Outcome-based self-assessment on a team-teaching subject in the medical school / 대한해부학회지

We attempted to investigate the reason why the students got a worse grade in gross anatomy and the way how we can improve upon the teaching method since there were gaps between teaching and learning under recently changed integration curriculum. General characteristics of students and exploratory factors to testify the validity were compared between year 2011 and 2012. Students were asked to complete a short survey with a Likert scale. The results were as follows: although the percentage of acceptable items was similar between professors, professor C preferred questions with adequate item discrimination and inappropriate item difficulty whereas professor Y preferred adequate item discrimination and appropriate item difficulty with statistical significance (P<0.01). The survey revealed that 26.5% of total students gave up the exam on gross anatomy of professor Y irrespective of years. These results suggested that students were affected by the corrected item difficulty rather than item discrimination in order to obtain academic achievement. Therefore, professors in a team-teaching subject should reach a consensus on an item difficulty with proper teaching methods.

A Case of the Inferior Mesenteric Artery Arising from the Superior Mesenteric Artery in a Korean Woman

Anatomical variations of the inferior mesenteric artery are extremely uncommon, since the inferior mesenteric artery is regularly diverged at the level of the third lumbar vertebra. We found a rare case in which the inferior mesenteric artery arose from the superior mesenteric artery. The findings were made during a routine dissection of the cadaver of an 82-yr-old Korean woman. This is the tenth report on this anomaly, the second female and the first Korean. The superior mesenteric artery normally arising from abdominal aorta sent the inferior mesenteric artery as the second branch. The longitudinal anastomosis vessels between the superior mesenteric artery and inferior mesenteric artery survived to form the common mesenteric artery. This anatomical variation concerning the common mesenteric artery is of clinical importance, performing procedures containing the superior mesenteric artery.

Origin of the Retinal Oligodendrocyte in the Chicken Embryo / 대한해부학회지

Unlike other retinal cells, oligodendrocytes originate from the ventral midline of the third ventricle, and migrate to the retina at embryonic day 10 (E10) through the optic chiasm and the optic nerve in the bird. Recent studies have demonstrated that sonic hedgehog (shh), a differentiation factor for oligodendrocytes, was secreted by ganglion cells in the developing retina, indicating that microenvironment of the retina is sufficient for the generation of oligo-dendrocytes. Furthermore, it was revealed that uncommitted progenitors could differentiate into all cell types in the murine retina. On the basis of these reports, we proposed that a subpopulation of oligodendrocytes might generate in the retina in situ of the chick embryo. In order to verify our hypothesis, we injected the intraretinal space of chick embryos with a replication-defective retroviral vector (LZ12), and identified oligodendrocytes among LZ12-incorporated cells. Plp/dm-20 and pdgfr-alpha, oligodendrocyte specific transcripts were already expressed in the E5 retina. The expression of shh transcripts was also detected in the same stage. Analysis of the retina with intraretinal space injection demonstrated many clones consisting of various cell types arranged vertically through the retina. In addition, we found a few clones that had O4 +/-oligodendrocytes. In case of third ventricle injection, we found that LZ12-incorporated cells occurred in rows, the typical shape of interfascicular oligodendrocytes in the optic nerve, and were located in the nerve fiber layer adjacent to the ganglion cells in the retina. These cells were also labeled with TfBP antibody. These results indicate that retinal oligodendrocytes of birds are differentiated from retinal precursor cells, together with undifferentiated cells adjacent to the third ventricle.

Immunohistochemical Study on the TfBP Expression in the Embryonic Chick Cerebellum / 대한해부학회지

We have previously demonstrated that transferrin binding protein (TfBP) is a reliable marker for mature oligoden-drocytes (OLGs) in the avian central nervous system (CNS). Unlike mammalian CNS in which OLGs are generated largely postnatally, avian OLGs are differentiated during embryonic development of CNS. In this study, several aspects of TfBP(+/-) OLG development were immunohistochemically examined in the embryonic chick cerebellum : (1) change in shapes of immature cells with respect to time and to location within the cerebellum, (2) possible sites of origin, and (3) pathways of precursor cell migration. Our results indicate that TfBP expression gradually increases and extends from the deep portion of the white matter to gray matter with proportion to progress of cerebellar development. A few TfBP? cells were first observed in the deep portion of the cerebellum at E9. At E13, TfBP(+/-) cells were distributed evenly within the white matter. At E17, many TfBP(+/-) OLGs were located at granular layer and at the near place of Purkinje cell layer. At E20, a large number of TfBP cells appeared at the granular layer with a few in the molecular layer. Our data demonstrated distinct patterns of morphology and location of TfBP(+/-) OLGs in the cerebellum during development and suggest a role of TfBP in OLG development.

Experimental Study on the Expression of Striatal Dopamine Receptors in the Rat Model of Parkinsonism

No abstract available.

The Alteration of Avian Retinal Microglia Induced by Optic Nerve Transection / 대한해부학회지

Retina, a part of CNS, has served valuable and accessible tissue for elucidating the cellular properties of neurons and glia due to its similarity to brain. Unlike mammalian counterpart, avian retina is devoid of vessels and astrocytes. However little is known about glial reaction to neuronal injuries in this species. Therefore, this study was performed to investigate the microglial responses in the quail retina following neuronal injuries. The retinae from normal and optic nerve transected adult quails were studied immunohistochemically with anti-QH1, a marker known to be specific for microglia. In the normal retina, QH1-labeled microglial cells displayed typical feature of ramified (resting) form and were localized mainly in the inner plexiform layer. After optic nerve transection (ONT) morphology of microglial cells changed from the ramified to the amoeboid form. This feature of microglial cells maintained throughout the post operational periods until 28 days after ONT. Particularly, at 14 and 21 days after ONT amoeboid microglia displayed cell bodies with stout and bushy processes, suggesting active phagocytosis. The distribution pattern of microglia also changed in accord to ganglion cell degeneration: they gradually moved to layers of ganglion cells and optic nerve fibers where ganglion cell bodies and axons were under degeneration. This change of microglial distribution was most prominent at 14 days of ONT. The result of this study is generally consistent with that reported in mammalian counterpart and this similarity between the avascular avian retina and the vascularized mammalian counterpart suggests that processes of microglial activation, such as migration and phagocytosis, can occur in the vessel-free CNS tissue.

Expression of Guanine Deaminase in the Developing Rat Brain / 대한해부학회지

Guanine aminohydrolase (GAH; Guanine deaminase, EC 3.5.4.3) is an enzyme that has a role in purine catabolism. This enzyme produces xanthine and ammonia by hydrolysis of guanine, and xanthine is further degraded to uric acid and hydrogen peroxide by another enzyme, xanthine oxidase. Most of the enzymes involved in purine catabolism have been studied for their biological functions, physiological roles and amino acid sequences, and biochemical activity of GAH is known to be detected in various organs such as liver, kidney, small intestine and brain. Its activity is also known to be changed during brain development. In this study, we hoped to reveal expression pattern of GAH in developing rat brain by western blotting and immunohistochemistry. In western blotting, GAH immunoreactivity was not detected on 14-, 16- and 18-days-old fetal rat brains. Its reactivity was first detected from 20-days-old fetal rat brain and highly increased after birth. And it was maintained at steady level from 2 weeks after birth. In immunohistochemistry, no positive cells were found on 14- and 16-days-old fetal rat brain sections. A few GAH-immunoreactive cells appeared from 18-days-old fetal rat brain and they were localized at olfactory bulb, cerebral cortex, midbrain, pons and medulla. The 20-days-old fetal rat brain also showed immunoreactive cells at hippocampus and the staining intensity was still weak. Postnatal 2-days-old rat brain also showed immunoreactive cells at basal ganglia and the number of positive cells and staining intensity were increased. Thereafter, immunoreactivity appeared on many neuronal cells around various areas in the brain and nerve fibers also showed reactivity on postnatal brains. The number of positive cells decreased from 1 week after birth and a few positive cells were observed on olfactory bulb and cerebellum from 2 weeks after birth. In mature brain most of GAH were localized on nerve fibers and few positive cells could be found on olfatory bulb only. From these, we can suspect that GAH may have some functional relationship with nerve fibers.

Immunocytochemical study on the distribution of NOS-immunoreactive neurons in the cerebral cortex of aged rats / 대한해부학회지

Nitric oxide (NO) involvement has been demonstrated in mechanisms of synaptic plasticity, particularly in hippocampal long-term potentiation, a mechanism that underlies certain forms of learning and memory. Further, NO has been shown to regulate various neurotransmitters which play an important role in learning and memory. Several findings suggest that NO production may be decreased in the aged rat. Changes in the nNOS-containing neurons with aging were demonstrated by immunocytochemistry and in situ hybridization. NOS-immunoreactive cells in aged rats were present in all cortical areas and the hippocampus, and the pattern of distribution was similar to that of the control group. The number of NOS-immunoreactive cells in the cerebral cortex was significantly decreased in the aged rats, but the extent of changes was variable in each area, and ranged from mild decrease (50%). Severely decreased areas were the cingulate cortex, parietal cortex area 1, temporal cortex area 1, 2, 3, medial part of occipital cortex area 2, monocular and binocular part of occipital cortex area 1, entorhinal cortex, hippocampus proper, dentate gyrus and subiculum. Moderately decreased areas (30~50%) were frontal cortex area 1, 2, 3, parietal cortex area 2, forelimb, hindlimb, lateral part of occipital cortex area 2. Slightly decreased area was insular cortex. Morphologically, the number of dendritic branches seemed to be decreased in aged group and the length of dendrites of NOS-IR neurons showed a tendency to shorten. These results indicate the involvement of neuronal system containing NOS in the aging brain, and provide the first morphological evidence for the loss of NOS neurons in the cerebral cortex of the aged rats by immunocytochemistry. Further multidisciplinary investigations involving normal aging and neurodegenerative disease such as Alzheimer's disease are needed to clarify the importance of nitric oxide changes in the cerebral cortex with aging.

Spatial and temporal expression patterns of apoptosis-related genes in rat spinal cord during normal aging / 대한해부학회지

The pattern of distribution in rat spinal cord and changing pattern during normal aging of c-Fos, Bcl-2, Bax, and p53 expression were investigated by immunohistochemical staining. Male Sprague-Dawley rats at the age of one week, five months, and two years were studied. C-Fos immunoreactivity was observed diffusely in gray matters in neonatal rats, preferentially located in deep dorsal horn and around central canal. Compared with those of neonatal rats, immunoreactive cells decreased prominently in adult rats. In aged rats, these cells were not seen in any segments. In a transverse section, spatial expression of Bcl-2 and Bax proteins showed a diffuse distribution pattern with immunore-activity more prominent in the anterior horn. Continuing expression of these proteins was shown in each age group. In adult rats, Bcl-2 immunoreactivity was decreased drastically compared to that of neonatal rats. The immunoreactivity was higher in aged than in adult rats, but the number of immunoreactive cells was not different between aged and neonatal rats. The number of Bax-immunoreactive cells was greater in adult than in neonatal rats; in aged rats, it was similar with that of adult rats. The spinal cords of neonatal rats were not p53-immunoreactive, though p53-positive cells were detected in all segments of adult spinal cord. P53-positive cells were stained along the cellular margin, with a pale central portion. The pattern of p53 immunoreactivity in adult and aged rats was similar; the number of p53-positive cells, however, was higher in aged rats than in adult. In conclusion, we demonstrated that the expression patterns of c-Fos, Bcl-2, Bax, and p53 proteins in rat spinal cord change during normal aging for the first time.

Carbonic anhydrase II immunostaining in the cerebellum of postnatal mice / 대한해부학회지

The carbonic anhydrase II (CA-II) is specifically expressed in oligodendrocytes, the cells responsible for myelination in the central nervous system. However no direct evidence on relationship between myelin formation and CA-II immunoreactivity has been described. The aims of these studies are to investigate the relationship between CA-II and myelination during cerebellar development of mouse. Myelin staining was found on postnatal (P) 14, and its intensity increased in proportion to developmental age. CA-II positive oligodendrocytes were observed in the white matter of cerebellum on P 14 day. CA-II positive oligoden-drocytes also occured in the granular layer and Purkinje cell layers in the later stage of dvelopment. The parallel development in the CA-II expression and myelination during development suggests that CA-II in oligoendrocyte play a role to myelination.

Plastination: An Improved Method for Preservation of Pathology Specimens

The gross tissue specimens are a valuable aid to the teaching of pathology and anatomy. However, traditional methods for storage and handling of them are discouragingly difficult and, recently, minimal surgical resections as well as preoperative interventions make it more difficult to have instructive gross specimens. Plastination is a process of tissue preservation by impregnation with silicone polymers or epoxy resins. The process in our study involves dehydration by cryosubstitution in aceton, defatting, forced impregnation of silicon polymer in a vacuum, curing and finishing. We submitted 40 surgically resected specimens to plastination. The resulting specimens are odorless, relatively dry, durable, life-like, non-hazardous, maintenance-free, and do not deteriorate with time. Plastinated specimens are a useful adjunct to the teaching of pathology, particularly suited for use in small groups, and appropriate method of tissue preservation. They are much preferred to wet preparation and conventional pots by both students and teachers owing to their accessibility, superior illustrative powers, and comparative ease of interpretation.

Behavioral and Immunohistochemical Characterization of 6-Hydroxydopamine Induced Rat Models of Parkinson's Disease

There are several methods with which 6-hydroxy-dopamine is injected into the nigrostriatal pathway in rats for making models of Parkinson's disease. One is a complete lesion model in which A9 and A10 dopamine cells are destroyed, and the other one is a partial lesion model in which only A9 dopamine cells are destroyed. The aim of this study is to establish the model most suitable for transplantation of neural tissue. First, the behavioral change was investigated after dopamine releasing(amphetamine) or dopamine agonist(apomorphine) substances were injected. And then, immunohistochemical staining for tyrosine hydroxylase(TH) of the striatum and the substantia nigra was performed. Sixteen complete lesion models of Brundin, 4 complete lesion models of Perese, and 5 partial lesion models of Perese were made. The rotation response to amphetamine injection(5mg/kg, intraperitoneally) was checked 2 weeks after lesion making. For 6 rats, which showed rotation more than 7 turns/minute with amphetamine, the rotation response to subcutaneous injection of apomorphine was examined. Five complete lesion model of Brundin, 1 partial lesion model of Perese and 4 complete lesion model of Perese demonstrated rotation above 7 turns/minute in amphetamine test. Immunohistochemical staining of substantia nigra and corpus striatum for TH was faint on the lesioned side in rats which showed rotation above 7 turns/min in amphetaine-induced rotation test, irrespective of the kinds of model, while those ares of the normal side showed dense staining for TH. However, the results of immunohistochemical staining did not coincide with the results of rotation test by apomorphine.

Immunohistochemical Study on the Nitric Oxide Synthase in the Developing Rat Brain / 대한해부학회지

Nitric oxide(NO) is thought to play an important role in development and plasticity of brain. In this study, we aimed to examine the expression of neuronal NOS and NADPH-diaphorase (NADPH-d) activity in the developing rat brain. The results show that there is a great variation in the time of appearance of the earliest NOS containing cells depending on their location: At the 15th embryonic day weakly stained cells were present in caudate-putamen, and neurons in the sensory trigeminal nucleus and the solitary nucleus displayed an intense staining. The NOS neurons in orbital neocortex, bed nucleus of stria terminalis, paraventricular hypothalamic nucleus, lateral hypothalamic area and mammillary body appeared first at the 18th embryonic day. The supraoptic nucleus and superior and inferior colliculi also weakly labeled at the 18th embryonic day, At the loth embryonic day, positive cells appeared in horizontal limb of diagonal band, anterior olfactory nucleus and parafascicular thalamic nucleus. In the cerebellum, weak NOS staining was present in fibers and cells situated below Purkinje cert layer. The Purkinje cell layer displayed a weak, rather diffuse activity throughout the cerebellum at postnatal day 0. At the 4th postnatal day. the reaction product in the Purkinje cell layer became more distinct. At the 10th postnatal day, the inner part of molecular layer became populated by NOS positive basket cells, and the reaction products on the Purkinje cells began to disappear. The present results showed that NOS in the rat brain is expressed in different populations of neurons at different stages of development. This expression pattern of NOS suggests that NO may play a role in the developmental remodelling of the mammalian brain.

Study on the Expression of Vasoactive intestinal polypeptide, Vasopressin and Oxytocin mRNAs in the Rat Brain using Double in situ Hybridization Technique / 대한해부학회지

The technique of in situ hybridization using synthetic oligonucleotides labelled by non-radioactive method was developed to localize vasoactive intestinal polypeptide, arginine-vasopressin and oxytocin mRNAs in the rat brain. Also double in situ hybridization technique where combination of non-radioactive and radioactive probes were applied was developed to localize 2 neuropeptide mRNAs in single tissue section. The results were as follows; In non-radioactive in situ hybridization methods using digoxigenin-labelled oligonucleotide probe, alkaline-phosphates method using NBT and BCIP as substrates gave the best result that specific hybridization signals were observed. In radioactive in situ hybridization methods using 35S-labelled oligonucleotide probe, specific hybridization signals were observed in both nuclear track emulsion and X-ray film autoradiography. In double in situ hybridization methods using combination of 35S-labelled and digoxigenin-labelled oligonucleotide probes, specific hybridization signals were observed in the group where K5 emulsion was applied as nuclear track emulsion. The technique of in situ hybridization using digoxigenin-labelled oligonucleotide applied in this study will be useful as alternative for radioactive in situ hybridization technique. Moreover, combination of non-radioactive and radioactive labelled probes in double in situ hybridization technique will be a useful tool for the simultaneous localization of various mRNAs in single section for the study of various neurotransmitters, neuropeptides, receptors and signal transduction molecules.

Alteration of nigral iron and ferritin in 6-hydroxydopamine rat parkinsonian model

Iron-induced oxidative stress has been emphasized in the pathomechanism of Parkinson's disease (PD). Studies on the distribution of iron in the parkinsonian postmortem brain have demonstrated that iron deposition is selectively increased in substantia nigra pars compacta (SNc). This study was done to examine the alteration of nigral iron and ferritin in an animal model of parkinsonism and to understand the role of disturbed iron metabolism as a cause of PD. Hemiparkinsonian model was made by stereotaxically injecting 6-OHDA into the SN of Sprague-Dawley rats. We measured the content and distribution of iron by Perls' staining, and ferritin by immunohistochemical method in the SN. The H & E. cresyl violet, and immunocytochemical stain for glial fibrillary acidic protein, tomato lectin, and cabonic anhydrase-II were done to characterize the exact cell types. Iron content was markedly increased in the hemiparkinsonian model of SNc, not reticulate where normally more iron is distributed. The increased ferritin immunoreactivity was located in the same iron rich area of SNc. The cells with increased iron and ferritin were mainly astrocytes and microglias. 6-OHDA injection into SN resulted in increased free iron and ferritin immunoreactivity, suggesting that iron is important participant in oxidative cell death in PD. We think that increased ferritin in 6 OHDA lesioned SN argues against the hypothesis that decreased ferritin is a prerequisite for the free radical mediated death of nigral neurons in this model.

Electrophysiological properties of the neurons dissociated from the nucleus raphe magnus in postnatal rats

Neurons in the nucleus raphe magnus are involved in descending modulation of nociceptive transmission. In this study, we attempted to investigate electrophysiological properties of the NRM neurons dissociated from the postnatal rat medulla. The NRM neurons in the coronal slices of and the dissociated neurons from the postnatal rat medullae were immunohistochemically identified using antibody against serotonin. Relatively small number of neurons were positively stained in both preparations. The positively stained neurons displayed large cell body with double or multiple neurites. Using whole-cell patch clamp configuration ionic currents were recorded from the dissociated NRM-like neurons selected by criteria such as size and shape of cell body and cell population. Two types, high- and low-threshold, of voltage-dependent calcium currents were recorded from the dissociated NRM-like neurons. Some neurons displayed both types of calcium currents, whereas others displayed only high-threshold calcium current. Voltage-dependent potassium currents were also recorded from the dissociated NRM neurons. Some neurons displayed both transient outward and delayed rectifier currents but others showed only delayed rectifier current. These results suggest that there are at least two types of calcium currents and two types of potassium currents in the dissociated NRM neurons.

Vasopressin gene expression in the rat hypothalamus studied by in situ hybridization and immunocytochemistry / 대한해부학회지

No abstract available.

Studies on the effect of aging to the hypothalamo-neurohypophyseal endocrine cells and catecholaminergic neurons / 대한해부학회지

No abstract available.

Electron microscopic study on pseudorabies virus as a neurotracer / 대한해부학회지

No abstract available.

Morphological evidence of mitotic activity of mammotrophs and somatotrophs in monolayer cultured rat anterior pituitaries / 대한해부학회지

No abstract available.