No abstract available.
Animals ; Neurons* ; Oxidopamine* ; Rats* ; Substantia Nigra*

No abstract available.
Animals ; Immunohistochemistry* ; Neurons* ; Rats* ; Substantia Nigra*

Parkinson disease (PD) is a neurodegenerative disease characterized by the selective loss of dopaminergic neurons from the substantia nigra pars compacta leading to the impairment of motor functions. Recent genetic studies have uncovered several genes involved in inherited forms of the disease. These gene products are likely to be implicated in the biochemical pathways underlying the etiology of sporadic PD. Our review discusses the pathogenetic mechanisms of the mutated genes.
Dopaminergic Neurons ; Genetics ; Neurodegenerative Diseases ; Parkinson Disease* ; Substantia Nigra

OBJECTIVE: The purpose of this study is to investigate the effect of ipsilateral subthalamic nucleus(STN) lesioning on the spontaneous behavioral changes and the alteration of neuronal activities of deep cerebral nuclei in the rat parkinsonian model with 6-hydroxydopamine(6-OHDA). METHODS: To identify the spontaneous behavioral changes, apomorphine-induced rotational test and forepaw adjusting step were performed. We subsequently investigated the alteration of neuronal activities in the substantia nigra pars reticulata(SNpr) and globus pallidus(GP), in order to compare them with the behavioral changes in rat parkinsonian models. RESULTS: The STN lesioning in the rat parkinsonian model clearly improved behavioral changes. Compared to the normal control rats, rat PD models exhibited a significant increase in mean firing rates and the percentage of bursting neurons in the STN and SNpr. In the STN-lesioned rat PD models, mean firing rates and the percentage of bursting neurons in the SNpr were reduced and those in the GP increased. CONCLUSION: STN lesioning induced behavior improvement in rat parkinsonian models seems to be consistent with the surgical outcomes of the STN stimulation therapy in advanced Parkinsonn's disease(PD). The alteration of the neuronal activities in the SNpr and GP suggests that these sites are responsible for the improvement of parkinsonian motor symptoms observed following STN lesioning in rat parkinsonian models. The significance of bursting activity in the SNpr and GP remains obscure. Further study is necessary to elucidate the pathophysiological mechanism of PD.
Animals ; Fires ; Globus Pallidus ; Kainic Acid* ; Neurons* ; Oxidopamine* ; Parkinson Disease ; Rats* ; Substantia Nigra ; Subthalamic Nucleus

BACKGROUND: Many recent studies based on non-linearity have been performed to quantify the complex behavior of the brain in order to understand the pathophysiology of Parkinson's disease (PD). METHODS: We calculated the Fractal dimension (FD) and Lyapunov exponent (L1), the non-linear biologic signals, by digital EEG using 'CHASIM' program, non-linear times series signal simulator and then compared the UPDRS score with the degree of atrophy in the substantia nigra upon brain MRI and EEG data respectively. All subjects (N=20) showed definite hemiparkinsonism. RESULTS: Upon EEG analysis, a strong positive correlation was noted between FD of the left hemispheric electrodes (FP1,F3,T3,T5) and the UPDRS scores in left-sided symptomatic patients. Additionally, positive correlations were noted between the ipsilateral MRI index ratio in the right and left-sided symptomatic patients and respective UPDRS scores. CONCLUSIONS: These results suggested that thalamocortical drive is reduced in the contralateral hemisphere to parkinsonian symptoms and thalamocortical or corticothalamic glutaminergic projection in the ipsilateral hemisphere is increased in the early stage of Parkinson's disease. Additionally, hemiparkinsonim may primarilly cause anatomic and functional changes in the contralateral hemisphere and a compensatory effect in the ipsilateral hemisphere at the same time. We suggest that disease duration may be a compensating factor and of which require further investigation. We hope that our results will aid the understanding of the specific patterns of dysfunction and treatment effects by non-linear EEG measures and anatomic changes of the substantia nigra through continuous follow up of the patients. (J Korean Neurol Assoc 19(3):232~238, 2001)
Atrophy ; Brain ; Electrodes ; Electroencephalography* ; Fractals ; Hope ; Humans ; Magnetic Resonance Imaging ; Parkinson Disease* ; Substantia Nigra

To clarify neuronal connection of the medial rectus muscle at brain stem, Bartha strain of the psecudorabies virus(PRV-Ba) and cholera toxin-horeserdish peroxidase(CT-HRP) was injected into medial rectus muscle of the rat. About 84 hours after PRV or CT-HRP injection, the brain was removed and processed immunohistochemical stain for PRV-Ba and neurohistochemical stain for CT-HRP using tetramethyl benzidine. The CT-HRP positive reaction was only present in ipsilateral oculomotor nucleus, contralateral abducence nucleus and bilaterally in rostral interstitial nucleus of medial longitudinal fasciculus, olivary pretectal nucleus, medial and superior vestibular nucleus, nucleus prepositus hypoglossi, prerubral field, nucleus Darkschewitsch, lateral substantia nigra, terminal nucleus of accessory nucleus, dorsal raphenucleus, locus ceruleus and pontime reticular formation. This study confirmed that both oculomotor nucleus and abducence nucleus were connected with each other through the medial longitudinal fasciculus, and neuronal connection of the medial rectus muscle in the rat brain stem.
Animals ; Brain Stem* ; Brain* ; Cholera ; Locus Coeruleus ; Neurons ; Rats* ; Reticular Formation ; Substantia Nigra

Although secondary delayed neuronal death has been considered as a therapeutic target to minimize brain damage induced by several injuries, delayed neuronal death does not occur always. In this study, we investigated possible mechanisms that prevent delayed neuronal death in the ATP-injected substantia nigra (SN) and cortex, where delayed neuronal death does not occur. In both the SN and cortex, ATP rapidly induced death of the neurons and astrocytes in the injection core area within 3 h, and the astrocytes in the penumbra region became hypertropic and rapidly surrounded the damaged areas. It was observed that the neurons survived for up to 1-3 months in the area where the astrocytes became hypertropic. The damaged areas of astrocytes gradually reduced at 3 days, 7 days, and 1-3 months. Astrocyte proliferation was detectable at 3-7 days, and vimentin was expressed in astrocytes that surrounded and/or protruded into the damaged sites. The NeuN-positive cells also reappeared in the injury sites where astrocytes reappeared. Taken together, these results suggest that astroycte survival and/or gliosis in the injured brain may be critical for neuronal survival and may prevent delayed neuronal death in the injured brain.
Adenosine Triphosphate ; Astrocytes ; Brain Injuries ; Brain* ; Gliosis ; Neurons* ; Substantia Nigra ; Vimentin

We describe two patients with speech-induced oromandibular dystonia. One patient showed mainly jaw dystonia, while the other patient had lingual dystonia. A brain MRI revealed acute cerebral infarctions in the midbrain near the substantia nigra in the patient with jaw dystonia, while the patient with the lingual dystonia showed no structural lesions. Symptoms in both patients were partly improved with sensory tricks, such as chewing gum or holding a candy in their mouths. Their symptoms were completely recovered with anticholinergic therapy.
Brain ; Candy ; Cerebral Infarction ; Chewing Gum ; Dystonia* ; Humans ; Jaw ; Magnetic Resonance Imaging ; Mesencephalon ; Mouth ; Substantia Nigra

To determine whether toxic and trace elements may play -a role as ail etiologic factor in the development of Parkinson's disease (PD), we measured the levels of toxic and trace elements in the hair from 56 PD patients and 50 normal controls with atomic absorption spectrophotometer In the hair of PD, the zinc concentration showed a significantly lower amount (p=O. 0001) and the concentrations of lead, cad mium, and copper showed a significantly larger amount (Pb, Cd, Cu : p=0.0012, 0. 0444, 0.0286) compared with those of the normal controls. There were no significant differences between the two groups in concentrations of mercury, manganese, iron and aluminum. The levels of each of the toxic and trace elements measured had no significant relationship with Hoehn-Yahr stage, age or the duration of disease. Our data was inconsistent with previous results that analysed the levels of toxic and trace elements in substantia nigra of parkinsonian patients. Due to significant differences in the levels of zinc, copper, lead and cadmium between PD and normal control group, there may be a relationship between PD and those toxic and trace elements. Hair analysis can be so easily applied in clinical practice that a large scale study should be attempted to further evaluate the relationship between trace elements and PD.
Absorption ; Aluminum ; Cadmium ; Copper ; Hair* ; Humans ; Iron ; Manganese ; Parkinson Disease* ; Substantia Nigra ; Trace Elements ; Zinc

BACKGROUND AND PURPOSE: Previous T2 relaxometry studies have provided evidence for regional brain iron deficiency in patients with restless legs syndrome (RLS). Measurement of the iron content in several brain regions, and in particular the substantia nigra (SN), in early- and late-onset RLS patients using T2 relaxometry have yielded inconsistent results. In this study the regional iron content was assessed in patients with early- and late-onset RLS using magnetic resonance imaging (MRI), and compared the results with those in controls. METHODS: Thirty-seven patients with idiopathic RLS (20 with early onset and 17 with late onset) and 40 control subjects were studied using a 3.0-tesla MRI with a gradient-echo sampling of free induction decay and echo pulse sequence. The regions of interest in the brain were measured independently by two trained analysts using software known as medical image processing, analysis, and visualization. The results were compared and a correlation analysis was conducted to investigate which brain areas were related to RLS clinical variables. RESULTS: The iron index in the SN was significantly lower in patients with late-onset RLS than in controls (p=0.034), while in patients with early-onset RLS there was no significant difference. There was no significant correlation between the SN iron index of the late-onset RLS group and clinical variables such as disease severity. CONCLUSIONS: Late-onset RLS is associated with decreased iron content in the SN. This finding supports the hypothesis that regional brain iron deficiency plays a role in the pathophysiology of late-onset RLS.
Brain* ; Humans ; Iron ; Magnetic Resonance Imaging* ; Red Nucleus ; Restless Legs Syndrome* ; Substantia Nigra