• Korean Journal of Veterinary Research
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• v.37 no.3
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• pp.489-497
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• 1997

The distributions characteristics of neurons displaying immunoreactivity to the catecholamine synthetic enzymes, tyrosine hydroxylase(TH), dopamine-${\beta}$-hydroxylase(DBH), and phenylethanolamine-N-methyltransferase(PNMT) were examined in the adjacent sections of the substantia nigra & ventral tegmentum of the Striped Field Mouse(Apodemus agrarius coreae). None of these cell groups displayed either DBH or PNMT immunoreactivity. Many TH-immunoreactive neurons were present in the substantia nigra & ventral tegmentum. The major dopaminergic cell(TH-positive, DBH- & PNMT-negative) group in the midbrain was present in the pars compacta of substantia nigra and adjacent ventral tegmentum. And smaller dopaminergic cell groups Were found in the pars reticulata of the substantia nigra and central liner nucleus.

• Sleep Medicine and Psychophysiology
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• v.2 no.2
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• pp.133-137
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• 1995

The author reviews current knowledge about what REM sleep is and where and how it is generated. REM sleep is the state in which our most vivid dreams occur. REM sleep is identified by the simultaneous presence of a desynchronized cortical EEG, an absence of activity in the antigravity muscles(atonia), and periodic bursts of rapid eye movements. Another characteristic phenomena of REM sleep are the highly synchronized hippocampal EEG of theta frequency and the ponto-geniculo-occipital(PGO) spike. All these phenomena can be explained in terms of changes in neuronal activity. Transection studies have determined that the pons is sufficient for generating REM sleep. Lesion studies have identified a small region in the lateral pontine tegmentum corresponding to lateral portions of the nucleus reticularis pontis oralis(RPO) and the region immediately ventral to the locus coeruleus, which is required for REM sleep. Unit recording studies have found a population of cells within this region that is selectively active in REM sleep. Cholinergic neurons of the giant cell field of pontine tegmentum(ETG), which is 'REM a sleep-on cells', has shown to be critically involved in the generation of REM sleep. Noradrenergic neurons of the locus coeruleus and serotonergic neurons of the dorsal raphe, which are called 'REM sleep-off cells', appear to act in a reciprocal manner to the cholinergic neurons. It is proposed that the periodic cessations of discharge of 'REM sleep-off cells' during REM sleep might be significant for the prevention of the desensitization of receptors of these neurons.

• Animal Systematics, Evolution and Diversity
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• v.38 no.1
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• pp.14-19
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• 2022

Leptochiton Gray, 1847 is one of the most ancient chiton groups which includes more than 130 species that occur in cold and deep waters worldwide. Due to their small-sized body, they are often confused as juveniles of other chiton species. Moreover, lack of morphological information makes species identification of this group very challenging. To date, only two Leptochiton species(L. fuliginatus and L. rugatus) have been reported from Korean waters. In this study, we found L. hakodatensis(Thiele, 1909) for the first time in Korea and described microscopic morphological characters of valves (tegmentum sculpture), girdle scale, and radula using a scanning electron microscopy (SEM). Leptochiton hakodatensis is morphologically similar to L. fuliginatus and L. rugatus, but differently characterized by having dorso-ventrally rounded (not carinated) intermediate valves, girdle (perinotum) scales sculptured with 4-7 longitudinal ribs, and bicuspid major lateral teeth of radula. In addition to morphological examination, we determined the partial mitochondrial cytochrome c oxidase subunit I(cox1) as a DNA barcode sequence information. This is the first report that describes microscopic characters (tegmentum of valves, girdle structure, and radula) of L. hakodatensis using a SEM. This study provides a morphological basis for describing Leptochiton species and discovery of a "hidden" species of this genus.

• The Journal of Internal Korean Medicine
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• v.21 no.5
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• pp.889-895
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• 2000

I experienced a case of a patient with clinical features of cerebellar dysfunction in the intracranial hemorrhage which encroached the basis of lower pontine and all parts of pontine tegmentum. So I report this case with bibliographical inquiry. In addition, I applied the treatment of Oriental medicine to sequelae of intracranial hemorrhage like disorders of eye movement, central dizziness, cerebellar tremor and ataxias but the effect did not meet my expectation. I anticipate more clinical studies and reports on this hereafter.

• Journal of Korean Neurosurgical Society
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• v.60 no.3
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• pp.375-379
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• 2017

Midbrain gliomas are relatively rare neoplasms with a generally benign prognosis, with dissemination or metastasis not previously reported. We describe here a woman, in whom magnetic resonance imaging scans showed hydrocephalus and a tegmental lesion in the upper aqueduct. Endoscopic third ventriculostomy and biopsy were performed; during surgery, a second small lesion was observed in the infundibular recess. Histologically, the two lesions had the characteristics of low grade astrocytoma, suggesting that the midbrain astrocytoma may have been disseminated via the cerebral spinal fluid to the infundibular recess. Postoperatively this patient received radiotherapy for nearly one month. Although patients with these tumors are not usually administered adjunctive therapy, radiation and, combined modality therapy, including surgery, radiotherapy, and chemotherapy, may be beneficial in patients with midbrain gliomas with dissemination.

• Journal of Photoscience
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• v.9 no.2
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• pp.21-24
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• 2002

Pineal organs of poikilotherm vertebrates transform the environmental light information into a humoral message and a neuronal activity. The former is melatonin, and the latter is modulation of the impulse in ganglion cells. The ganglion cells are physiologically classified into luminosity (achromatic) type and chromatic one, as the neural activity is modulated in two ways. We attempted to classify the pineal ganglion cells with morphological characteristics by means of the three- dimensional reconstruction method. In the pineal ganglion cells of river lamprey, there are two different features, oval and spherical. For comparison of their projection region in the brain, the tracing investigation was also carried out. The application of the neural tracer near mesencephalic tegmentum showed that only oval-shaped ganglion cells were labeled in the pineal organ. These results suggest that the oval-shaped ganglion cell is functionally different from the spherical one.

• Journal of Korean Neurosurgical Society
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• v.29 no.10
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• pp.1360-1364
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• 2000

This 26-year-old man gradually developed a disabling midbrain tremor involving both distal and proximal part of left upper arm. On neurologic examination, oculomotor palsy, and ataxia of the left arm were noted. Radiologic examination revealed a mass lesion on midbrain tegmentum. He was tentatively diagnosed as brain tumor (presumably germinoma) without stereotactic biopsy. Conventional radiation therapy was given for this lesion. Although there was improvement in the radiologic imaging, his midbrain tremor worsened and became untolerable. The authors performed MR-guided stereotactic Vim-thalamotomy. With macroelectrode stimulation and radiofequency lesioning, his resting, postural and action tremors were almost completely abolished in both distal and proximal part of left upper extremity. Authors consider that Vim thalamotomy is still an effective means of controlling midbrain tremor involving proximal upper limb.

• The Journal of Internal Korean Medicine
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• v.25 no.4
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• pp.200-206
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• 2004

Anterior inferior cerebellar artery(AICA) is a branch of the basilar artery which supplies the bloods for ventrolateral cerebellum and the lateral tegmentum of the lower two-thirds of pons. AICA occlusion can cause such symptoms as acute-onset unilateral deafness, vertigo, facial weakness and ataxia. A case of sudden hearing loss, facial palsy and vertigo caused by AICA territory infarction recently presented itself. Korean Oriental and Western medical therapy were applied in combination. Facial palsy and vertigo improved, but hearing loss did not improve. This case is reported with a brief overview of related literatures.

• Annals of Clinical Neurophysiology
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• v.7 no.2
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• pp.80-82
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• 2005

Background: Idiopathic Parkinson's disease (IPD) is closely related to Lewy body pathology. Pathological changes in medullar oblongata and pontine tegmentum have been reported in patients with subclinical motor symptom. Vestibular evoked myogenic potential (VEMP) is mediated by vestibular nuclei in lower brainstem and reflects the function of lower brainstem. The purpose of our study is to estimate the lower brainstem function in IPD patients. Methods: Ten patients with idiopathic Parkinson's disease underwent VEMP test. The patients were divided into Hohn-Yahr (H-Y) stage I (unilateral motor involvement) group and H-Y stage II or more severe (bilateral motor involvement) group. VEMP results were compared between groups using Mann-Whitney U test. Results: Among patients, 6 patients showed abnormal VEMP (unilateral abnormality 2, bilateral abnormalities 4). Between H-Y stage I group and H-Y II,III group, there was no statistical difference in the results of VEMP. Conclusions: We concluded that the lower brainstem dysfunction reflected in VEMP could occur in IPD regardless of the progression of the disease.

• Annals of Clinical Neurophysiology
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• v.3 no.2
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• pp.168-171
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• 2001

It has been said that variable anatomical structures and neural circuits are related to the generation of tremor. There are cerebral cortex, thalamus, basal ganglia, inferior olivary nucleus, midbrain tegmentum, stretch reflex, and musculoskeletal structures. The stretch reflex is related with the physiologic tremor and various peripherally originated tremors. We experienced a case with the post-stroke resting tremor which was induced and aggravated by mechanical stretching stimulation. In the present case, stretch reflex has a major role in the generation and exacerbation of tremor. It is presumed that the development of tremor is attributed to the increased rhythmicity of ventral intermedius nucleus of thalamus. The enhancement of thalamic rhythmicity may be due to the increasement of long latency reflex by post-stroke rigidity. This case suggests that stretch reflex may have a major role in the pathophysiologic mechanisms of a certain centrally originated tremor.