basal levels of DA, DOPAC and HVA were 2.3 fmol/μl, 1,109.8 fmol/μl and 612.2 fmol/μl, respectively. They increased up to 130%, 140% and 160% by running. In 6-OHDA lesioned rats basal values of DA, DOPAC and HVA were less than 10% of controls. We did not perform microdialysis in these rats since they got too much ES during running. In grafted rats that showed good recovery in locomotor ability, DA returned to almost control level (1.9 fmol/μl), but those of DOPAC (127.8 fmol/μl) and HVA (100.2 fmol/μl) were still low. DA, DOPAC and HVA increased up to 130%, 130% and 150% by running in a similar pattern as in intact rats. These results suggest that grafted neurons can release and metabolize DA in the host striatum both tonically and phasically in relation with internal and external stimuli and also suggest that treadmill running ability is a good indicator of DA turnover in the striatum. Thus, the treadmill running test with microdialysis is useful for quantitative evaluation of motor function in grafted animals. Show more

Keywords: Treadmill running, 6-OHDA lesion, Neural transplantation, Dopamine, Locomotion, Microdialysis

DOI: 10.3233/RNN-1993-6107

Citation: Restorative Neurology and Neuroscience, vol. 6, no. 1, pp. 65-72, 1993

Authors: Yoshimoto, Yusuke | Date, Isao | Ohmoto, Takashi

Article Type: Research Article

Abstract: Techniques to maintain viable fetal neural tissue might be an important tool for a successful neural transplantation by giving enough time for preparation, storage, and transportation of donor tissue. In the present study, we examined the effect of freeze-storage (cryopreservation) for 7 days at liquid nitrogen temperature on the survivability of intraventricular rat fetal mesencephalic grafts (gestational day 15) when using 10% dimethyl sulfoxide (DMSO), 0.1% methylcellulose, or 10% DMSO with additional 0.1% methylcellulose (m-DMSO) as a cryoprotective agent. As a control group, the survivability of grafts transplanted immediately after dissection was examined. The volume of grafts treated with m-DMSO …was 3 times as large as that of grafts treated with 10% DMSO alone. While the number of surviving neurons in 10% DMSO-treated transplants decreased down to 15% of the control value, there was no statistically significant difference in the number of surviving neurons between the m-DMSO treated group and control group. In the group treated with m-DMSO, there were a lot of well developed tyrosine hydroxylase positive neurons and fibers in the graft, and a few reactive astrocytes were observed only in the peripheral region of the grafts. In the group treated with 0.1% methylcellulose alone, no graft survival was observed in any of the animals. We conclude that the addition of methylcellulose to the commonly used cryoprotective agent (DMSO) is beneficial for the freeze-storage of fetal neural tissue. Show more

Keywords: Cryopreservation, Methylcellulose, DMSO, Neural transplantation

DOI: 10.3233/RNN-1993-6108

Citation: Restorative Neurology and Neuroscience, vol. 6, no. 1, pp. 73-81, 1993