Spatiotemporal expression of RCAN1 and its isoform RCAN1-4 in the mouse hippocampus after pilocarpine-induced status epilepticus

Regulator of calcineurin 1 (RCAN1) can be induced by an intracellular calcium increase and oxidative stress, which are characteristic features of temporal lobe epilepsy. Thus, we investigated the spatiotemporal expression and cellular localization of RCAN1 protein and mRNA in the mouse hippocampus after pilocarpine-induced status epilepticus (SE). Male C57BL/6 mice were given pilocarpine hydrochloride (280 mg/kg, i.p.) and allowed to develop 2 h of SE. Then the animals were given diazepam (10 mg/kg, i.p.) to stop the seizures and sacrificed at 1, 3, 7, 14, or 28 day after SE. Cresyl violet staining showed that pilocarpine-induced SE resulted in cell death in the CA1 and CA3 subfields of the hippocampus from 3 day after SE. RCAN1 immunoreactivity showed that RCAN1 was mainly expressed in neurons in the shammanipulated hippocampi. At 1 day after SE, RCAN1 expression became detected in hippocampal neuropils. However, RCAN1 signals were markedly enhanced in cells with stellate morphology at 3 and 7 day after SE, which were confirmed to be reactive astrocytes, but not microglia by double immunofluorescence. In addition, real-time reverse transcriptase–polymerase chain reaction showed a significant upregulation of RCAN1 isoform 4 (RCAN1-4) mRNA in the SE-induced hippocampi. Finally, in situ hybridization with immunohistochemistry revealed astrocytic expression of RCAN1-4 after SE. These results demonstrate astrocytic upregulation of RCAN1 and RCAN1-4 in the mouse hippocampus in the acute and subacute phases of epileptogenesis, providing foundational information for the potential role of RCAN1 in reactive astrocytes during epileptogenesis.

Quantitative Proteomic Analysis Reveals Impaired Axonal Guidance Signaling in Human Postmortem Brain Tissues of Chronic Traumatic Encephalopathy

Chronic traumatic encephalopathy (CTE) is a distinct neurodegenerative disease that associated with repetitive head trauma. CTE is neuropathologically defined by the perivascular accumulation of abnormally phosphorylated tau protein in the depths of the sulci in the cerebral cortices. In advanced CTE, hyperphosphorylated tau protein deposits are found in widespread regions of brain, however the mechanisms of the progressive neurodegeneration in CTE are not fully understood. In order to identify which proteomic signatures are associated with CTE, we prepared RIPA-soluble fractions and performed quantitative proteomic analysis of postmortem brain tissue from individuals neuropathologically diagnosed with CTE. We found that axonal guidance signaling pathwayrelated proteins were most significantly decreased in CTE. Immunohistochemistry and Western blot analysis showed that axonal signaling pathway-related proteins were down regulated in neurons and oligodendrocytes and neuron-specific cytoskeletal proteins such as TUBB3 and CFL1 were reduced in the neuropils and cell body in CTE. Moreover, oligodendrocyte-specific proteins such as MAG and TUBB4 were decreased in the neuropils in both gray matter and white matter in CTE, which correlated with the degree of axonal injury and degeneration. Our findings indicate that deregulation of axonal guidance proteins in neurons and oligodendrocytes is associated with the neuropathology in CTE. Together, altered axonal guidance proteins may be potential pathological markers for CTE.

The distribution of calbindin-D28k, parvalbumin, and calretinin immunoreactivity in the inferior colliculus of circling mouse / 대한해부학회지

The circling mice with tmie gene mutation are known as an animal deafness model, which showed hyperactive circling movement. Recently, the reinvestigation of circling mouse was performed to check the inner ear pathology as a main lesion of early hearing loss. In this trial, the inner ear organs were not so damaged to cause the hearing deficit of circling (cir/cir) mouse at 18 postnatal day (P18) though auditory brainstem response data indicated hearing loss of cir/cir mice at P18. Thus, another mechanism may be correlated with the early hearing loss of cir/cir mice at P18. Hearing loss in the early life can disrupt the ascending and descending information to inferior colliculus (IC) as integration site. There were many reports that hearing loss could result in the changes in Ca²⁺ concentration by either cochlear ablation or genetic defect. However, little was known to be reported about the correlation between the pathology of IC and Ca²⁺ changes in circling mice. Therefore, the present study investigated the distribution of calcium-binding proteins (CaBPs), calbindin-D28k, parvalbumin, and calretinin immunoreactivity (IR) in the IC to compare among wild-type (+/+), heterozygous (+/cir), and homozygous (cir/cir) mice by immunohistochemistry. The decreases of CaBPs IR in cir/cir were statistically significant in the neurons as well as neuropil of IC. Thus, this study proposed overall distributional alteration of CaBPs IR in the IC caused by early hearing defect and might be helpful to elucidate the pathology of central auditory disorder related with Ca²⁺ metabolism.

Clinicopathologic features of embryonal tumor with multilayered rosettes and gene analysis on chromosome 19q13.42 / 中华病理学杂志

<p><b>OBJECTIVE</b>To investigate the clinicopathologic features and 19q13.42 gene changes in embryonal tumors with multilayered rosettes (ETMR).</p><p><b>METHODS</b>Immunohistochemistry and fluorescence in situ hybridization (FISH) were performed in three ETMRs.</p><p><b>RESULTS</b>The average age of the patients were 34 months. Imaging revealed huge masses with inhomogeneous enhancement and two cases showed cystic lesions. Follow-up data showed 14 and 38 months survival in two children, the third had a recurrence 4 months after operation. Morphologically, the tumor was mainly composed of dense small primitive neuroepithelial cells in patchy or multilayer rosettes within a background of advanced neuronal differentiation, containing neurocytes, ganglion cells, and neuropil-like background. Immunohistochemical staining showed the neuronal marker, synaptophysin, was positive in differentiated areas. Nestin as a neural stem cell marker was immunoreactive in the primitive neuroepithelial cells including multilayered rosettes. Neurons with positive expression of NeuN were observed occasionally. Ki-67 index was up to 40%-80% in the undifferentiated cells and rosettes, but was only 1%-3% in the differentiated areas. CD99 was positive in perivascular papillary pattern areas in one case. 19q13.42 amplification was detected in more than 30% of tumor cells in all cases.</p><p><b>CONCLUSIONS</b>ETMR is a unique entity with distinctive clinical and pathological features. Chromosome 19q13.42 abnormality is valuable for confirming the diagnosis and for further treatment research.</p>

Canine model of ischemic stroke with autologous thrombus in three dogs; Magnetic resonance imaging features and histopathological findings / 동물의과학연구지

Ischemic stroke is the most common type of stroke in humans. The purpose of this study was to evaluate the diagnostic value of magnetic resonance imaging (MRI) in a canine model of stroke. Ischemic stroke was induced by using prepared autologous thrombus. The dogs were placed in lateral recumbency on the operation table and the cervical area of each dog was sterilized by using alcohol. After making a cervical incision, the common carotid artery and internal carotid artery (a branch of the common carotid artery that supplies an anterior part of the brain) were exposed. A 200 microL injection of the autologous thrombus prepared 24 hr prior to surgery was delivered with a 20 gauge venous catheter through an internal carotid artery. After successful delivery of the autologous thrombus, the venous catheter was removed, and the cervical incision was sutured. Neurologic signs including generalized seizures, tetraparesis, and altered mental status, were observed in all 3 dogs after induction of ischemic stroke and the signs manifested immediately after awakening from anesthesia. T1- and T2-weighted images and fluid-attenuated inversion recovery (FLAIR) images of the brain were acquired 1 day before and 1 day after surgery. On the day following ischemic stroke induction, MRI revealed multifocal lesions in the cerebral cortex and subcortex such as T1 hypointensity, T2 hyperintensity, FLAIR hyperintensity, and diffusion-weighted hyperintensity in all 3 dogs. Upon postmortem examination, ischemic lesions were found to be consistent with the MRI findings and they were unstained with 2% triphenyltetrazolium chloride. Histologic features of the earliest neuronal changes such as cytoplasmic eosinophilia with pyknotic nuclei were identified. Neuropil spongiosis and perivascular cuffing were also prominently observed at the infarcted area. The present study demonstrated the features of MRI and histopathologic findings in canine ischemic stroke models.

Os possíveis papéis da S100B na esquizofrenia / Potential roles of S100B in schizophrenia

Evidências científicas do aumento da concentração da proteína S100B no sangue de pacientes esquizofrênicos são muito consistentes. No passado essa informação era principalmente considerada como reflexo da disfunção astroglial ou da barreira hematoencefálica. MÉTODOS: Pesquisa de publicações no PubMed até o dia 15 de junho de 2011 visando estabelecer potenciais ligações entre a proteína S100B e as hipóteses correntes da esquizofrenia. RESULTADOS: A S100B está potencialmente associada com as hipóteses dopaminérgica e glutamatérgica. O aumento da expressão de S100B tem sido detectado em astrócitos corticais em casos de esquizofrenia paranoide, enquanto se observa uma redução da expressão em oligodendrócitos na esquizofrenia residual, dando suporte à hipótese glial. Recentemente, a hipótese da neuroinflamação da esquizofrenia tem recebido atenção crescente. Nesse sentido, a S100B pode funcionar como uma citocina secretada por células gliais, linfócitos CD8+ e células NK, levando à ativação de monócitos e microglia. Além disso, a S100B apresenta propriedades do tipo adipocina e pode estar desregulada na esquizofrenia, devido a distúrbios da sinalização de insulina, levando ao aumento da liberação de S100B e ácidos graxos do tecido adiposo. CONCLUSÃO: A expressão de S100B em diferentes tipos celulares está envolvida em muitos processos regulatórios. Atualmente, não pode ser respondido qual mecanismo relacionado à esquizofrenia é o mais importante

Scientific evidence for increased S100B concentrations in the peripheral blood of acutely ill schizophrenia patients is consistent. In the past, this finding was mainly considered to reflect astroglial or blood-brain barrier dysfunction. METHODS: Using Entrez, PubMed was searched for articles published on or before June 15, 2011, including electronic early release publications, in order to determine other potential links between S100B and current hypotheses for schizophrenia. RESULTS: S100B is potentially associated with the dopamine and glutamate hypotheses. Supporting the glial hypothesis, an increased expression of S100B has been detected in cortical astrocytes of paranoid schizophrenia cases, while decreased oligodendrocytic expression has been observed in residual schizophrenia. Recently, the neuroinflammation hypothesis of schizophrenia has gained attention. S100B may act as a cytokine after secretion from glial cells, CD8+ lymphocytes and NK cells, activating monocytes and microglial cells. Moreover, S100B exhibits adipokine-like properties and may be dysregulated in schizophrenia due to disturbances in insulin signaling, leading to the increased release of S100B and free fatty acids from adipose tissue. DISCUSSION: Dysregulation of pathways related to S100B appears to play a role in schizophrenia. However, S100B is expressed in different cell types and is involved in many regulatory processes. Currently, "the most important" mechanism related to schizophrenia cannot be determined

Primary Hepatic Neuroblastoma: A Case Report

Neuroblastoma is a malignant tumor of primordial neural crest origin. It usually develops along the sympathetic nervous system, such as the adrenal glands or paramedian sympathetic chain and metastasizes to the liver most frequently. However, a primary hepatic neuroblastoma has not been reported yet. Here, we report a case of 29-year-old woman who presented with a solitary hepatic mass. Grossly, the mass was large, creamy, rubbery firm, and showed focal hemorrhage and central cavitation. Microscopically, the tumor cells were arranged in small nests of spindle to ovoid cells with abundant neuropil. The neuroblastic nature of the tumor was confirmed by immunohistochemistry and electron microscopy. No extrahepatic mass was found, despite a thorough systemic survey such as chest and abdominopelvic computed tomography (CT) scans and a whole body positron emission tomography-CT study. To the best of our knowledge, this is the first report of a bona fide primary hepatic neuroblastoma.

Hipótesis epigenética de la esquizofrenia: bases moleculares y modelos experimentales / Epigenetic Hypothesis for Schizophrenia: Molecular bases and Experimental Models

Si bien la predisposición a desarrollar esquizofrenia ha sido, en parte, atribuida a un componente genético, la evidencia experimental de los últimos años sugiere que este trastorno puede ser el resultado de una aberración epigenética. De ahí que a las hipótesis hiperdopaminérgica e hipoglutamatérgica, se le sume la hipótesis epigenética de la esquizofrenia. Esta última propone que la fisiopatología de la enfermedad se sostiene en cambios en la expresión génica por una estructura aberrante de la cromatina, más que por cambios en la secuencia del ADN. De los múltiples blancos moleculares propuestos en la etiología de la enfermedad, cobra particular importancia la enzima ácido glutámico descarboxilasa, encargada de sintetizar el ácido γ - amino butírico (GABA), en especial la isoforma de 67 kDa, y la reelina, cuyos genes codificantes parecen estar hipermetilados en pacientes con esquizofrenia cuando se los compara con individuos sanos. Esto determina un menor nivel de expresión de la enzima y niveles disminuidos de GABA, lo que involucra íntimamente a este neurotransmisor en el desarrollo de la esquizofrenia.

Although the tendency to develop shizophrenia has partly been ascribed to a genetic component, experimental evidence gathered in recent years suggests that this disorder may be the producto of an epigenetic aberration. Hence, the hyperdopaminergic and hupoglutamatergic hypotheses add on the epigenetic hypothesis for shizophrenial. The latter proposes that the physiopathology of schizophrenia stems from changes in the gene expression, into an aberrant structure of the chromatin, rather than from DNA sequence variations. Oif the multiple molecular targets proposed in the etiology of shizophrenia, one which acquires particular significance is the enzyme, glutamic acid decarboxylase, which synthesizes Y-aminobutyric acid (GABA), especially 67-kDa isoform and reelin, whose codifying genes seem to be hypermethylated in patients with schizophrenia, as compared with healthy individuals. This determines a lower level of expression of the enzyme, as well as rduced GABA levels, which evidences the close relationship betweeen this neurotransmissor and the development of schizophrenia.

Efeitos da exposição pré-natal e pós-natal ao etanol no córtex cerebral de ratos: um estudo do neurópilo / Effects of prenatal and postnatal ethanol exposure in the cerebral cortex of rats: a study of neuropil

INTRODUÇÃO: Exposição pré-natal ao etanol é freqüentemente associada a microcefalia e atraso na migração celular. O mecanismo pelo qual o etanol induz seus efeitos no desenvolvimento do sistema nervoso não é muito bem entendido. OBJETIVOS: Avaliar o efeito da exposição crônica ao etanol sobre o córtex visual de ratos durante seu desenvolvimento. MATERIAL E MÉTODO: Ratos Wistar provenientes do acasalamento de 30 fêmeas, divididos nos grupos etanol (n = 10) - 3 g/kg/dia - e controle (n = 10), foram utilizados nesse experimento. Os ratos foram perfundidos e o encéfalo, dividido em três partes: anterior, médio e posterior. Os cortes obtidos do fragmento posterior foram expostos à rotina histológica e submetidos a diferentes técnicas de coloração. Na análise estatística foi utilizado o teste t para comparar os pesos encefálicos e corporais. Considerou-se como nível de rejeição de hipótese nula um valor de p < 0,05. RESULTADO: Houve redução de peso cerebral em diferentes períodos analisados, além de ectopia e heterotopia neuronal. Não se observou deposição de fibras. DISCUSSÃO/CONCLUSÃO: O etanol atua de maneira negativa no desenvolvimento dos ratos, incluindo alterações na migração neuronal e microcefalia. Essas alterações podem ajudar a explicar as disfunções relatadas na síndrome do alcoolismo fetal (SAF).

BACKGROUND: Prenatal exposure to ethanol is frequently associated with microencephaly and delayed cell migration. The mechanism by which ethanol affects the development of the nervous system is still not fully understood. OBJECTIVE: To evaluate the effect of chronic exposure to ethanol on the visual cortex of rats during their development. MATERIAL AND METHOD: Wistar rats, born from the mating of 30 females, were divided into two groups: those exposed to ethanol (n = 10) - 3 g/kg/day - and a control group (n = 10). The rats were perfused and brain was divided into three parts: anterior, middle and posterior. Slices taken from the posterior fragment were subjected to histological analysis routine and different staining techniques. A statistical analysis was carried out using t test to compare brain and body weight. A value < 0,05 was considered a rejection of null hypothesis. RESULTS: There was a reduction of brain weight in different analyzed periods. There were no fiber deposits. Ectopia and neuronal heterotopia were observed. DISCUSSION/CONCLUSION: Ethanol has a negative effect on the development of rats, including alterations in neuronal migration and microencephaly. These alterations may help to explain some of the dysfunctions reported in patients with fetal alcohol syndrome (FAS).

Immunohistochemical Study on the Distribution of Canonical Transient Receptor Potential Channels in Rat Cerebellum / 체질인류학회지

Channels formed by the transient receptor potential (TRP) family of proteins have a variety of physiological functions. In the present study, we examined the localization of canonical transient receptor potential channels (TRPCs) in rat cerebellum. Twelve adult (4~6 month old) Sprague-Dawley rats were examined in this study. We performed immunohistochemistry using specific antibodies against TRPCs to investigate the detailed and comparative distribution of six TRPCs in rat cerebellum. There was a high density of TRPC1, TRPC3, TRPC4, TRPC5 and TRPC7, with a much lower density of TRPC6 in the rat cerebellar cortex. The somatodendritic Purkinje cell areas were intensely stained with antiTRPC3, TRPC4, TRPC5 or TRPC7 antibodies, whereas the staining intensity of TRPC6 was relatively low in the Purkinje cell bodies. In the cerebellar nuclei, the cell bodies of cerebellar output neurons showed moderate TRPC1, TRPC3, TRPC5 and TRPC7 immunoreactivities, while TRPC6 immunoreactivity was observed in the surrounding neuropil. This study showing the differential localizations of TRPC channels in the cerebellum may provide useful data for the future investigations on the structural and functional properties of TRPCs.

enzyme histochemical map of the septal area of the rat

The septal area occupies a key position between the limbic telencephalon and the nuclei of the diencephalon. Its physiological role and connections have recently gained much attention. To describe the pattern of distribution of alpha-naphthyl acetate esterases, succinate dehydrogenase and cytochrome oxidase in the septal area correlate the results with the main neural connections of this area. Serial fresh frozen coronal sections from the septal area of the brains of 40 adult male rats were stained for the above-mentioned three enzymes. Alpha-naphthyl acetate esterases demonstrated the highest reactivity in the perikarya of the medial septal division. In the lateral septal division, the enzyme reactivity was particularly high in the neuropil. Succinate dehydrogenase was mainly localized in the neuropil. The lateral septal division revealed the highest reactivity. The perikarya of the medial septal division demonstrated high reactivity in contrast with the neuropil. Cytochrome oxidase localization was comparable with that of succinate dehydrogenase with only minor differences. A schematic map for each enzyme was revealed to provide detailed base-line knowledge for future perturbation and pathological studies

The Effect of Micro-Particles of Linoleic Acid Emulsion on the Blood-Brain Barrier in Cats

PURPOSE: The purpose of this study was to investigate the permeability change of the blood-brain barrier and the reversibility of the embolized lesions induced with a fat-emulsion technique by using magnetic resonance imaging (MRI), and we also wished to evaluate the resultant histologic findings in cat brains. MATERIALS AND METHODS: MR imaging was scheduled serially at 1 hour, day 1, day 4 and day 7 after infusion of linoleic acid-emulsion (0.05 ml linoleic acid+20 ml saline) to the internal carotid artery in 12 cats. Abnormal signal intensity or contrast enhancement was evaluated on diffusion-weighted images (DWIs), the apparent diffusion coefficient (ADC) maps, and gadolinium-enhanced T1-weighted images (Gd-T1WIs) at the stated times. MR imaging was stopped if the lesion shows isointensity and no contrast enhancement was observed at the acquisition time, and then brain tissue was harvested and examined. Light microscopic (LM) and electron microscopic (EM) examinations were performed. RESULTS:The embolized lesions appeared as isointensities (n=7) or mild hyperintensities (n=5) on DWIs, as isointensities (n=12) on the ADC maps, and as contrast enhancements (n=12) on Gd-T1WIs at 1 hour. The lesions showed isointensity on DWIs and the ADC maps, and as no contrast enhancement for all cats at day 1. The LM findings revealed small (< 1 cm) focal necrosis and demyelination in three cats. EM examinations showed minimal findings of small (< 3 micrometer) fat globules within the endothelial wall (n=10) and mild swelling of the neuropils (< 5 micrometer). Widening of the interstitium or morphologic disruption of the endothelial wall was not seen. CONCLUSION: Cerebral fat embolism induced by linoleic acid emulsion revealed vasogenic edema and reversible changes as depicted on the MR images. These results might help us to understand the mechanisms of fat on the blood-brain barrier, and this technique could be used as a basic model for research of the effects of drugs on the disrupted blood-brain barrier, and also as a research model for the chemotherapeutic effects of drugs of the brain tumors.

Morphology and Synaptic Pattern of Calretinin-immunoreactive Neurons in the Superficial Dorsal Horn of the Rat Spinal Cord / 대한해부학회지

The distribution and the synaptic relationships of calretinin-immunoreactive neurons were studied in the superficial dorsal horn of the rat spinal cord. Calretinin-immunoreactive neurons and fibers were found in all laminae of spinal cord. The densest staining of both cell bodies and fibers occurred in the superficial laminae. In lamina I, marginal cells and other neurons with small round cell bodies showed calretinin-like immunoreactivity. A calretinin-immunoreactive plexus of nerve fibers was also found in this lamina. Lamina II was densely packed with calretinin-immunoreactive neuronal elements. The outer layer of lamina II was primarily composed of calretinin-immunoreactive neurons with a round or oval shape, whereas in the inner layer dorsoventrally orientated labeled neurons with spindle-shaped cell bodies were observed. Densely labeled neuropils with punctate profiles were also seen. By electron microscopy most of the labeled punctate profiles appeared to be dendrites, but axonal profiles were also found in smaller numbers. Labeled dendritic profiles established symmetric or asymmetric synapses with unlabeled axons and labeled axons established primarily symmetric synaptic contacts with unlabeled dendrites. Synaptic contacts between two calretinin-immunoreactive processes were observed infrequently.

Extraventricular Cystic Neurocytoma

We report a case of extraventricular neurocytoma(left parietal lobe) in a young man presented with hemiparesis. The tumor, a radiologically well-circumscribed, cystic and enhancing mass, was partially removed. The patient, who received postoperative radiotherapy, is living well after 15 months of follow-up. Pathology showed a well-differentiated lesion composed of uniform, round cells with perinuclear halos in a neuropil background, immunohistochemically positive for neuronal markers. This was a cystic extraventricular neurocytoma(glio-neuronal tumor) arising from the left parietal lobe. Its features were consistent with neurocytoma pathologically and were different from those of intraventricular neurocytoma pathophysiologically. We outline the morphological and immunohistochemical evaluations necessary to recognize this rare tumor.

Morphological Studies on the Calbindin D-28K and Parvalbumin Immunoreactive Neurons in the Medulla Oblongata and Ventral Horn of the Spinal Cord Gray Matter after Spinal Cord Injury in Rats / 체질인류학회지

This study was examined and compared the immunocytochemical distribution of the two calcium-binding proteins calbindin D-28K and parvalbumin immunreactive neurons in the medulla oblongata and spinal cord after transection of spinal cord in rats. In this experiment, calbindin D-28K immnunoreactive neurons were mainly found in many pyramidal cells distributed medulla oblongata and spina1 cord of rats. Parvalbumin immunoreactive cells were demonstrated in all lamina of the gray matter of the spinal cord. These immunoreactive cells had the most high density in the severa1 nuclei of the ventra1 horn of the all segments of the spina1 cord. Calbindin D-28K neuropil labeling was strongly noted in spina1 all segments of the spinal cord. In contrast parva1bumin immunoreactive, little differences were found in distribution, size and morphology of calbindin D-28K cell body or neuropil staining in the spinal cord. The number of parvalbumin immunoreactive cells were more than twice in the medulla oblongata and spinal cord compared to the calbindin D-28K immunoreactive cells. Calbindin D-28K and parvalbumin-immmoreactive somata were round, ova1, spind1e and polygona1 in shape, and the immunoreactive neurons were unipolar, bipolar, multipolar and horizontal in shape. The diameters of the somata of the two immunoreactive neurons were 40 ~50 micrometer, respectively. Also dendrites of two immunoreactive neurons were densely arrayed in network. These results suggest that CB-IR and PV-IR most high density in the of the VII~X layers in the ventra1 horn of the all segments of the spina1 cord.

Seizure Induced Alteration of Microtubule Associated Proteins Immunoreactivities in the Mongolian Gerbil Striatum / 대한해부학회지

The present study involves a chronological and comparative analysis of both microtubule-associated protein 1A (MAP1A) and microtubule-associated protein 2 (MAP2) immunoreactivities in the striatum of both seizure resistant (SR) and seizure sensitive (SS) gerbil. The MAP1A immunoreactivity is weakly detected in perikarya of SR gerbils. However, MAP1A immunoreactivity is more accumulated in perikarya and dendrites in the pre-seizure group. At 30 min postictal, MAP1A immunoreactivity in the perikarya is decreased. At 3 hr postictal, MAP1A immunoreactivity in perikarya and dendrites is similarly decreased to the level of SR gerbils. The MAP2 immunoreactivity is weakly detected in the perikarya and dendrites of SR gerbils. However, MAP2 immunoreactivity is more accumulated in perikarya and dendrites. In particular, the neuropil between unstained fiber tracts obviously contains strong MAP2 immunoreactivity. At 30 min postictal, MAP2 immunoreactivity isn't almost observed in striatum. At 3 hr postictal, the MAP2 immunoreactivity is not different in the 30 min post -seizure groups but is only observed in the neuropil. However, at 12 hr postictal, the decrease of both MAP1A and MAP2 immunoreactivities had recovered to the pre -seizure level of SS gerbils. These results suggest that MAPs immunoreactivity in the striatum is different in SR and SS gerbils, and that this difference may be the results of seizure activity in this animal.

Immunohistochemical Studies on the Calbindin D -28K and Parvalbumin Positive Neurons in the Brain Stem and Spinal Cord after Transection of Spinal Cord of Rats / 체질인류학회지

This studies were examined and compared the immunohistochemical distribution of the two calcium -binding proteins calbindin D -28K and parvalbumin positive neurons in the brain stem and spinal cord after transection of spinal cord in rats. In this experiment, calbindin D -28K immunoreactive neurons were mainly found in many pyramidal cells distributed in the brain stem and spinal cord of rats. Calbindin D -28K neuropil labeling was strongly noted in brain stem and in spinal all segments of the spinal cord. In contrast to parvalbumin, little differences were found in distribution, size and morphology of calbindin D -28K cell body or neuropil staining in the brain stem and spinal cord. Parvalbumin immunoreactive cells were demonstrated in all lamina of the gray matter of the spinal cord. These immunoreactive cells had the most high density in the layer I and II dorsal horn and several nuclei of the ventral horn of the all segments of the spinal cord. These immunoreactive cells between the brain stem and spinal cord were quite different markedly in number, cell size and morphology The number of parvalbumin positive cells were more than twice in the brain stem and spinal cord compared to the calbindin D -28K positive cells. Calbindin D -28K and parvalbumin -immunoreactive somata were round, oval, spindle and polygonal in shape, and the positive neurons were unipolar, bipolar, multipolar and horizontal in shape. The diameters of the somata of the two positive neurons were 30 ~40 micrometer, respectively. Also dendrites of two positive neurons were densely arrayed in arborization.

Expression of Neuron Specific Enolase, Chromogranin, and Synaptophysin in Peripheral Neuroblastic Tumors

The presence and distribution of pan-neuroendocrine markers such as neuron-specific enolase (NSE), chromogranin (CG), and synaptophysin (SYP) were investigated by immunohistochemistry in 15 cases of neuroblastic tumors, including four cases of neuroblastomas, six cases of ganglioneuroblastomas, and five cases of ganglioneuromas. Three cases of normal sympathetic ganglion were used for the normal control group. NSE was observed in all cases and both in ganglion cells and in neuropils. NSE was detected not only in the majority of the neuroblasts showing signs of differentiation, but also in some poorly differentiated neuroblasts. All cases of neuroblastic tumors were positive for CG, however, some variability of staining intensity and distribution patterns were noted. CG was found mainly in differentiated neuroblasts with enlarged cytoplasm and nuclei along the periphery of the perikaria, and was also found in the perinuclear regions of some undifferentiated cells. SYP was positive in 9 of 11 cases. In all of the 9 cases, SYP was detected in some differentiating neuroblasts and differentiated neuroblasts, as well as the mature ganglion cells. However, it has scarcely stained in dot or granular pattern. Two CG-negative tumors were also negative for SYP. Our data indicate that antibodies against NSE and CG are helpful as a diagnostic aid for neuroblastic tumors.

Diffusion- and T2-weighted MR Imagings of Cerebral Infarction in Rabbit: Time Course of Imaging Findings and Histologic Correlation

PURPOSE: To correlate the serial findings obtained by diffusion- and T2-weighted imaging with histologicfind-ings obtained from 30 minutes to 31 days after the development of cerebral infarction in rabbits. MATERIALS AND METHODS: Nineteen male New Zealand white rabbits were subjected to intracerebral embolic infarction.Diffusion- and T2-weighted imagings were performed at 30 min, 2, 4 and 6 hours, and 1, 3, 5, 7, 11, 21 and 31days. Apparent diffusion coefficient (ADC) ratios and T2 signal intensity ratios of infarcted and normal brainwere calculated. Microphotographic or electron microscopic (EM) examinations were performed during hyperacute,acute and chronic infarctions. RESULTS: During hyperacute infarction, diffusion-weighted images showed highsignal intensity in the infarcted area, and ADC ratios ranged from 0.81 to 0.56. High signal intensity ondiffusion-weighted images continued until day 3, decreasing thereafter. The ADC ratio increased continuouslyafter day 1. High signal intensity on T2-weighted images was noted from 6 hours and continued until day 7,decreasing thereafter. Microphotographic findings at 6 hours were normal, but EM examination revealed cellularswelling with intact basement membrane, suggesting cytotoxic edema. During acute infarction, abnormal dilatationof the perineural space, cell destruction, and loosening of the neuropil matrix were revealed bymicrophotography. During chronic infarction, microphotographic and EM findings revealed liquefaction necrosis. CONCLUSION: These data indicate that in cases of hyperacute infarction, diffusion-weighted images reflectcy-totoxic edema more accurately than do T2-weighted images. A gradually increasing ADC ratio during the course ofinfarction may be associated with vasogenic edema and cell lysis.

Methylmercury intoxication and histochemical demonstration of NADPH-diaphorase activity in the striate cortex of adult cats

The effects of methylmercury (MeHg) on histochemical demonstration of the NADPH-diaphorase (NADPH-d) activity in the striate cortex were studied in 4 adult cats. Two animals were used as control. The contaminated animals received 50 ml milk containing 0.42 µg MeHg and 100 g fish containing 0.03 µg MeHg daily for 2 months. The level of MeHg in area 17 of intoxicated animals was 3.2 µg/g wet weight brain tissue. Two cats were perfused 24 h after the last dose (group 1) and the other animals were perfused 6 months later (group 2). After microtomy, sections were processed for NADPHd histochemistry procedures using the malic enzyme method. Dendritic branch counts were performed from camera lucida drawings for control and intoxicated animals (N = 80). Average, standard deviation and Student t-test were calculated for each data group. The concentrations of mercury (Hg) in milk, fish and brain tissue were measured by acid digestion of samples, followed by reduction of total Hg in the digested sample to metallic Hg using stannous chloride followed by atomic fluorescence analysis. Only group 2 revealed a reduction of the neuropil enzyme activity and morphometric analysis showed a reduction in dendritic field area and in the number of distal dendrite branches of the NADPHd neurons in the white matter (P<0.05). These results suggest that NADPHd neurons in the white matter are more vulnerable to the long-term effects of MeHg than NADPHd neurons in the gray matter.