Immunoreactivity of Calcium-Binding Proteins in the Central Auditory Nervous System of Aged Rats

OBJECTIVE: While many factors contribute to aging, changes in calcium homeostasis and calcium related neuronal processes are likely to be important. High intracellular calcium is toxic to cells and alterations in calcium homeostasis are associated with changes in calcium-binding proteins, which confine free Ca2+. We therefore assayed the expression of the calcium binding proteins calretinin and calbindin in the central auditory nervous system of rats. METHODS: Using antibodies to calretinin and calbindin, we assayed their expression in the cochlear nucleus, superior olivary nucleus, inferior colliculus, medial geniculate body and auditory cortex of young (4 months old) and aged (24 months old) rats. RESULTS: Calretinin and calbindin staining intensity in neurons of the cochlear nucleus was significantly higher in aged than in young rats (p<0.05) The number and staining intensity of calretinin-positive neurons in the inferior colliculus, and of calbindin-positive neurons in the superior olivary nucleus were greater in aged than in young rats (p<0.05). CONCLUSION: These results suggest that auditory processing is altered during aging, which may be due to increased intracellular Ca2+ concentration, consequently leading to increased immunoreactivity toward calcium-binding proteins.

Anthropometric Study for Atlas According to Standardizd Korean Skeleton (2)-Sacrum, Hip Bone, and Lower Limb / 체질인류학회지

Current anatomy education in Korea has been dependent upon foreign textbooks and atlas. Various models and medical devices commonly used in Korea were imported from overseas. Now, it is necessary to design, produce and supply medical education, operative tools and treatment supportive devices customized to Korean human body and constitution. Accordingly, this is the time to assemble and deliver medical data to Korean population. Indivicess from the measurement for various types of bones were calculated, and the results were compared with data from foreign atlas and pictures. Individual drawings of bones from sacrum, hip bone and lower limb were made by using parameters we calculated, thus the atlas of Korean skeleton was constructed from artistic anatomical point of view. As a result, there were significant differences between Korean skeletons and the medical drawings from the oversea edition, and also we found numerous exaggerated and false dimensions without actual measurement. In the present study, we primarily focused on building musculoskeletal system of Korea population and set our goal as utilizing its graphic data for medical education in Korea. The present study would be the first study preparing theoretical foundations of Korean skeletal graphic system based on Korean body shape by comparison with other ethnic groups and foreign graphical models. Simultaneously, we conducted practical construction of the skeletal atlas by employing Korean standard measure data.

Anthropometric Study for Atlas According to Standardized Korean Skeleton (1)-Skull, Upper Limb / 체질인류학회지

Current anatomy education in Korea has been dependent upon foreign textbooks and atlas. Various models and medical devices from overseas were imported and commonly used in Korea, Now, we need to provide our own literatures and graphic data based on Korean population for student education. It is necessary to design, produce and supply medical education, operative tools and treatment supportive devices customized to Korean human body and constitution. Accordingly, this is the time to assemble and deliver medical data to Korean population. In this study, we primarily focused on building musculoskeletal system of Korea population and set our goal as utilizing its graphic data for medical education in Korea. It is first study preparing theoretical foundations of Korean skeletal graphic system based on Korean body shape by comparison with other ethnic groups and foreign graphical models. Simultaneously, we conducted practical construction of the skeletal atlas by employing Korean standard measures. Parameters from the measurement for various types of bones were calculated, and the results were compared with data from foreign atlas and pictures. Individual drawings of bones from skull, upper extremity was made by using parameters we calculated, thus the atlas of Korean skeleton was constructed from artistic anatomical point of view. As a result, there were significant differences between Korean skeletons and the medical drawings from the oversea edition. Because many foreign drawings used data from Caucasians only and there were numerous exaggerated and false dimensions without actual measurement. In conclusion, the result of the study is expected to provide fundamental data for building anatomical atlas about Korean human body structure.

Aberrant Expression of Transforming Growth Factor-beta1 in Endometrium of Infertile Women During the Window of Implantation / 대한산부인과학회잡지

OBJECTIVE: TGF-beta1 is a polypeptide which stimulates the growth of some mesenchymal cell types and inhibits the growth of epithelial cell types. Several studies have reported that TGF-beta1 is present in the endometrial tissue and it is also involved in a variety of physiological processes such as the implantation of the embryo into the endometrium. However, the expression of endometrial TGF-beta1 have not been well established in infertile women with endometriosis or hydrosalpinx having impaired endometrial receptivity. Therefore, the aim of this study was to determine the expression of endometrial TGF-beta1 in infertile women and to compare it with that of fertile women during the window of implantation. MATERIALS AND METHODS: Endometrial biopsies were performed during the window of implantation from 10 normal fertile women and 15 infertile women (5 unexplained infertility, 5 endometriosis and 5 tubal disease with hydrosalpinx). We performed immunohistochemistry using paraffin-embedded endometrial tissues. The staining intensity of TGF-beta1-immunostained section was assessed by semi-quantitative histologic score (H-score=Sum[Pi x (i +1)]; i: intensity 0-3, Pi: %cells for each given intensity) of 100 cells. RESULTS: In normal fertile women, the staining intensity of TGF-beta1 in the glandular epithelium was higher than that of stromal cells. But the stromal cells showed an irregularly distributed positivity. In infertile women, their expression patterns were similar to those in fertile women. There was no statistically significant difference in the staining intensity of TGF-beta1 between the glandular epithelium and stromal cell of women with unexplained infertility and that of fertile women. However, the staining intensity of TGF-beta1 in the glandular epithelium and stromal cell of women with endometriosis or hydrosalpinx were significantly higher (p<0.01) than those in fertile women. CONCLUSION: This study demonstrated that increased expression of endometrial TGF-beta1 in women with endometriosis or hydrosalpinx during the window of implantation may cause endometrial dysfunction during the implantation process such as endometrial-embryonic interactions and endometrial proteolytic activity.

Age-related Changes of Doublecortin Positive Cells in the Olfactory Bulb of the Rat / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: It is well-established that neurogenesis continues to occur during life in the restricted brain areas, such as the glomerular and granule cell layers of the olfactory bulb. Doublecortin is a protein required for neuronal migration in the developing brian and olfactrory bulb, and is expressed in postmitotic migrating and differentiating neurons during embryonic and postnatal development periods. We investigated age-related changes of doublecortin positive cells in the olfactory bulb of aged rat compared with new born rat. MATERIALS AND METHOD: Four months old (control group, n=7) and 24 months old (aged group, n=7) male Fischer 344 rats were used in this study. Olfactory bulbs of the rats were cut into 40 micro m-thick coronal sections and immunostained. We counted the doublecortin positive cells and neurofibrils, and measured the optical density of doublecortin by layer. We compared the results between the aged group and the control group. RESULTS: In the olfactory bulbs of aged group, we observed less doublecortin positive cells, neurofibrils and lower optical density than the control group. Doublecortin is expressed during life in migratory neuroblasts of the olfactory bulb of the rats. This expression is reduced in the aged group and the reduced degree is variable according to the layer. CONCLUSION: Age-related changes of the olfactory bulb are associated with the reduction of postnatal neurogenesis, especially during the migration and differentiaion stages. This changes result in reduction of interneurons of the olfactory bulb, and may be responsible for the decreased olfactory function.

The Effect of Food Restriction on the Expression of Neuropeptides in Olfactory Bulb of Rat / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Food restriction increases life span, reduces aging rate and affects a wide variety of biological functions. Neurotransmitter is a substance released from the axon terminal of a presynaptic neuron on excitation, which diffuses across the synaptic cleft to either excite or inhibit the target cell. The nervous system makes use of neurotransmitters for signaling. We investigated the change of immunoreactivity of neuropeptides in olfactory bulb of rat after food restriction. MATERIALS AND METHOD: Of 10-week old Sprague-Dawley rats used in this study. six rats were killed at the beginning of the experiment. Thirty rats which had been restricted to only half of their normal voluntary mean food intake (12 g instead of 24 g per day) were killed at 3 days, 1, 2, 4 and 9 weeks after food restriction (n=6 per time point). Olfactory bulbs of the rats were cut into 40 micrometer-thick coronal sections and immunostained. RESULTS: On the layers of glomerular, outer plexiform, granular cell and subependymal zone of olfactory bulb, immunoreactivities of cholecystokinin (CCK), tyrosine hydrolase (TH), and neuropeptide-Y (NPY) were increased at one week of food restriction. On all layers, immunoreactivities of CCK and TH were increased at 2 weeks of food restriction. However, immunoreactivity of NPY was increased on the only layers of glomerular, and granular cell of olfactory bulb at week 2. After 4th week, the immunoreactivity of NPY was the same as the control group; after 9th week, the mmunoreactivity of CCK and TH were the same as the control group. CONCLUSION: Our results demonstrated that CCK, TH, and NPY could be expressed in different manners on the layers of olfactory bulb of rat after food restriction, and that food restriction may improve olfactory sensitivity owing to the change of neuropeptides.

Expression of Calcium Binding Proteins in Olfactory Bulb of Rat: The Effect of Food Restriction / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Food restriction retards aging and increases mean and maximum life span in nearly all species tested thus far. Calcium-binding proteins show a heterogenous distribution in the mammalian central nervous system and are useful markers for identifying neuronal populations. These proteins have been implicated in the buffering and transport of calcium as well as in the regulation of various enzyme systems. We investigated the change of the immunoreactivity of calcium-binding proteins in olfactory bulb of rat after food restriction. MATERIALS AND METHOD: 10 weeks old Sprague-Dawley rat were used in this study. 6 rats were killed at the beginning of the experiment. 30 rats which were restricted food only half of their normal voluntary mean food intake (12 g instead of 24 g per day) were killed at 3 days, 1, 2, 4 and 9 weeks after food restriction (n=6 per time point). Olfactory bulbs of the rats were cut into 40 micro m-thick coronal sections and immunostained. RESULTS: On the layers of olfactory nerve, glomerular, outer plexiform, granular cell and subependymal zone, immunoreactivities of parvalbumin and calbindin were increased on food restriction week 1 and 2. However, parvalbumin at olfactory nerve layer and calbindin at granule cell layer failed to increase at week 2. Calretinin increased its immunoreactivity at olfactory nerve and outer plexiform layer at week 1. After restriction week 2, immunoreactivity of calcium-binding proteins was almost same as control. CONCLUSION: The results we obtained from restricted rats indicated that parvalbumin, calbindin and calretinin could be expressed by different manner and layer in olfactory bulb.

Seizure -Related Change of NADPH -diaphorase and Calcium Binding Protein Positive Neurons in the Brain of Rats / 체질인류학회지

Nitric oxide (NO) is a gaseous messenger that plays a role in neurotransmission, long term potentiation, depression and cerebral blood flow. Increases in intracellular calcium levels activate the enzyme NOS, and the NO released then diffuse to adjacent cells and activate guanylate cyclase. NO mediates the increase in cerebral blood flow during seizure activity. Therefore, the present study was aimed to investigate the change of NOS and calcium binding proteins in the rat cerebral cortex following seizure. Rats were injected with kainate (KA) and killed at 6 hours, 1, 3, 5 and 10 days after seizure. Expressional change of nNOS, calbindin D28k and parvalbumin was assessed by histochemistry, immunohistochemistry and microdensitometry in the rat brain. The intensity of the NADPH -d staining in rat cortical neurons showed a marked susceptibility to KA administration. At 6 hours and 3 days after seizure, the optical density of the NADPH -d staining was increased relative to the signal in saline treated control rats. At 5 and 10 days after seizure, the optical density of NADPH -d staining was not significantly different in most cortical regions compared to controls. In the hippocampus, the optical density of NADPH -d staining was highest at 5 days after seizure. The optical densities of calbindin D28k and parvalbumin positive neurons were various in the cerebral cortex, hippocampus and caudatoputamen during postseizure period. These results indicate that the calcium binding proteins investigated here are not essential for determining the activation of nNOS/NADPH -d positive neurons in the cerebral cortex and striatum.

Expression of leukemia inhibitory factor in endometrium of infertile women during the window of implantation / 대한산부인과학회잡지

OBJECTIVE: To determine the expression of endometrial leukemia inhibitory factor (LIF) in infertile women and to compare it with that of fertile women during the window of implantation METHODS: Endometrial biopsies were performed during the window of implantation from 10 normal fertile and 15 infertile women (5 unexplained infertility, 5 endometriosis and 5 tubal disease with hydrosalpinx). We performed immunohistochemistry using paraffin-embedded endometrial tissues. RESULTS: In fertile and infertile women, the staining intensities of LIF in the glandular epithelium were significantly higher (p<0.01) than those of stromal cells. There was no significantly difference in the expression of LIF between the glandular epithelium of infertile women with endometriosis or hydrosalpinx and those of fertile women. However, the staining intensities of LIF in the glandular epithelium of unexplained infertility patients were significantly lower (p<0.01) than those in fertile women. The staining intensities of LIF in stromal cell of women with unexplained infertility, endometriosis and hydrosalpinx were similar to those in fertile women. CONCLUSIONS: This study demonstrated that the glandular epithelial cells are more important sites of LIF secretion than stromal cells. The expression of endometrial LIF may be decreased in women with unexplained infertility during the window of implantation. Therefore, this result suggest that abnormalities of LIF expression in infertile women may underlie endometrial dysfunction in the adhesive phase of implantation.

A Study on Age-related change of the neuropeptide Y and NADPH-diaphorase positive neurons in the cerebral cortex and striatum of Apodemus agrarius / 대한해부학회지

Apodemus agrarius has been used for experimental purpose to identify the route of infection and pathogenesis of Korean hemorrhagic fever. However, despite the increasing amount of information being published at present about the physiologic and ecologic characteristics of Apodemus, few data are available about the morphologic findings in the brain. This study was aimed to clarify the change of NADPH-d and neuropeptide Y (NPY) associated with aging of the Apodemus. The number of NADPH-d positive or negative NPY neurons in the cerebral cortex and striatum were compared between two age groups of Apodemus (4 months and 24 months) after the histochemical and immunohis-tochemical staining. 1. The number of NADPH-d positive NPY neurons in cerebral cortex or striatum were not different between the two age groups. 2. The number of NADPH-d negative NPY neurons in cerebral region or caudatoputamen striatum were not different between the two age groups. 3. Most of NADPH-d or NPY neurons were bipolar or multipolar neurons with complex and long dendrites in the control group. 4. The NADPH-d or NPY neurons in cerebral cortex were more tortous and shorter than control in the aged group. These findings demonstrate that NADPH-d positive NPY neurons and NPY neurons do not seem to be change of age in cerebral cortex or striatum of Apodemus agrarius.

Sequential Change of Nitric Oxide Synthase in Rat Hippocampus after Kanic Acid-induced Seizure / 대한해부학회지

We have investigated the neural cell damage and the change in the expression of NOS in the rat hippocampus, one of the brain structures most vulnerable to seizures. Rats were injected with kainic acid (KA) and sacrificed 6 h, 1 d, 3 d and 6 d after KA administration. The neural cell damage and the expression pattern of NOS was studied using silver impregnation, NADPH-diaphorase (NADPH-d) histochemistry and reverse transcription-polymerase chain reaction (RT-PCR) analysis. Silver impregnation revealed that kainic acid caused pyramical cell damage which was most severe in the CA1/CA2 subfield and hilus and to a lesser degree in the CA3 region. The optical densities of NADPH-d-positive neurons in the CA1, CA3 and dentate gyrus (DG) regions of the hippocampus were shown to have increased in samples obtained 1 d and 3 d after injection of KA. The number of NADPH-d-positive neurons in the CA1 and CA3 regions of the hippocampus was shown to have decreased in samples obtained 3 d and 6 d after injection of KA. However, the number of NADPH-d-positive neurons in the DG region did not change significantly. The increase in the levels of nNOS, iNOS and eNOS mRNA reached maximal values in samples obtained 1 d after KA treatment. Our findings indicate that the KA-induced seizures induce neural cell damage, increase NOS activity and upregulate the expression of NOS mRNA, which suggests the possibility of a functional role of NOS in bringing about changes in the cells in the hippocampus following seizures.

Expressional Change of Endothelial Nitric Oxide Synthase in Rat Cerebral Cortex after Kainic Acid-Induced Seizure / 대한해부학회지

Administration of kainic acid (KA) results in induction of epileptiform activity and motor seizures. Nitric oxide (NO) mediates the increase in cerebral blood flow during seizure activity. However, the production site of NO has not been clearly defined. Recent studies showed that constitutive nitric oxide synthase may be induced under certain conditions. Therefore, this study was aimed to investigate the change in endothelial nitric oxide synthase (eNOS), neuropeptide Y (NPY) and vasoactive intestinal polypeptide (VIP) since these are involved in cerebral blood flow. Rats were treated with KA and killed at 6 hours, 1, 3, 6 and 12 days after seizure. Expressional changes were assessed by immunohisto-chemistry and RT-PCR. eNOS was detected in the blood vessels of the cerebral cortex of the control group, but was not detected in neurons. eNOS-positive neurons were induced in the cerebral cortex at 1 and 3 days after seizure and found in specific cortical areas, such as primary motor cortex, secondary motor cortex, primary somatosensory cortex, secondary somatosensory cortex, insular cortex, ectorhinal cortex, parietal association cortex, temporal association cortex, auditory cortex and visual cortex. The levels of eNOS mRNA increased at 1 and 3 days after seizure compared to controls. The staining intensity of eNOS-positive microvessels was elevated in samples obtained 1, 3, and 6 days after seizure compared to the control group. However, NPY- and VIP-positive neurons, and glial fibrillary acidic protein-positive astrocytes were not induced in the cerebral cortex after seizure. Therefore, specific neuroactive substances may be induced in the cerebral cortex after seizure. Nitric oxide, a free radical synthesized in the brain by NOS, is a messenger molecule that mediates vascular dilatation and neural transmission. Therefore, neurons showing induced eNOS-positivity and upregulated eNOS-positive microvessels may affect the cerebral blood flow and neuronal activity in the cerebral cortex after seizure.

Effect of Long-Term Food Restriction on Nitric Oxide Synthase-Positive Neurons in Rat Cerebral Cortex / 대한해부학회지

Nitric oxide is synthesized by cells containing the nitric oxide synthase (NOS), and NADPH-diaphorase (NADPH-d) is a selective histochemical marker for the NOS in the brain. The influence of feeding rats only half the amount of their normal daily intake of a purified diet on NOS was measured in the cerebral cortex by immunohistochemistry and NADPH-d histochemistry. iNOS was not detected in the cerebral cortex of control group. iNOS-positive neurons were induced in the cerebral cortex at 1 week after food restriction and found in specific cortical areas, such as primary motor cortex, secondary motor cortex, primary somatosensory cortex, secondary somatosensory cortex, parietal association cortex, auditory cortex, visual cortex, temporal association cortex and retrosplenial cortex. At 2 weeks after food restriction, iNOS-positive neurons were not found in all cortical areas. At 4 weeks after food restriction, iNOS-positive neurons were found in ectorhinal cortex and perirhinal cortex. In samples obtained 3 days after food restriction, the staining intensity of NADPH-d-positive neurons was decreased in most cortrical regions compared to the control group. At 1 week after food restriction, the staining intensity of NADPH-d was significantly increased in isocortical regions compared to the control group. At 9 weeks after food restriction, the staining intensity of NADPH-d was significantly decreased in all cortical regions. NO, a free radical synthesized in the brain by NOS, is a messenger molecule that mediates vascular dilatation and neural transmission. Therefore, neurons showing induced iNOS-positivity and upregulated NADPH-d-positive neurons may affect the neuronal activity in the cerebral cortex after food restriction.

Differential Effects of Aging on NADPH-diaphroase and Tyrosine Hydroxylase-Positive Neurons in Rat Brain Stem / 대한해부학회지

Nitric oxide is synthesized by neurons containing the nitric oxide synthase (NOS), and the nicotinamide adenine dinucleotide phosphate-diaphorase (NADPH-d) is a selective histochemical marker for the brain. Although, many reports have been published describing in detail the distribution of NADPH-d and tyrosine hydroxylase (TH), little information is available on possible morphological changes of NADPH-d and TH containing neurons during aging of the brain stem. Therefore, in this study, we assessed the effects of aging on the somal area and staining intensity of NADPH-d-positive and TH-immunoreactive (TH-IR) neurons in rat brain stem. In previous studies, enzyme activities of nitric oxide synthase (NOS) and NADPH-d were shown to be in an almost perfect correlation in the brain. Therefore, we evaluated the change of NADPH-d-positive neurons using a microdensitometrical method as a way of measuring changes in NOS activity. By using a double-labelling technique, we have shown that these two enzymes are located in separate neurons in most brain stem nuclei. In the aged group, the size of NADPH-d-positive neurons was not significantly changed in most nuclei of the brain stem compared to the control group. Staining intensity of NADPH-d-positive neurons was significantly changed in periaqueductal gray, superior colliculus and inferior colliculus in the aged group. In the aged rats, the size of TH-IR neurons was significantly changed in locus ceruleus and lateral paragigantocellular nucleus. Staining intensity of TH-IR neurons was significantly decreased in principal trigeminal nucleus, locus ceruleus and lateral paragigantocellular nucleus of the aged group. These results demonstrate that the NADPH-d-positive and TH-IR neurons are differently influenced by aging than the control group in the brain stem of rats. Difference in the changes of NADPH-d-positive neurons in brain stem nuclei suggest that neuronal NOS is regulated by different mechanims in the regions of the brain stem during aging.

Expression of Nitric Oxide Synthase and Neuropeptide Y Neurons in Rat Cerebral Cortex following Experimental Epilepsy / 대한해부학회지

Kainic acid (KA) is a frequently used excitotoxin in experimental epilepsy research. The excitatory effect of KA leads to generalized convulsions when KA is administered systematically at convulsant doses. Nitric oxide (NO) is a gaseous messenger that plays a role in neurotransmission. NO is formed by NO synthase (NOS) from arginine. Purification and molecular cloning led to identification of at least three NOS isoforms designated as neuronal NOS (nNOS), endothelial NOS (eNOS) and inducible NOS (iNOS). In the central nervous system, NO seems to be involved in plasticity and cytotoxicity. Therefore, the present study has investigated the congruence of mRNA induction and protein expression of nNOS, eNOS, iNOS and neuropeptide Y (NPY) following KA-induced seizure activity. The patterns of NOS and NPY were studied by NADPH-diaphorase histochemistry, immunohistochemistry and RT-PCR in the rat brain. NADPH-d displayed a region-specific induction pattern. Regions of NADPH-d induction were the motor cortex and perirhinal cortex of KA treated group. Whereas NADPH-d neurons were not induced in auditory cortex, visual cortex, cingulate cortex, insular cortex, retrosplenial cortex and ectorhinal cortex of KA treated group. NPY neurons were not induced in all cortical areas of KA treated group. Subsequent to cortical neuronal induction, NADPH-d activity was increased in constitutive NADPH-d neurons of 1 and 3 days group of KA treatment. 1 and 3 days following KA administration, increased levels of nNOS, eNOS and iNOS mRNA were seen in the cerebral cortex. However, the level of NPY mRNA was decreased in 6 and 12 days after seizure. These findings demonstrate that mRNAs encoding for NOS isoforms are translated into the respective proteins following excitotoxic seizure.

Expressional Change of Nitric Oxide Synthase and erbB4 in Rat Hippocampus after Seizure / 대한해부학회지

Nitric oxide has been considered to be an important modulator of the epileptic seizure response. Previous studies have mainly focused on the nitric oxide synthase (NOS) expressed in glial cells and vascular endothelial cells in the brain following seizures, while less data have been available reading the change of neuronal NOS (nNOS) produced in neurons. Polypeptide growth factors play a central role in a variety of environmentally induce structural changes in the cortex and hippocampus of adult brain. neuregulin is widely expressed in the central and peripheral nerve cells and Schwann cells, glia, oligodendrocytes and muscle cells, to control cellular proliferation, differentiation and migration. erbB family are the receptors of the neuregulin and consist of erbB2, erbB3 and erbB4. We have, therefore, investigated the change in the expression of nNOS and erbB4 in the rat hippocampus, one of the brain structures most vulnerable to seizures. Rats were injected with kainic acid (KA) and sacrificed 6 h, 1 d, 3 d and 6 d after KA administration. The expression pattern of nNOS and erbB4 was studied using reverse transcription-polymerase chain reaction analysis, NADPH-diaphorase (NADPH-d) histochemistry and immunohistochemistry. The increase in the level of nNOS reached maximal values in samples obtained 1 d after KA treatment. The optical densities of NADPH-d-positive neurons in the CA1 and dentate gyrus (DG) regions of the hippocampus were shown to have increased in samples obtained 1 d and 3 d after injection of KA. The number of NADPH-d-positive neurons in the CA1 regions of the hippocampus was shown to have decreased in samples obtained 3 d and 6 d after injection of KA. However, the number of NADPH-d-positive neurons in the DG region did not change significantly. We show that erbB4 immunoreactivity is increased in hippocampus, reaching maximal levels 3 d after KA treatment, some NOS neurons contain erbB4 protein. We propose that the survival of NOS neuron in the hippocampus after injection of KA is associated with expression of erbB4, neuregulin receptor.

Seizure-Related Change of NADPH-diaphorase and Calbindin D28k Positive Neurons in the Cerebral Cortex of Rats / 대한해부학회지

Administration of kainate (KA) results in the induction of epileptiform activity and limbic motor seizures. Nitric oxide (NO) is a gaseous messenger that plays a role in neural transmission, long term potentiation, depression and cerebral blood flow. NO is formed by NO synthase (NOS) from arginine. NO mediates the increase in cerebral blood flow during seizure activity. However, the production site of NO has not been clearly defined. Recent report showed that constitutive NOS may be induced under certain conditions. Therefore, the present study was aimed to investigate the change of NOS and calbindin D28k in the rat cerebral cortex following seizure. Rats were injected with KA and killed at 6 hours, 1, 3, 6 and 12 days after seizure. Expressional change of nNOS and calbindin D28k was assessed by histochemistry, immunohistochemistry and RT-PCR in the rat brain. Induced NADPH-d positive neurons were observed in the cerebral cortex of 1, 3, 6 and 12 days after seizure and found in specific cortical areas, such as motor cortex, somatosensory cortex, auditory cortex, visual cortex, ectorhinal cortex and perirhinal cortex. The level of nNOS mRNA increased at 1, 3, 6 and 12 days after seizure compared with control group. Induced calbindin D28k positive neurons were observed in motor cortex and somatosensory cortex 1 and 3 days after seizure. The level of calbindin D28k mRNA in the cerebral cortex was slightly decreased at 1 day after seizure. Therefore, in this study, the induced NADPH-d, calbindin D28k positive neurons and upregulated NADPH-d positive neurons may influence the cerebral blood flow and neuronal activity in the cerebral cortex during post-seizure period.

A Study on the Postnatal Development of NADPH-Diaphorase Positive Neurons in the Cerebral Cortex and Striatum of Apodemus agrarius / 대한해부학회지

Nitric oxide (NO) is a short lived membrane permeable gas, a recently identified neuronal messenger molecule, and implicated in several activity-dependent forms of synaptic plasticity. The histochemical staining of NADPH-diaphorase (NADPH-d) provides a simple method to select populations of neurons containing nitric oxide synthase (NOS), throughout the brain. The NADPH-d positive neurons, uniquely resistant to toxic insults and neurodegenerative diseases, have been colocalized with neurons in the brain and peripheral tissue containing NOS. Apodemus agrarius has been used for experimental purpose to identify the route of infection and pathogenesis of korean hemorrhagic fever. However, despite of the increasing publication at present about the physiologic and ecologic characteristics of Apodemus, a few data are available about the morphologic findings in the brain. In this study we used NADPH-d histochemistry to evaluate the distribution of neurons, contain NOS, on the postnatal development in cerebral cortex and striatum of the Apodemus agrarius. In the cerebral cortex of Apodemus agrarius, NADPH-d positive neurons were observed in all cortical layers, but were concentrated in V-VI layer. NADPH-d positive neurons of forebrain were more dense than other cortical regions. At 1 week after birth, NADPH-d positive neurons had short processes and immature features. In contrast, at 12 weeks after birth, NADPH-d positive neurons had longer and more complex processes than that of earlier ages. In the striatum, NADPH-d positive neurons were intensely stained, predominantly medium-sized neurons. They had multipolar or bipolar dendritic branches which belong to fusiform or stellate cell types in all groups. In addition, at 4 and 12 weeks after birth, NADPH-d positive neurons had long and complex fiber network. The number of NADPH-d positive neurons in the striatum was relatively decreased during postnatal development. However, the length and complexity of their processes were relatively increased after birth. Present results showed postnatal maturation patterns such as morphological features of NADPH-d positive neurons. These findings suggest that NADPH-d positive neurons will be reach adult level after 4 weeks of postnatal age. Therefore, this report provide the morphological evidence supporting the hypothesis that NO may be play a role in regulation of neuronal development and synaptic plasticity during postnatal development of Apodemus agrarius.

Age-related Changes of Mac1-positive Cell Distribution in the Thymus, Spleen and Popliteal Lymph Node in C57BL/6 Mice / 체질인류학회지

The following experiment was performed to clarify distributional change of the Mac1-positive cells at 1, 4, 8 ,12 and 40 weeks after birth. Thymuses, spleens and lymph nodes were removed and immunocytochemical staining using the specific Mac1 antibody was performed The results obtained from the present experiment were as follows : 1. Mac1-positive cell was absent at 1 week, they were increased by 4 weeks and decreased at 40 weeks in the thymus after birth. 2. There was no Mac1-positive cell in the marginal zone of the spleen at 4, 40 weeks, but they were shown at 8 weeks. 3. Mac1-positive cells were increased at 4 weeks in the subfollicular area of lymph nodes. There was no change of distribution in the lymph nodes. From the above results, we suggest that the age-related decrease of the immunity might be caused by decrease of Mac1-positive cells in the antigen-presenting area.

Expressional Change of Nitric Oxide Synthase and Vasoactive Intestinal Polypeptide in the Cerebral Cortex of Aged Rats / 체질인류학회지

This study examined the effects of aging on nitric oxide synthase (NOS) and vasoactive intestinal polypeptide (VIP)-positive neurons of the cerebral cortex in young (4 months) and aged (24 months) Wistar rats. Expressional change was assessed by histochemistry, immunohistochemistry and RT-PCR. Nitric oxide (NO) is synthesized by cells containing NOS, and NADPH-diaphorase is a selective histochemical marker for the NOS in the brain. In this study, the coexistence of NADPH-d and VIP was not found in the cerebral cortex of both groups. In the aged group, the number of NADPH-d positive neurons was not significantly changed in cerebral cortex than control groups. However, the number of VIP positive neurons was significantly decreased in cerebral cortex of the aged rats. NADPH-d and VIP positive neurons exhibited morphological characteristics of multipolar or bipolar in most neurons. In the aged group, NADPH-d and VIP positive nerve fibers were more irregular and tortuous compared to the control group. Perikaryal size of NADPH-d positive neurons was not significantly different in both groups. However, significant shrinkage of VIP positive neurons was found in the aged group. The enzyme activity of NADPH-d was increased in the aged group.The basal level of mRNA for NOS and VIP was detected in the cerebral cortex of control group. The expression level of iNOS mRNA was decreased in the aged group. The mRNA for nNOS, eNOS and VIP was not significantly different in both groups. The selective depletion and atrophy VIP positive neurons from the cerebral cortex of aged rats may reflect an increased vulnerability of VIP positive neurons to the aging process compared with NOS positive neurons.