• Communications of the Korean Institute of Information Scientists and Engineers
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• v.5 no.1
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• pp.62-78
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• 1987

인체의 신경조직에서 정보를 전달하기 위해서 발생하는 Signal인 spontaneous firing의 origin을 조사하기 위해서 Hodgkin-Huxley의 수학적 모델을 기초로 하여 Simulation을 하였다. 그 모델의 Parameter인 Stimulus current를 zero로 함으로써 생리학적으로는 stimulus없이 어떤 특정한 근육근 등에서 발생되는 spontaneous firing의 경우가 되었고 또한 physical meaning들을 포함하고 있는 parameter들의 상호 독립적 상태를 초래하여 그 firing의 origin을 연구할수 있게 되었다. 이 simulation을 통하여 얻어진 수확들은 origin에 대한 조사 연구뿐만 아니라 많은 새로운 사실의 발견에도 존재한다. 그 예로서는 이 simulation이 stimulus 없이 spontaneous firing을 얻은 최초가 되며 이 분야에 명성있는 학자들이 simulation을 통해서는 매우 제한된 수의 firing만을 얻을수 있다고 단언했으나 그 반증이 여기에서 입증되었고 leakage conductance의 중요성을 예측하게 한다. 특히 leakage potential이 firing의 수를 조정할수 있다는 것은 특이한 발견이다.

• The Korean Journal of Zoology
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• v.35 no.2
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• pp.194-202
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• 1992

This study has been performed to investigate normal synaptic organizations in the subesophageal ganglion and terminaiion of antennal receptor cells in the ipsilateral subesophageal gan91ion of Pieris rapae. The various normal synaptic organizations in subesophageal ganglion could be differentiated into the five types. The proximal removal of a left antenna resulted in the weakly-dark, semidark and dark degenerations in the type I bostons of the ipsilateral subesophageal ganglion. Therefore, it was concluded that the axon terminals of the receptor cells projecting from the antenna into the brain form the type 1 synapses together with the dendrites in the ipsilateral subesophageal ganglion.

• The Korean Journal of Zoology
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• v.33 no.1
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• pp.28-34
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• 1990

The ipsilateral dorsal lobe of the brain one or two days after cutting a left antenna in Pieris rapae has been examined with electron microscope to investigate the connection of the receptor cells between antenna and dorsal lobe. The proximal removal of the left antenna leads to the weakly-dark, semidark or dark degeneration of antennal receptor tenninals in ipsilateral dorsal lobe. Therefore, it is concluded that some of antennal receptor cells which project into the brain terminate in ipsilateral dorsal lobe located immediately behind the antennal lobe.

• Journal of Veterinary Clinics
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• v.17 no.2
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• pp.470-474
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• 2000

A Shih Tzu Puppy had clinical onset of anotexia crying and progression of neurological sings when enlargement of the cranial vault at 1 month old and died after showing clinical signs during 2 months period. Radiological and pathological examinations were performed. Radiological findings were homogeneous appearance of the calvaria with cortical thinning, loss of the normal convolutional skull markings and persistent fontanelles. Grossly enlargement of the cranial vault thinning of the bone and defective closure of the fontanelles were also observed. The entire subcortical area of the cerebral hemispheres with severe, dilatation of ventricles and cerebrospinal fluid(CSF) wits absent. There was parenchyma atrophy affecting chiefly in the white mater and the cerebral cortices, axon degeneration and necrosis and gitter cell infiltration in the whiter matter and the subependymal area. Mononuclear perivacular cuffing in the cerebrum and the pons was shown. Based on the radiological, gross and histopathological findings, this case was believed to have congenital hydrocephalus with nonsuppurative encephahitis. Possible etiology on the case is also discussed.

• Proceedings of the Korean Biophysical Society Conference
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• 2003.06a
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• pp.36-36
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• 2003

Goldfish retina has been well studied to a great extent. In spite of that, electrical characteristics of dissociated horizontal cells(HCs) have not been identified in detail. Thus the cone-and the rod- HCs dissociated from goldfish retina were investigated electrophysiologically using whole-cell patch-clamping recording. To explore the basic electrical property, We examined voltage-dependent channels in all types of HCs. For the futher understanding of GABAergic pathway, the localization and distribution of GABA receptors was examined in cone- HCs including HC axon terminals(ATs).

• Biomedical Science Letters
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• v.26 no.1
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• pp.1-7
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• 2020

Alzheimer's disease (AD) is the most common neurodegenerative disorder and is expected to become more and more widespread as life expectancy increases. New therapeutic target, as well as the identification of mechanisms responsible for pathology, is urgently needed. Recently, microglial actin cytoskeleton has been proposed as a beneficial role in axon regeneration of brain injury. This review highlights in understanding of the characteristics of microglial actin cytoskeleton and discuss the role of specific actin-interacting proteins and receptors in AD. The precise mechanisms and functional aspects of motility by microglia require further study, and the regulation of microglial actin cytoskeleton might be a potential therapeutic strategy for neurological diseases.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.31A no.8
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• pp.62-71
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• 1994

A novel semiconductor device is proposed to be used as a processing element for the implementation of pulse-mode neural networks which consists of alternating n' GaAs quantum wells and undoped AlGaAs barriers sandwitched between n' GaAs cathode and P' GaAs anode and in simple circuit in conjunction with a parallel capacitive and resistive load the trigger circuit generates neuron-like pulse train output mimicking the function of axon hillock of biological neuron. It showed the sigmoidal relationship between the frequency of the pulse-train and the applied input DC voltage. In conjunction with MQWIMD the various neural circuits are proposed especially a neural chip monolithically integrated with photodetectors in order to perfrom the pattern recognition.

• Annals of Clinical Neurophysiology
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• v.21 no.1
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• pp.1-6
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• 2019

Anhidrosis refers to the condition in which the body does not respond appropriately to thermal stimuli by sweating. Sweating plays an important role in maintaining the body temperature, and its absence should not be overlooked since an elevated body temperature can cause various symptoms, even leading to death when uncontrolled. The various neurological disorders that can induce anhidrosis make a detailed neurological evaluation essential. The medication history of the patient should also be checked because anhidrosis can be caused by various drugs. The tests available for evaluating sweating include the quantitative sudomotor axon reflex sweat test, thermoregulatory sweat test, sympathetic skin response, and electrochemical skin conductance. Pathological findings can also be checked directly in a skin biopsy. This review discusses the differential diagnosis and evaluation of anhidrosis.

• Applied Microscopy
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• v.35 no.3
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• pp.135-152
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• 2005

Prefrontal cortex is a psychological and metaphysical cortex, which deals with feeling, memory, planning, attention, personality, etc. And it also integrates above-mentioned events with motor control and locomotor activities. Prefrontal cortex works as a highest CNS center, since the above mentioned functions are very important for one's successful life, and further more they are upgraded every moments through memory and learning. Many of these highest functions are supposed to be generated via forebrain basal nuclei (caudate nucleus, fundus striati nucleus, accumbens septi nucleus, septal nucleus, etc.). In this experiment, prefrontal efferent terminals within basal forebrain nuclei were ultrastructurally studied. Spraque Dawley rats, weighing $250{\sim}300g$ each, were anesthetized and their heads were fixed on the stereotaxic apparatus (experimental model, David Kopf Co.). Rats were incised their scalp, perforated a 3mm-wide hole on the right side of skull at the 11mm anterior point from the frontal O point (Ref. 13, Fig. 1), suctioned out the prefrontal cortex including cortex of the frontal pole, with suction instrument. Two days following the operations, small tissue blocks of basal forebrain nuclei were punched out, fixed in 1% glutaraldehyde-1% paraformaldehyde solution followed by 2% osmium tetroxide solutions. Ultrathin sections were stained with 1% borax-toluidin blue solution, and the stained sections were obserbed with an electron microscope. Degenerating axon terminals were found within all the basal forbrain nuclei. Numbers of degenerated terminals were largest in the caudate nucleus, next in order, in the fundus striati nucleus, in the accumbens septi nucleus, and the least in the septal nucleus. Only axospinous terminals were degenerated within the caudate nucleus and the fundus striati nucleus, and they showed the characters of striatal motor control system. Axodendritic and axospinous terminals were degenerated within the accumbens septi nucleus and the lateral septal nucleus, and they showed the characters of visceral limbic system. Prefrontal role in integrating the limbic system with the striatal system, en route basal forebrain nuclei, was discussed.

• The Korean Journal of Pain
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• v.13 no.2
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• pp.149-155
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• 2000

Background: Pulsed radiofrequency (RF) lesioning is a painless procedure and causes no neurodestruction and neuritis-like reaction are common following conventional RF lesioning. There is little data about the effect of pulsed RF especially with regard to its suitability for the treatment of acute pain. The possibility of a placebo effect cannot be ruled out because a double-blind study was not performed in previous studies. There is also no neuropathologic study about pulsed RF. Methods: The rats were anesthetized with sodium pentobarbital (40 mg/kg, i.p.; supplemented as necessary). The common sciatic nerve was exposed by blunt dissection through biceps femoris. Pulsed RF was administered to the common sciatic nerve using a 30 ms/s pulse with for 120 seconds. The temperature reached was no more than $42^{\circ}C$. Analgesia was determined using hot-plate assay shortly and, 3 days and 1 week before, and 2 weeks after operation. Lesions were examined with LM (light microscope) and EM (electron microscope) 2 weeks later. Results: There were no differences in response latencies between the control and experimental group. There were many vacuoles with hyaline bodies in the Schwann cell cytoplasm rather than axon in LM and larger electron dense bodies. No changes were found in the axon or unmyelinated fibers. Only small changes were found in the sheaths of myelinated fibers and Schwann cells. Conclusions: We therefore do think that any analgesic effect of pulsed RF is not a result of block of neural conduction. But rather than it can be attributed to others factors. It was also ineffective as a treatment for acute pain such as that caused by the hot-plate test.