Recent studies demonstrate that rehabilitation ameliorates physical and cognitive impairments of patients with stroke, spinal cord injury, and other neurological diseases and that rehabilitation also has potencies to modulate brain plasticity. Here we examined the effects of compulsive exercise on Parkinson's disease model of rats. Before 6-hydroxydopamine (6-OHDA, 20 microg) lesion into the right striatum of female SD rats, bromodeoxyuridine (BrdU) was injected to label the proliferating cells. Subsequently, at 24 h after the lesion, the rats were forced to run on the treadmill (5 days/week, 30 min/day, 11 m/min). As behavioral evaluations, cylinder test was performed at 1, 2, 3, and 4 weeks and amphetamine-induced rotational test was performed at 2 and 4 weeks with consequent euthanasia for immunohistochemical investigations. The exercise group showed better behavioral recovery in cylinder test and significant decrease in the number of amphetamine-induced rotations, compared to the non-exercise group. Correspondingly, significant preservation of tyrosine hydroxylase (TH)-positive fibers in the striatum and TH-positive neurons in the substantia nigra pars compacta (SNc) was demonstrated, compared to the non-exercise group. Additionally, the number of migrated BrdU- and Doublecortin-positive cells toward the lesioned striatum was increased in the exercise group. Furthermore, brain-derived neurotrophic factor and glial cell line-derived neurotrophic factor increased in the striatum by exercise. The results suggest that exercise exerts neuroprotective effects or enhances the neuronal differentiation in Parkinson's disease model of rats with subsequent improvement in deteriorated motor function.

These results suggest that electric stimulation prevents apoptosis through the phosphoinositide 3-kinase pathway. Consequently, the ischemic brain might have been rendered as a nurturing microenvironment characterized by robust angiogenesis and diminished microglial/astrocytic proliferation, resulting in the reduction of infarct volumes and behavioral recovery. Electric stimulation is a novel and potent therapeutic tool for cerebral ischemia.

Background: Parkinson's disease (PD) is a neurological disorder characterized by the degeneration of nigrostriatal dopaminergic systems. Free radicals induced by oxidative stress are involved in the mechanisms of cell death in PD. This study clarifies the neuroprotective effects of edaravone (MCI-186, 3-methyl-1-phenyl-2-pyrazolin-5-one), which has already been used for the treatment of cerebral ischemia in Japan, on TH-positive dopaminergic neurons using PD model both in vitro and in vivo. 6-hydroxydopamine (6-OHDA), a neurotoxin for dopaminergic neurons, was added to cultured dopaminergic neurons derived from murine embryonal ventral mesencephalon with subsequet administration of edaravone or saline. The number of surviving TH-positive neurons and the degree of cell damage induced by free radicals were analyzed. In parallel, edaravone or saline was intravenously administered for PD model of rats receiving intrastriatal 6-OHDA lesion with subsequent behavioral and histological analyses.

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Deep brain stimulation (DBS) is used to treat a variety of neurological disorders including Parkinson's disease. In this study, we explored the effects of striatal stimulation (SS) in a rat model of chronic-phase ischemic stroke. The stimulation electrode was implanted into the ischemic penumbra at 1 month after middle cerebral artery occlusion (MCAO) and thereafter continuously delivered SS over a period of 1 week. Rats were evaluated behaviorally coupled with neuroradiological assessment of the infarct volumes using magnetic resonance imaging (MRI) at pre- and post-SS. The rats with SS showed significant behavioral recovery in the spontaneous activity and limb placement test compared to those without SS. MRI visualized that SS also significantly reduced the infarct volumes compared to that at pre-SS or without SS. Immunohistochemical analyses revealed a robust neurogenic response in rats that received SS characterized by a stream of proliferating cells from the subventricular zone migrating to and subsequently differentiating into neurons in the ischemic penumbra, which exhibited a significant GDNF upregulation. In tandem with this SS-mediated neurogenesis, enhanced angiogenesis was also recognized as revealed by a significant increase in VEGF levels in the penumbra. These results provide evidence that SS affords neurorestoration at the chronic phase of stroke by stimulating endogenous neurogenesis and angiogenesis.

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Parkinson's disease (PD) is characterized by degeneration of nigrostriatal dopaminergic neuronal systems. Several therapeutic tools for PD include medication using L-DOPA and surgeries such as deep brain stimulation are established. However, the therapies are considered as symptomatic therapy, but not basic remedy for PD and a new regenerative therapy would be desired to explore. In this study, the neuroprotective/rescue effects of erythropoietin (EPO), a well known hematopoietic hormone, on dopaminergic neurons were explored with neurogeneic potencies of EPO. EPO (100 IU/day) was continuously administered with micro-osmotic pump for a week to PD model of rats induced by intrastriatal 6-hydroxydopamine (6-OHDA) injection with subsequent behavioral and immunohistochemical investigations. The number of amphetamine-induced rotations of EPO-treated rats significantly decreased, compared to the control rats. The preservation of dopaminergic neurons of EPO-treated rats were confirmed by tyrosine hydroxylase staining and Fluoro-Gold staining. The number of bromodeoxyuridine (BrdU)/polysialic acid-neural cell adhesion molecule (PSA-NCAM) double positive cells in the subventricular zone of EPO treated rats significantly increased with migratory potencies to the damaged striatum,compared to the control rats. Furthermore, TUNEL staining and phosphorylated Akt staining revealed that the neuroprotective/rescue effects of EPO might be mediated by anti-apoptotic effects through the increase of phosphorylated Akt. These results suggest that continuous low dose infusion of EPO exerts neuroprotective/rescue effects with neurogeneic potentials. EPO might be a strong tool for PD therapy, although the further experiments should be added.

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