• Journal of Korean Neurosurgical Society
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• v.45 no.4
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• pp.231-235
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• 2009

Objective : While many factors contribute to aging, changes in calcium homeostasis and calcium related neuronal processes are likely to be important. High intracellular calcium is toxic to cells and alterations in calcium homeostasis are associated with changes in calcium-binding proteins, which confine free $Ca^{2+}$. We therefore assayed the expression of the calcium binding proteins calretinin and calbindin in the central auditory nervous system of rats. Methods : Using antibodies to calretinin and calbindin, we assayed their expression in the cochlear nucleus, superior olivary nucleus, inferior colliculus, medial geniculate body and auditory cortex of young (4 months old) and aged (24 months old) rats. Results : Calretinin and calbindin staining intensity in neurons of the cochlear nucleus was significantly higher in aged than in young rats (p<0.05) The number and staining intensity of calretinin-positive neurons in the inferior colliculus, and of calbindin-positive neurons in the superior olivary nucleus were greater in aged than in young rats (p<0.05). Conclusion : These results suggest that auditory processing is altered during aging, which may be due to increased intracellular $Ca^{2+}$ concentration, consequently leading to increased immunoreactivity toward calcium-binding proteins.

• Korean Journal of Veterinary Research
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• v.44 no.3
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• pp.335-341
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• 2004

This study was undertaken to examine the developmental expression of osteopontin(OPN) in the mouse brain. In Western blotting analysis, the expression of OPN was noted initially at embryonic stage and increased gradually after birth and decreased at postnatal day 60(P60). In immunohistochemistry, OPN expression was found in the interstitial nucleus Cajal and the substantia nigra reticularis in anterior part of the brain and in the inferior olivary complex, the parabrachial nucleus, the facial nucleus, the gigantocellular reticular nucleus, the trigeminal nucleus and the anterior interposed nucleus in posterior part of the brain at P31 and P60. In addition, OPN expression in widespread neurons appeared during the period of neuronal differentiation, increased just after birth and decreased with maturation. These results suggest that OPN contributes to developmental processes, including the differentiation and maturation of specific neuronal populations.

• Journal of Acupuncture Research
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• v.17 no.2
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• pp.261-276
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• 2000

본 실험은 pseudorabies 바이러스 (PRV) 의 Bartha strain 을 안면신경의 측두지, 하지를 지배하는 신경 (좌골신경) 및 상지를 지배하는 신경 (요골, 척골, 정중신경) 에 주입한 후 4 일간의 생존시간이 경과한 후 척수와 뇌를 적출하여 동결절편을 제작한 후 면역조직화학적 염색기법과 X-gal 조직화학 염색법을 시행하여 염색된 신경세포체를 척수와 뇌에 투사된 공통영역을 관찰하고 두침의 영역중 하나인 운동구와 사지와의 관계에 대한 실험적 증거를 제시하고자 시행하였다. 위의 실험에서 얻어진 결과는 아래와 같다. 1. 안면신경의 측두지, 하지를 지배하는 신경 (좌골신경) 및 상지를 지배하는 신경 (요골, 측골, 정중신경) 에서 투사된 공통된 영역은 척수에서 경수의 층판 1-IV, 흉수의 intermediolateral nucleus(IML), dorsal nucleus(D) 및 층판 X, 요수의 층판 IV, V, 천수의 층판 IV, V, IX, X 등의 영역에서 관찰되었고, 뇌줄기에서는 caudoventrolateral reticular nucleus(CVL), nucleus solitary tract(Sol), rostroventrolateral nucleus(RVL), area postrema(AP), raphe nuclei(raphe pallidus, raphe obscurus, raphe magnus), inferior olivary nucleus 의 등쪽부분 (gigantocellular reticular nucleus, Gi), Kolliker-Fuse nucleus(KF), central gray(CG), dorsal raphe nucleus (DR) and A5 영역에 표지된다. 또한 paraventricular hypothalamic nucleus(PRV) 와 lateral hypothalamic reticular nucleus(LH)에서도 관찰되고 locus coeruleus(LC) 와 subcoeruleus nuc!eus(SubCA) 에서도 관찰된다.

• 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.

• The Korean Journal of Physiology and Pharmacology
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• v.6 no.4
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• pp.193-197
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• 2002

In spite of abundant anatomical evidences for the fiber connection between vestibular nuclei and inferior olivary (IO) complex, the transmission of vestibular information through the vestibulo- olivo-cerebellar climbing fiber pathway has not been physiologically established. The aims of the present study were to investigate whether there are IO neurons specifically responding to horizontal rotation and also in which subregions of IO complex these vestibularly-activated neurons are located. The extracellular recording was made in 68 IO neurons and responses of 46 vestibularly-activated cells were analyzed. Most of the vestibularly-activated IO neurons responded to signals of vertical rotation (roll), while a small number (13/46) of recorded cells were activated by horizontal canal signal (yaw). Regardless of yaw-sensitive or roll-sensitive, vestibular IO neurons were excited, when the animal was rotated to the side contralateral to the recording side. The gain and excitation phase were very similar to otolithic or vertical-canal responses. Histologic identification of recording sites showed that most of vestibular IO neurons were located in ${\beta}$ subnucleus. Electrical stimulation of a HSC evoked an inhibitory effect on the excitability of the ipsilateral IO neurons. These results suggest that IO neurons mainly in the ${\beta}$ subnucleus receive vestibular signals from semicircular canals and otolithic organs, encode them, and transmit vestibular information to the cerebellum.

• Journal of Biomedical Engineering Research
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• v.32 no.1
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• pp.55-60
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• 2011

Although sound intensity is considered as one of important factors in auditory processing, its neural mechanism in auditory neurons with limited dynamic range of firing rates is still unclear. In this study, we examined the effect of sound intensity adaptation on the change of glucose metabolism in a rat brain using [F-18] micro positron emission tomography (PET) neuroimaging technique. In the experiment, broadband white noise sound was given for 30 minutes after the [F-18]FDG injection in order to explore the functional adaptation of rat brain into the sound intensity levels. Nine rats were scanned with four different sound intensity levels: 40 dB, 60 dB, 80 dB, 100 dB sound pressure level (SPL) for four weeks. When glucose uptake during the adaptation of a high intensity sound level (100 dB SPL) was compared with that during adaptation to a low intensity level (40 dB SPL) in the experiment, the former induced a greater uptake at bilateral cochlear nucleus, superior olivary complexes and inferior colliculi in the auditory pathway. Expectedly, the metabolic activity in those areas linearly increased as the sound intensity level increased. In contrast, significant decrease interestingly occurred in the bilateral auditory cortices: The activities of auditory cortex proportionally decreased with higher sound intensities. It may reflect that the auditory cortex actively down-regulates neural activities when the sound gets louder.

• Applied Microscopy
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• v.40 no.2
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• pp.53-64
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• 2010

Glutamate receptors may play a critical role in the refinement of developing synapses. The lateral superior olivary nucleus (LSO)-medial nucleus of trapezoid body (MNTB) synaptic transmission in the mammalian auditory brain stem mediate many excitatory transmitters such as glutamate, which is a useful model to study excitatory synaptic development. Hearing deficits are often accompanied by changes in the synaptic organization such as excitatory or inhibitory circuits as well as anatomical changes. Owing to this, circling mouse whose cochlea degenerates spontaneously after birth, is an excellent animal model to study deafness pathophysiology. However, little is known about the development regulation of the subunits composing these receptors in circling mouse. Thus, we used immunohistochemical method to compare the N-Methyl-D-aspartate receptor (NMDA receptor) NR1, NR2A, NR2B distribution in the LSO which project glutamergic excitatory input into the auditory brainstem, in circling mouse of postnatal (p) 7 and 16, which have spontaneous mutation in the inner ear, with wild-type mouse. The relative NMDAR1 immunoreactive density of the LSO in circling mouse p7 was $128.67\pm8.87$ in wild-type, $111.06\pm8.04$ in heterozygote, and $108.09\pm5.94$ in homozygote. The density of p16 circling mouse was $43.83\pm10.49$ in wild-type, $40\pm13.88$ in heterozygote, and $55.96\pm17.35$ in homozygote. The relative NMDAR2A immunoreactive density of LSO in circling mouse p7 was $97.97\pm9.71$ in wild-type, $102.87\pm9.30$ in heterozygote, and $106.85\pm5.79$ in homozygote. The density of LSO in p16 circling was $47.4\pm20.6$ in wild-type, $43.9\pm17.5$ in heterozygote, and $49.2\pm20.1$ in homozygote. The relative NMDAR2B immunoreactive density of LSO in circling mouse p7 was $109.04\pm6.77$ in wild-type, $106.43\pm10.24$ in heterozygote, and $105.98\pm4.10$ in homozygote. the density of LSO in p16 circling mouse was $101.47\pm11.5$ in wild-type, $91.47\pm14.81$ in heterozygote, and $93.93\pm15.71$ in homozygote. These results reveal alteration of NMDAR immunoreactivity in LSO of p7 and p16 circling mouse. The results of the present study are likely to be relevant to understand the central change underlying human hereditary deafness.