• Molecules and Cells
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• v.38 no.6
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• pp.540-547
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• 2015

Attention deficit/hyperactivity disorder (ADHD) is one of the most common neurodevelopmental disorders, affecting approximately 5% of children. However, the neural mechanisms underlying its development and treatment are yet to be elucidated. In this study, we report that an ADHD mouse model, which harbors a deletion in the Git1 locus, exhibits severe astrocytosis in the globus pallidus (GP) and thalamic reticular nucleus (TRN), which send modulatory GABAergic inputs to the thalamus. A moderate level of astrocytosis was displayed in other regions of the basal ganglia pathway, including the ventrobasal thalamus and cortex, but not in other brain regions, such as the caudate putamen, basolateral amygdala, and hippocampal CA1. This basal ganglia circuit-selective astrocytosis was detected in both in adult (2-3 months old) and juvenile (4 weeks old) $Git1^{\check{s}/\check{s}}$ mice, suggesting a developmental origin. Astrocytes play an active role in the developing synaptic circuit; therefore, we performed an immunohistochemical analysis of synaptic markers. We detected increased and decreased levels of GABA and parvalbumin (PV), respectively, in the GP. This suggests that astrocytosis may alter synaptic transmission in the basal ganglia. Intriguingly, increased GABA expression colocalized with the astrocyte marker, GFAP, indicative of an astrocytic origin. Collectively, these results suggest that defects in basal ganglia circuitry, leading to impaired inhibitory modulation of the thalamus, are neural correlates for the ADHD-associated behavioral manifestations in $Git1^{\check{s}/\check{s}}$ mice.

• Applied Microscopy
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• v.31 no.4
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• pp.355-365
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• 2001

This study was performed to investigate the distribution and differentiation on the immunoreacted cells of the ChAT (choline acetyltransferase) at the Meynert basal nucleus of the forebrains in the growth periods of rat, using the immunohistochemistric method. According to the cell shape and the ratio of long axis vs short axis of cell soma, the ChAT antibody reacted nerve cells in the Meynert basal nucleus of the rats were classified into six types. In the adult rats, the FD (frequency distributions) of round, oval and elongated cells were maximum. The FD of these types were shown to be progressively decreased during the postnatal development. In addition, the FD of elongated nerve cells in were observed in the adult rats respectively. This was thought to be the same phenomenon as those in the round and oval cells . The total mean volume of ChAT antibody reacted cell somata was lowest in the PND (postnatal days) 7 rats and was highest in the PND 21 rats. But, those were decreased to the adult. These results suggest that ChAT antibody reacted nerve cells grow up to PND 21 and then, differentiate into the various types by neurites outgrowing. On the electron micrography, the adult rat forebrain cells were obtained to be well developed ribosomes, polysomes , rough endoplasmic reticula and mitochondria. The immunreactivities were observed in ribosomes, polysomes, rough endoplasmic reticula and outer membrane of mitochondria. Golgi complexes were poorly developed and not showed jmmunreactivity. The ribosomes , polysomes and endoplasmic reticula are considered to be closely related to the inter cellular localization and biosynthesis of the ChAT but not Golgi complex. According to the results in the present study, it is considered that the ChAT-immunoreacted nerve cells in the Meynert basal nucleus of the rat forebrains are differentiated throughout the postnatal development with following processes of changes; 1) the cholinergic nerve cells develop postnatally 2) cell soma volumes gradually increase during the early postnatal days 3) and then, cells differentiate into the various types by projecting the neurites to the appropriate area after PND 21.

• Korean Journal of Environmental Biology
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• v.38 no.2
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• pp.278-288
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• 2020

Rhodomonas salina is a phototrophic marine flagellate. We examined the ultrastructure of R. salina with particular attention to the flagellar apparatus by transmission electron microscopy and compared it with that of other cryptomonads reported previously. The major components of the flagellar apparatus in R. salina were a keeled rhizostyle (Rhs), a striated fibrous root(SR), a SR-associated microtubular root (SRm), a mitochondrion-associated lamella (ML), and three types of microtubular roots (9r, 4r, and 2r). The keeled Rhs originated near the proximal end of the dorsal basal body, passed near the nucleus and dissociated at the posterior end of the cell. The SR and SRm originated between two basal bodies and laterally extended to the right side of the cell. The ML originated between two basal bodies and extended to the left side of the cell. The 9r originated between the ventral basal body and the Rhs and extended toward the anterior dorsal lobe of the cell. The 4r originated near the 9r and extended toward the dorsal lobe with the 2r, which originated between two basal bodies. Here, the flagellar apparatus in R. salina is described, and the ultrastructure of the flagellar apparatus is compared among cryptomonad species.

• The Korean Journal of Malacology
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• v.27 no.1
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• pp.55-65
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• 2011

Some characteristics of germ cell differntiations during spermiogenesis and mature sperm ultrastructure in male Phacosoma japonicus were investigated by transmission electron microscope observations. The morphology of the spermatozoon of this species has a primitive type and is similar to those of other species in the subclass Heterodonta. Morphologies of the sperm nucleus and the acrosome of this species are the cylindrical type and cap shape, respectively. The spermatozoon is approximately 45-50 ${\mu}m$ in length, including a long curved sperm nucleus (about $3.70{\mu}m$ long with 45 $^{\circ}$ of the angle of the nucleus, an acrosome (about $0.55{\mu}m$ in length), and tail flagellum (about 42-$47{\mu}m$)The axoneme of the sperm tail shows a 9+2 structure. As some characteristics of the acrosomal vesicle structures, the basal and lateral parts of basal rings show electron opaque part (region), while the anterior apex part of the acrosomal vesicle shows electron lucent part (region). These characteristics of the acrosomal vesicle were found in the family Veneridae and other several families in the subclass Heterodonta. These common characteristics of the acrosomal vesicle in the subclass Heterodonta can be used for phylogenetic and systematic analysis as a taxonomic key or a significant tool. The number of mitochondria in the sperm midpiece of this species are four, as one of common characteristics appear in most species in the family Veneridae and other families in the subclass Heterodonta. However, exceptionally, only three species in Veneridae of the subclass Heterodonta contain 5 mitochondria. The number of mitochondria in the sperm midpiece can be used for the taxonomic analysis of the family or superfamily levels as a systematic key or tools.

• The Korean Journal of Zoology
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• v.36 no.4
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• pp.562-579
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• 1993

출생후 발생에 따른 흰쥐 전뇌 기저부의 Mevnert 기저핵(nucleus basalis of Mevnert)에서 신경성장인자 수용체(nerve growth factor receptor, NGFr)를 함유하는 신경세포의 면역반응성 및 분포, 세포형의 분류, 각 형별 출현율 및 세포 크기 그리고 세포소기관과 NGFr 면역반응과의 관계를 조사하였다. NGFr 면역반응 신경세포들은 출생후 초기 발생에서 세포질 뿐만 아니라 원형질 막에서도 면역반응을 보였으나, 성체에서는 세포질에서만이 면역반응을 보였다. NGFr 면역반응 신경세포는 형태학적 특징인 세포체의 모양과 장·단축의 비를 기준으로 5가지 형, 즉 1) 원형, 2) 난형, 3) 세장형. 4) 방추형, 5) 삼각형(또는 다각형)세포로 구분되었다 원형과 난형 세포는 출생후 0일에서 각각 15.4%. 50.7%의 높은 출현율을 보였으나, 발생이 진행되면서 점차 감소하여 성체에서 각각 7.8%, 28.6%의 출현율을 보였다 반면, 세장형, 방추형 및 삼각형세포는 출생후 0일에서 각각 22%, 2.6% 9.2%의 낮은 출현율을 보였으나, 발생이 진행되면서 지속적으로 증가하여 성체에서는 각각 29 9%, 5.2%, 28.5%의 높은 출현율을 보였다. 출생후 0일에서 신경세포체의 부피는 매우 작았으나(1,642mm3), 발생에 따라 점차 증가하여 14일, 21일에서는 성체에서보다 매우 컸다(각각 6.745, 6,755mm3) 원형 및 난형세포체의 부피는 21일에서(각각 7 955. 7.020mm3), 세장형 방추형 그리고 삼각형세포체의 부피는 14일에서 제일 컸다(각각 7,067, 6,237, 7,748 mm3) 대체적으로 삼각형세포체의 부피가 제일 컸으며, 방추형세포체의 부피가 제일 작았다. 출생후 순일에서의 전자현미경적 관찰에서 세포소기관중 조면소포체, Golgi체, multivesicular body 그리고 세포표면 원형질막이 강한 NGFr 면역반응을 보였다. 위의 결과들로 미루어 MGFr은 출생후 흰쥐 전뇌 기저부 Meynert 기저핵 신경세포의 분화 및 분포와 밀접한 관계를 갖는 것으로 생각된다.

• Applied Microscopy
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• v.34 no.2
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• pp.131-137
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• 2004

This study is observed the skin of the parrot fish, Oplegnathus fasciatus that related study of epidermal alternation with environmental and physiological change. It composed of supporting cells, unicellular glands and accessory cells. The supporting cells are classified into superficial cell, intermediated cell and basal cell. Superficial cell of epidermal layer is squamous or cuboidal and contain nucleus of ovoid type. And its free surface has many microridge which covered with glycocalyx. Intermediated cell is ovoid and has a nucleus of round shape. Basal cell is columnar, and nucleus is situated in the upper cytoplasm. Gland cells are classified into mucous cell and club cell. By the histochemical studies of the epidermal secretions the mucous materials react on blue in ABPAS (pH 2.5). Club cell is observed numerous vacuoles and microfilaments in the cytoplasm. The cytoplasm of chloride cells are occupied with numerous mitochondria. Pigment cells are classified into two type. The one contain pigment granules of electron dense, and the other contain reflecting platelets.

• Applied Microscopy
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• v.29 no.4
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• pp.479-491
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• 1999

This study was performed to investigate the distribution and differentiation of choline acetyltransferase (ChAT)-immunoreactive cells in the basal nucleus of Meynert of the postnatal and adult rat forebrains, utilizing techniques of immunocytochemistry. According to the cell shape and the ratio of long axis vs short axis of cell soma, the ChAT-immunoreactive nerve cells in the basal nucleus of Meynert of the adult rat were classified into six types. In the adult rat, the frequency distributions (FD) of round, oval, elongated, fusiform, triangular and polygonal cells were 9.4%, 35.5%, 32.1%, 5.9%, 9.1% and 8.0%, respectively. The FD of oval and round nerve cells on the postnatal day (PND) 14 were observed to be 18.7% and 51.5%, respectively. Those were shown to be progressively decreased during developmental process to the adult. Also, those of elongated and triangular nerve cells on the PND 21 were observed to be 30.4% and 10.1%, respectively. Those were shown to be same phenomenon a,1 those in the round and oval cells. Meanwhile, those of the triangular and polygonal nerve cells were progressively increased from the early postnatal stage to the adult. The total mean volumes of ChAT-immunoreactive cell somata in the PND 7 rat were the lowest $(1,083{\mu}m^3)$ and those in the PND 21 rat were shown to be the highest $(5,045{\mu}m^3)$. But in the adult, those were decreased to $(2,731{\mu}m^3)$. Those in the PND 21 rat were shown to be about 84.7% larger than those in the adult. On the electron micrography, the cell organelles such as ribosomes, polysomes, rough endoplasmic reticula (RER) and mitochondria were well developed in the PND 21 rat forebrains, but Golgi complexes were shown to be proliferating phase. Especially, ribosomes, polysomes and RER were immunoreactive in the tissues treated with 0.05% triton X-100. According to the observations in the present study, it is considered that the ChAT-immunoreactive nerve cells in the basal nucleus of Meynert of the rat forebrains are differentiated throughout the following processes of changes during the postnatal development: 1) increase of cell soma volumes with the differentiation of tell organelles and neurites, 2) increase in the FD of differentiated tell types and 3) cell schrinkage without cell loss. The ribosomes, polysomes and RER are considered to be closely related to the intracellular localization and biosynthesis of the ChAT but not Colgi complex.

• Korean Journal of Veterinary Research
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• v.24 no.1
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• pp.8-16
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• 1984

The work was conducted with tole purpose of investigation on the development pattern of epididymis in accordance with the growth of meat-type cockerels. 1. Histological features of various ductules in epididymis of the cockerel on the age of weeks were as follow: within 10 weeks after hatching rete testis and connecting ductules were well developed but efferent ductules were observed in immature form. During 10th to 20th week, the lining epithelium of various ductules in epididymis was in the developing stage near to the mature form. From 21th week, various ductules were abruptly matured. Lumen of rete testis was lined by simple squamous or simple columnar epithelial cells and that of efferent ductules, having many folds and being larger than any others, were lined by ciliated pseudostratified columnar epithelium with ciliated columnar cells, clear cells and basal cells were noted. Luminal epithelium of connecting ductules was composed of ciliated low pseudostratified columnar epithelial cells, ciliated columnar cells, clear cells and basal cells. The luminal surface of epididymal ducts was pseudostratified columnar epithelium and which was composed of high columnar cells and basal cells. 2. In the India ink absorption test, India ink granules were noted above the nucleus of some cells in the efferent ductules and the connecting ductules at 7 hours after administration of India ink to the mature epididymis, but not absorbed in the other ductules. The granules reactive to acid phosphatase were most abundant in some epithelial cells of efferent ductules and connecting ductules, especially above the nucleus of cells. The granules reactive to alkaline phosphatase were noted on the luminal border of efferent ductules. The granules reactive to PAS were scattered in the epithelial cells of efferent ductules and connecting ductules.

• The Korean Journal of Malacology
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• v.27 no.4
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• pp.377-386
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• 2011

The ultrastructures of germ cells during spermatogenesis and sperm morphology in male Mya arenaria oonogai, which was collected on the coastal waters of Samcheonpo, south coast of Korea, 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, appear on the spermatid nucleus, and then it becomes 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 cone shape, respectively. The spermatozoon is approximately $48-50{\mu}m$ in length including a curved cylinderical sperm nucleus (about $2.65{\mu}m$ long), an acrosome (about $0.64{\mu}m$ in length) and tail flagellum ($40-45{\mu}m$ 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 Myidae or some species of 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 $20^{\circ}$), as seen in some species of Veneridae (range from $0^{\circ}-80^{\circ}$). 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: the axoneme of the sperm tail flagellum consists of nine pairs of peripheral microtubules at the periphery and a pair of central doublets at the center.

• Development and Reproduction
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• v.17 no.2
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• pp.121-132
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• 2013

Ultrastructural characteristics of the germ cells and accessory cells in testis during spermatogenesis and taxonomic values of mature sperm morphology of Ruditapes philippinarum were investigated by the transmission electron microscope and scanning electron microscope observations. The testis is the diffuse organ that consists of branching acini containing developing germ cells and accessory cells associated with spermatogenesis. The morphology of the spermatozoon is of the primitive type and is somewhat different to those of other bivalves. The morphologies of the sperm nucleus type and the acrosome shape of this species have a cylinderical type and a modified cone shape, respectively. As some ultrastructural characteristics of the acrosomal vesicle, the peripheral parts of two basal rings show electron opaque part, while the apex part of the acrosome shows electron lucent part. These characteristics of 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. In particular, a cylinder-like nucleus of the sperm is curved. The spermatozoon is approximately $48-51{\mu}m$ in length, including a long acrosome (about $2.4{\mu}m$ in length), a curved sperm nucleus (about $3.40{\mu}m$ in length), and a tail flagellum. The axoneme of the sperm tail shows a 9+2 structure.