• ALGAE
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• 제34권3호
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• pp.187-198
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• 2019

The exploration of seaweed diversity in poorly studied habitats has often led to the discovery of new species. Sand-covered rocks are an example, as they received less attention than sand-free rocky intertidal habitats during seaweed diversity surveys in Brazil. In sand-covered rocks from Espirito Santo and Rio de Janeiro we found an alga whose morphology was unique among rhodomelacean species previously reported in Brazil. With the aim to clarify the taxonomic identity of this species we studied its morphology, as well as its phylogenetic relationships. Molecular analyses resolved this species in the genus Alsidium (tribe Alsidieae) and differed from sequenced congeners with divergences ${\geq}2.5$ and 4.2% in the rbcL and cox1 genes, respectively. Morphological characters were in agreement with the genus Alsidium, and differed from other species currently recognized in the genus. The species consisted of a basal crust and scarcely branched erect axes with seven pericentral cells covered by a continuous layer of cortical cells. Reproductive structures were formed on clusters of short determinate branches. Therefore, the new species A. oliveiranum is proposed based on morphological and molecular evidence. Our findings contribute to better understand the diversity of the tribe Alsidieae, which is particularly diverse in the Americas.

• Journal of Korean Neurosurgical Society
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• 제66권2호
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• pp.121-132
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• 2023

Objective : The parafascicular nucleus (PF) plays important roles in controlling the basal ganglia. It is not well known whether the PF affects the development of abnormal involuntary movements (AIMs). This study was aimed to find a role of the PF in development of AIMs using optogenetic methods in an animal model. Methods : Fourteen rats were underwent stereotactic operation, in which they were injected with an adeno-associated virus with channelrhodopsin (AAV2-hSyn-ChR2-mCherry) to the lateral one third of the PF. Behavior test was performed with and without optical stimulation 14 days after the injection of the virus. AIM of rat was examined using AIM score. After the behavior test, rat's brain was carefully extracted and the section was examined using a fluorescence microscope to confirm transfection of the PF. Results : Of the 14 rats, seven rats displayed evident involuntary abnormal movements. AIM scores were increased significantly after the stimulation compared to those at baseline. In rats with AIMs, mCherry expression was prominent in the PF, while the rats without AIM lacked with the mCherry expression. Conclusion : AIMs could be reversibly induced by stimulating the PF through an optogenetic method.

• Investigative Magnetic Resonance Imaging
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• 제20권4호
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• pp.250-253
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• 2016

Acute Japanese encephalitis (JE) is an endemic viral infectious disease in various parts of Far East and Southeast Asian countries including Korea. Bilateral thalami are the most common involving sites in JE. Other areas including the basal ganglia, substantia nigra, red nucleus, pons, cerebral cortex and cerebellum may be also involved. We report an extremely unusual brain diffusion-weighted MR imaging (DWI) findings in a 53-year-old man with serologically proven JE involving unilateral deep gray matter and temporal lobe, which shows multifocal high signal intensities in left thalamus, left substantia nigra, left caudate nucleus and left medial temporal cortex on T2-weighted image and DWI with iso-intensity on apparent diffusion coefficient (ADC) map.

• 한국수산과학회지
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• 제33권2호
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• pp.148-152
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• 2000

베도라치의 피부는 크게 상피층과 진피층으로 구분된다. 상피층은 지지세포와 선세포들로 구성된다. 지지세포는 표면세포, 중간세포 및 기저세포로 구분되며, 선세포는 점액분비세포와 곤봉랑 세포로 구분된다. 지지세포들의 세포질은 피질부와 수질부로 나누어지는데, 수질부에는 세포소기관의 발달이 현저하며, 피질부에는 미세섬유의 발달이 뚜렷하다. 표면세포는 입방형이며 핵은 말굽형이다. 중간세포는 불규칙한 형태의 핵을 가지며, 핵과 세포질의 전자밀도는 지지세포 가운데 가장 높다. 기저세포는 원주형이나 핵은 세포질의 위쪽에 위치한다. 점액분비세포의 세포질은 타원형의 분비과립이 대부분을 차지하며, AB-PAS에 적색으로 반응하였다. 조면소포체와 골지체가 발달되어 있다. 곤봉상 세포의 세포질 상부에는 원형의 분비성 물질들이 차지하며, 핵은 장방형이고, 세포질에서는 조면소포체와 활면소포체가 발달되어 있다. 색소세포는 세포질에 전자밀도가 높은 색소과립들을 함유한 종류와 반사소판을 함유한 종류로 구분된다. 섬유세포의 세포질은 아주 잘 발달된 조면소포체들이 대부분을 차지한다.

• Journal of Nutrition and Health
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• 제32권8호
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• pp.864-869
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• 1999

To investigate the effect of dietary phosphatidylcholine(PPC) supplement on memory improvement, biochemical study on the brain, and morphometric studies on the cholinergic neurons in the rat basal forebrain were undertaken. The pregnancy rats were divided into the normal control, the choline deficient and the PPC supplemental groups according to quantity of the PPC in diet. According to choline deficiency and PPC supplement after birth, the neonate rate of the normal control group were subdivided into the control diet(N-N) and the PPC supplied (N-S) groups, the choline deficient group were subdivided into the continually deficient (D-D), the control diet(D-N) and the PPC supplied groups(D-S), and the PPC supplemental group were subdivided into the control diet (S-N)and the continually supplied (S-S)group. The PPC supplemented diet was added 2% egg PPC in AIN 76 formula diet. PPC concentrations and cholinesterase(CE) activities were measured in the serum, the liver and the brain, respectively. Immunohistochemical stains for choline acetyltransferase(ChAT) was employed for the morphological and morphometric studies. The maze test was undertaken to evaluate memory improvement. PPC concentration and CE activities in the serum, liver and the brain were high in the PPC supplemental groups and low in the choline deficient groups. ChAT immunoreactivity neurons at the medial septal diagonal bond complex and the basal forebrain nucleus of Meynert were reduced in the choline deficient groups. Average failure rate for the maze test was the lowest in the S-S group and the highest in the D-D group. Insufficient choline suppley during the neuronal development would result in cholinergic neuronal damage, which could be prevented by adequate PPC supplement. It is consequently suggested that PPC supplement may be effective on memory improvement by maintaining the cholinergic neuronal activity in the basal forebrain of the rats.

• 한국패류학회지
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• 제30권3호
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• pp.211-218
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• 2014

Spermatid differentiations during spermiogenesis and sperm ultrastructures in male Mercenaria stimpsoni were investigated by transmission electron microscopic observations. In the early stage of the spermatid during spermiogenesis, a few granules and a proacrosomal granule, which is formed by the Golgi complex, become a proacrosomal vesicle. Consequently, it becomes an acrosome by way of the process of acrosome formation. The morphologies of the sperm nucleus type and the acrosome of this species have a curved cylindrical type and cap shape, respectively. The spermatozoon is approximately $48-51{\mu}m$ in length including a curved cylinderical sperm nucleus (about $4.18{\mu}m$ long), an acrosome (about $0.52{\mu}m$ in length) and tail flagellum ($42-45{\mu}m$ long). As some ultrastructural characteristics of the acrosomal vesicle, the peripheral parts of two basal rings show electron opaque part (region), while the apex part of the acrosome shows electron lucent part (region). These charateristics of the sperm belong to the family Veneridae in the subclass Heterodonta, unlike a characteristic of the subclass Pteriomorphia showing all part of the acrosome being composed of electron opaque part (region). Therefore, it is easy to distinguish the families or the subclasses by the acrosome structures. Exceptionally, In particular, a cylinder-like nucleus of the sperm is curved (the angle of the nucleus is about $80^{\circ}$), as seen in some species of Veneridae (range from $0^{\circ}$ to $80^{\circ}$). The number of mitochondria in the midpiece of the sperm of this species are four, as one of common characteristics appeared in most species except for a few species in Veneridae in the subclass Heterodonta. Cross-sectioned axoneme of the sperm tail flagellum shows a 9+2 structure.

• 한국가금학회지
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• 제28권3호
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• pp.267-274
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• 2001

부화후 성장하는 꿩 송과샘의 미세구조적 발달을 구명하고자 1일령, 1, 2 및 6개월령을 희생시켜 광학 및 전자현미경을 이용하여 다음과 같은 결과를 얻었다. 광학현미경적 관찰에서 꿩 송과샘의 실질은 피막에 의해 싸여 있고 여기에서 기시하는 결합조직에 의해 불완전한 소엽 (lobule)으로 구분되었다. 송과샘실질은 소엽상과 불완전한 여포살이었으며, 둥근 핵과 염색성이 옅은 송과샘세포와 약간 짙고 길쭉한 핵을 갖는 지주세포로 구성되어 있었다. 전자현미경적 관찰에서 송과샘실질에는 길쭉한 송과샘세포와 지주세포가 소엽의 중심부를 향해 배열되어 있었고 광학현미경에서 소엽의 중심부에는 매우 불규칙한 막성층판복합체이나 포상구조물이 출현하였다. 실질은 비교적 밝은 솔과 샘세포와 짙은 핵을 갖는 지주세포로 구성되어 있었다. 송과샘세포는 잔유성 광수용세포의 형태를 취하였는데, 그 첨단부위의 밝고 팽대된 세포질에는 세포소기관이 빈약하나 섬모, 약간의 유리리보솜과 사립체가 출현하였다. 첨단부위세포질과 핵위부위세포질 사이의 좁아진 경부는 지주세포와 연접복합체를 이루고 목부위세포질내에는 미세소관이 풍부하였다. 핵주위세포질은 풍부하고 다수의 사립체, 잘 발달된 골지장치, 풍부한 과립형질내세망 및 유리 리보솜 등을 함유하고 있었다. 또한 핵아래부위세포질에서 여포의 기저부위로 기저돌기를 내고 있었다. 송과샘세포의 핵아래부위 세포질 및 기저돌기에서 60∼90nm 크기의 치밀소포가 관찰된 것이 특이하였고 짙은 핵을 갖고 긴 독기를 갖는 것이 특징이었다. 이상의 결과는 꿩 송과샘세포가 광수용능은 것의 없고 분비기능을 주로 수행하는 소견이었으며, 성숙 꿩의 송과샘의 미세구조적 연구를 확인하여 번식기와 비번식기에 따른 비교연구가 수행되어야 할 것으로 사료된다.

• Biomolecules & Therapeutics
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• 제28권3호
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• pp.230-239
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• 2020

Previous studies have shown disrupted synaptic plasticity and neural activity in depression. Such alteration is strongly associated with disrupted synaptic structures. Chronic stress has been known to induce changes in dendritic structure in the basolateral amygdala (BLA) and medial prefrontal cortex (mPFC), but antidepressant effect on structure of these brain areas has been unclear. Here, the effects of imipramine on dendritic spine density and morphology in BLA and mPFC subregions of stressed mice were examined. Chronic restraint stress caused depressive-like behaviors such as enhanced social avoidance and despair level coincident with differential changes in dendritic spine structure. Chronic stress enhanced dendritic spine density in the lateral nucleus of BLA with no significant change in the basal nucleus of BLA, and altered the proportion of stubby or mushroom spines in both subregions. Conversely, in the apical and basal mPFC, chronic stress caused a significant reduction in spine density. The proportion of stubby or mushroom spines in these subregions overall reduced while the proportion of thin spines increased after repeated stress. Interestingly, most of these structural alterations by chronic stress were reversed by imipramine. In addition, structural changes caused by stress and blocking the changes by imipramine were corelated well with altered activation and expression of synaptic plasticity-promoting molecules such as phospho-CREB, phospho-CAMKII, and PSD-95. Collectively, our data suggest that imipramine modulates stress-induced changes in synaptic structure and synaptic plasticity-promoting molecules in a coordinated manner although structural and molecular alterations induced by stress are distinct in the BLA and mPFC.

• The Korean Journal of Physiology
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• 제23권1호
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• pp.119-127
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• 1989

This study was undertaken to investigate the effect of medial amygdala on the gastric acid secretion and plasma gastrin concentration in the rats with chronic gastric fistula. After the medial nucleus of amygdala was damaged bilaterally by radiofrequency a. c. through stereotaxically inserted electrodes, the gastric juice was collected in the basal and histamine-stimulated states for 1 hour. The gastric juice was also collected while the medial nucleus of amygdala was stimulated with biphasic square wave in the both states. After the collection of the gastric juice, blood samples were drawn from the abdominal aorta for the radioimmunoassay of plasma gastrin. The results were as follows: 1) The damage of the medial amygdala significantly decreased the gastric juice volume and the acid output in the histamine-stimulated state. 2) The electrical stimulation of the medial amygdala significantly increased the gastric juice volume and the acid output in the histamine-stimulated state, and the acid output in the basal state. 3) The damage of the medial amygdala significantly decreased the plasma gastrin concentration but the electrical stimulation of the medial amygdala did not affect the plasma gastrin concentration. It is therefore suggested that the medial amygdala has a facilitatory influence on the histamine-stimulated gastric acid secretion in rats, and the influence may not be attributed to gastrin release.

• Applied Microscopy
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• 제41권1호
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• pp.31-35
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• 2011

본 연구는 물윗수염박쥐(Myotis daubentonii ussuriensisi)의 정자 미세구조적 특징을 알아보기 위하여 투과전자현미경(TEM)으로 관찰한 결과는 다음과 같다. 물윗수염박쥐 정자두부의 길이는 $4.5{\mu}m$, 폭은 $2.0{\mu}m$이었으며, 핵은 그 중 $4.3{\mu}m$로 정자두부의 대부분을 차지하고 있었으며, 핵의 후방부에서 전방부쪽으로 갈수록 폭이 가늘어지며 두부의 전체적인 모양은 탄환형(bull-shaped)을 취하고 있었다. 또한, 핵과 첨체는 Apical body에 의해 분리되어져 있었다. 정자경부는 basal plate, capitulum, segmented columns으로 구성되어져 있었다. 12~14개의 가는띠로 구성된 Segmented columns들의 밑부분은 중편부의 외측섬유와 연결되어져 있었다. 중편부의 미토콘드리아 초들은 나선상으로 배열되어져 있었으며, 그 수는 57개이었다. Satellite fibers는 외측섬유들 사이에 불규칙하게 관찰되어 졌으며, 중편부를 제외하고 다른 부분에서는 관찰되지 않았다. 중편부의 외측섬유는 1, 5, 6, 9번이 다른 것보다 크며, 꼬리의 축사구조는 전형적인 9+2구조이었으며, 미부의 미세소관들은 불규칙하게 배열되어져 있었다.