• The Korean Journal of Physiology and Pharmacology
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• 제4권4호
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• pp.275-281
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• 2000

Cholecystokinin (CCK) is a gastrointestinal hormone which plays an important role in satiety and gastric motility. It is also widely distributed throughout the central nervous system, where it appears to be involved in the central control of anxiety, feeding behavior and nociception. Two distinct CCK receptor types, $CCK_A$ and $CCK_B,$ have been found in the brain. Both CCK receptors coexist in the rat nucleus tractus solitarius (NTS), which is the primary center for the coordination of peripheral and central activities related to gastrointestinal, cardiovascular and respiratory functions. In order to study ionic actions of CCK on each type of receptor, we investigated the effects of CCK-8S on neurons located in the NTS of the rat using whole-cell patch-clamp recordings in brainstem slices. Application of CCK-8S, under current clamp, produced a membrane depolarization accompanied by action potential firing. This CCK-evoked excitation was dose-dependent $(10\;nM{\sim}10\;{\mu}M)$ and observed in more than 60% of NTS neurons. Under voltage clamp conditions, CCK-8S induced an inward current with a notably increased spontaneous excitatory synaptic activity. However, CCK-8S did not significantly change the amplitude of pharmacologically isolated and evoked EPSP(C)s. Using selective $CCK_A$ and $CCK_B$ receptor antagonists, we observed two different effects of CCK-8S, which suggest $CCK_A$ receptor-mediated inhibitory and $CCK_B$ receptor-mediated excitatory effects in the NTS. These results may help to explain the ability of CCK to modulate gastrointestinal and other reflex systems in the NTS.

• Journal of Audiology & Otology
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• 제25권3호
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• pp.163-170
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• 2021

Cortical deafness is a clinical rarity whereby a patient is unresponsive to all types of sounds despite the preserved integrity of the peripheral hearing organs. In this study, we present a patient who suddenly lost his hearing following ischaemic infarcts in both temporal lobes with no other neurological deficits. The CT confirmed damage to the primary auditory cortex (Heschl's gyrus) of both hemispheres. Initially, the patient was unresponsive to all sounds, however, he regained some of the auditory abilities during 10 months follow up. Pure tone threshold improvement from complete deafness to the level of moderate hearing loss in the right ear and severe in the left was observed in pure tone audiometry. Otoacoustic emissions, auditory brainstem responses, and acoustic reflex findings showed normal results. The middle and late latency potential results confirmed objectively the improvement of the patient's hearing, however, after 10 months still, they were somewhat compromised on both sides. In speech audiometry, there was no comprehension of spoken words neither at 3 nor at 10 months. The absent mismatch negativity confirmed above mentioned comprehension deficit. The extensive auditory electrophysiological testing presented in this study contributes to the understanding of the neural and functional changes in cortical deafness. It presents the evolution of changes after ischaemic cerebrovascular event expressed as auditory evoked potentials starting from short through middle and long latency and ending with event-related potentials and supported by neuroimaging.

• 대한청각학회지
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• 제25권3호
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• pp.163-170
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• 2021

Cortical deafness is a clinical rarity whereby a patient is unresponsive to all types of sounds despite the preserved integrity of the peripheral hearing organs. In this study, we present a patient who suddenly lost his hearing following ischaemic infarcts in both temporal lobes with no other neurological deficits. The CT confirmed damage to the primary auditory cortex (Heschl's gyrus) of both hemispheres. Initially, the patient was unresponsive to all sounds, however, he regained some of the auditory abilities during 10 months follow up. Pure tone threshold improvement from complete deafness to the level of moderate hearing loss in the right ear and severe in the left was observed in pure tone audiometry. Otoacoustic emissions, auditory brainstem responses, and acoustic reflex findings showed normal results. The middle and late latency potential results confirmed objectively the improvement of the patient's hearing, however, after 10 months still, they were somewhat compromised on both sides. In speech audiometry, there was no comprehension of spoken words neither at 3 nor at 10 months. The absent mismatch negativity confirmed above mentioned comprehension deficit. The extensive auditory electrophysiological testing presented in this study contributes to the understanding of the neural and functional changes in cortical deafness. It presents the evolution of changes after ischaemic cerebrovascular event expressed as auditory evoked potentials starting from short through middle and long latency and ending with event-related potentials and supported by neuroimaging.

• Neonatal Medicine
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• 제16권2호
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• pp.213-220
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• 2009

목 적 : 의미 있는 난청은 정상 신생아에서 1,000명당 1-3명의 비율로 발생하는 흔한 질환으로 신생아 중환자실 집중치료를 받은 경우 1,000명당 2-4명의 비율로 발생하는 것으로 보고되고 있고, 난청의 발생률이 높은 신생아 집중치료를 받은 신생아들도 보험혜택의 제한과 추적관찰 실패율이 높은 실정이다. 이에 저자들은 지난 5년간 신생아 집중치료실에서 퇴원한 아기들의 난청 발병률 및 외래추적 관찰률을 확인하고, 신생아중환자실에서의 청각 선별검사의 의의에 대하여 알아보고자 하였다. 방 법 : 2003년 3월부터 2008년 3월까지 울산대학교 의과대학 서울아산병원 신생아 중환자실에서 집중치료를 받은 총 2,137명 중 2,000명을 대상으로 하였다. 신생아 중환자실 퇴원하기 전 신경과에 의뢰되어 뇌간유발 반응검사(AEP)로 1차 선별검사를 시행 후 비정상으로 나올 경우 신생아중환자실내 혹은 이비인후과 및 신생아 외래에서 추적관찰을 하였다. 결 과 : 2,123명 중 67명이 재검판정을 받아 재검률은 3.35%이었고 52명이 2차 청력검사를 시행 받았다. 세 번 이상의 청력검사를 받고 최종적으로 16명(0.8%)이 치료적 중재가 필요하거나 언어치료와 함께 외래 추적관찰이 필요한 비정상군으로 분류되었다. 비정상군의 평균 재태주령은 36주 6일, 평균 출생체중은 2,180 g, 1분 평균 아프가 점수는 각각 1분에 5점, 5분에 7점이었으며, 1차부터 3차까지의 평균 청력 검사 시행일은 각각 17일, 53일, 152일이었다. 전체 16명 중 남아는 6명이었으며 양측성 청력손실 4명, 편측성 청력손실 2명이었고, 여아는 양측성 청력손실 6명, 편측성 청력손실 4명으로 전체 남녀의 비율은 1:1.67 이었다. 경증, 중증도, 중증 난청 환아 수는 각각 3명, 1명, 2명이었고 최중증 난청 환아는 9명으로 이 중 5명은 양측성 4명은 편측성 청력손실이 있었다. 16명중 5명은 대한민국 보험공단에서 제시하는 고위험군에 포함되는 위험요소가 없었다. 결 론 : 본원 신생아중환자실에서 집중치료를 받은 환아의 0.8%에서 인공와우이식이나 언어치료가 필요한 청각이상을 나타내었다. 이는 정상 신생아에서 보고되는 청각이상에 비하여 약 10배 가량 높은 비율로 향후 의료진들의 신생아 난청의 심각성에 대한 의식변화와 제도적인 측면에서 더 많은 뒷받침으로 향상된 예후를 기대하여 본다.