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Purpose: To investigate the effect of cyanidin-3- O-glucoside (C3G) on a rat retinal degeneration (RD) model. Materials and methods: Experimental RD was induced in rats by the intraperitoneal injection of N-methyl- N-nitrosourea (MNU) at 50 mg/kg. C3G extracted from mulberry ( Morus alba L.) fruit (50 mg/kg) was orally administered, daily for 1, 2 and 4 weeks after MNU injection. The effects of C3G administration on MNU-induced RD retinas were histologically and functionally assessed by hematoxylin and eosin staining and electroretinography (ERG), respectively. The degree of retinal injury in C3G-administered RD rats was evaluated by immunohistochemistry with an antibody against glial fibrillary acidic protein (GFAP). The preferential protective effect of C3G on scotopic vision was examined by western blot analysis. Results: Marked loss of photoreceptors in the outer nuclear layer (ONL) was observed in RD rats at 2 and 4 weeks after MNU injection, while the ONL in the MNU-induced RD rats given C3G was relatively well preserved. Immunohistochemistry with anti-GFAP showed that retinal injury was also reduced in the retinas of the rats given C3G. Functional assessment by using ERG recordings showed that scotopic ERG responses were significantly increased in RD rats given C3G for 4 weeks ( p < 0.01) compared with that of untreated RD rats. In the RD rats given short-term C3G (for 1 and 2 weeks), the increase in ERG responses was not significant. In addition, western blot analysis showed that rhodopsin level in the C3G-administered RD retinas significantly increased compared to that in the non-administered RD retinas ( p < 0.05), whereas red/green opsin level did not show any significant difference. Conclusions: Long-term administration of C3G extracted from mulberry fruit could structurally reduce photoreceptor damage and functionally improve scotopic visual functions in the RD rat model induced by MNU. [ABSTRACT FROM AUTHOR]

Calcium (Ca2+)-activated chloride (Cl−) channels (CaCCs) play a role in the modulation of action potentials and synaptic responses in the somatodendritic regions of central neurons. In the vertebrate retina, large Ca2+-activated Cl− currents (ICl(Ca)) regulate synaptic transmission at photoreceptor terminals; however, the molecular identity of CaCCs that mediate ICl(Ca) remains unclear. The transmembrane protein, TMEM16A, also called anoctamin 1 (ANO1), has been recently validated as a CaCC and is widely expressed in various secretory epithelia and nervous tissues. Despite the fact that tmem16a was first cloned in the retina, there is little information on its cellular localization and function in the mammalian retina. In this study, we found that ANO1 was abundantly expressed as puncta in 2 synaptic layers. More specifically, ANO1 immunoreactivity was observed in the presynaptic terminals of various retinal neurons, including photoreceptors. ICl(Ca) was first detected in dissociated rod bipolar cells expressing ANO1. ICl(Ca) was abolished by treatment with the Ca2+ channel blocker Co2+, the L-type Ca2+ channel blocker nifedipine, and the Cl− channel blockers 5-nitro-2-(3-phenylpropylamino) benzoic acid (NPPB) and niflumic acid (NFA). More specifically, a recently discovered ANO1-selective inhibitor, T16Ainh-A01, and a neutralizing antibody against ANO1 inhibited ICl(Ca) in rod bipolar cells. Under a current-clamping mode, the suppression of ICl(Ca) by using NPPB and T16Ainh-A01 caused a prolonged Ca2+ spike-like depolarization evoked by current injection in dissociated rod bipolar cells. These results suggest that ANO1 confers ICl(Ca) in retinal neurons and acts as an intrinsic regulator of the presynaptic membrane potential during synaptic transmission. [ABSTRACT FROM AUTHOR]

ABSTRACT Acorn-derived foods are commonly marketed in Korea, but their beneficial health effects have not been extensively explored. The aim of this study was to investigate the anti-inflammatory and antiasthmatic effects of an ethanol extract (AEx) from acorn ( Quercus acutissima CARR.) in murine macrophage RAW264.7 cells and ovalbumin (OVA)-induced asthma model mice. The AEx at concentrations less than 100 µg/mL significantly, dose dependently attenuated the production of nitric oxide and the expression of inducible nitric oxide synthase, cyclooxygenase-2 and interleukin-1β (IL-1β) in RAW264.7 cells. The AEx (100 or 300 mg/kg/day) also inhibited the production of tumor necrosis factor-α and T-helper 2 (Th2) type cytokines (IL-4 and IL-13) in both the lung tissues and bronchoalveolar lavage fluid of the OVA-induced asthma model mice. These results suggest that the AEx has suppressive effects on asthma through its anti-inflammatory action both in vitro and in vivo. PRACTICAL APPLICATIONS AEx may be useful for preventing inflammatory diseases, such as allergic asthma, and may thus be effectively used as a natural anti-inflammatory ingredient in health food or pharmaceuticals. [ABSTRACT FROM AUTHOR]

The aims of this study were to investigate the sex discriminating potential of the talus in Koreans and compare this with other analyses in different populations. Statistical analyses were performed using data from nine measurements acquired from 140 tali (70 men, 70 women). The talus of Koreans is dimorphic between sexes in all measurements ( p < 0.01). Discriminant function equations were generated by univariate, multivariate, and stepwise methods with a range of accuracy from 67.1 to 87.1%. Stepwise equations of other populations did not discriminate the sex of the Korean sample as accurately as each equation's own accuracies. The variables with high accuracy in this study are useful for sex determination of Koreans on the basis of confirmation of population specificity. [ABSTRACT FROM AUTHOR]

Doublecortin (DCX) is microtubule-associated protein and is required for neuronal migration, differentiation and plasticity. In the retina, it is highly expressed between embryonic day 18 (E18) and E20, and is poorly expressed postnatally. In this study, we investigated the expression and cellular localization of DCX in the rat retina following ischemia induced by transiently increasing the intraocular pressure. While DCX immunoreactivity in control retinas was restricted to the outer border of the inner nuclear layer, it appeared in horizontal cell somata and processes in affected retinas. Quantitative evaluation by immunoblotting confirmed that DCX expression continuously increased after ischemia-reperfusion and showed 370% of control protein levels at 4 weeks after ischemic insult. These results suggest that the DCX in horizontal cells might play a role in neurite remodeling or modulating other neurons in ischemic rat retinas. [ABSTRACT FROM AUTHOR]

To investigate a potential role of osteopontin (OPN) in developing rat brain, the expression of OPN mRNA and protein in the developing rat brain relative to the distribution of brain macrophages was investigated using in situ hybridization and immunohistochemistry, and the phagocytic capability of OPN-expressing cells was accessed using rhodamine isothiocyanate (RhIc) as a tracer. OPN-expressing cells appeared from embryonic day 16. During the first week of postnatal life, OPN-labeled cells increased markedly, and peaked around P7, then declined and had completely disappeared by the end of the second postnatal week. The spatiotemporal distribution pattern of OPN mRNA closely matched that of OPN protein. Their morphology and localization were compared with those of cells expressing the established microglial marker OX-42 in adjacent sections, and double-labeling studies demonstrated that OPN was localized to the amoeboid microglia which stain with the lectin GSI-B4, another marker for microglia. Furthermore, OPN-labeled cells were confirmed to be active phagocytes emitting RhIc fluorescence indicating that the tracer into the brain tissues was engulfed by phagocytosis. Therefore, these results provide the first evidence that OPN is transiently expressed in active brain macrophages in the embryonic and early postnatal brain, and suggest that OPN may contribute to the migration and phagocytic function of brain macrophages in the developing brain. [ABSTRACT FROM AUTHOR]

Connexin 36 (Cx36) is a channel-forming protein found in the membranes of apposed cells, forming the hexameric hemichannels of intercellular gap junction channels. It localizes to certain neurons in various regions of the brain including the retina. We characterized the expression pattern of neuronal Cx36 in the guinea pig retina by immunocytochemistry using specific antisera against Cx36 and green/red cone opsin or recoverin. Strong Cx36 immunoreactivity was visible in the ON sublamina of the inner plexiform layer and in the outer plexiform layer, as punctate labelling patterns. Double-labelling experiments with antibody directed against Cx36 and green/red cone opsin or recoverin showed that strong clustered Cx36 immunoreactivity localized to the axon terminals of cone or close to rod photoreceptors. By electron microscopy, Cx36 immunoreactivity was visible in the gap junctions as well as in the cytoplasmic matrices of both sides of cone photoreceptors. In the gap junctions between cone and rod photoreceptors, Cx36 immunoreactivity was only visible in the cytoplasmic matrices of cone photoreceptors. These results clearly indicate that Cx36 forms homologous gap junctions between neighbouring cone photoreceptors, and forms heterologous gap junctions between cone and rod photoreceptors in guinea pig retina. This focal location of Cx36 at the terminals of the photoreceptor suggests that rod photoreceptors can transmit rod signals to the pedicle of a neighbouring cone photoreceptor via Cx36, and that the cone in turn signals to corresponding ganglion cells via ON and OFF cone bipolar cells. [ABSTRACT FROM AUTHOR]

The expression and cellular localization of neuronal nitric oxide (NO) synthase (nNOS) were studied in the rabbit spinal cord following ischemic injury induced by clamping the descending aorta. In the normal spinal cord, nNOS immunorcactivity was localized to certain motor neurons located in the margin of the ventral horn. Following transient ischemia, immunoreactive spinal neurons increased in numlber, peaking five days after reperfusion. Quantitative evaluation by western blotting showed that nNOS peaked at 180% of control levels five days after reperfusion and decreased to 120% of controls by 14 days. These findings suggest that overproduced NO may act as a neurotoxic agent in the ischemic spinal cord. [ABSTRACT FROM AUTHOR]

Using immunocytochemistry, we have investigated the localization of CD15 in the rat retina. In the present study, two types of amacrine cell in the inner nuclear layer (INL) and some cells in the ganglion cell layer were labeled with anti-CD15 antisera. Type 1 amacrine cells have large somata located in the INL, with long and branched processes ramifying mainly in stratum 3 of the inner plexiform layer (IPL). Type 2 cells have a smaller soma and processes branching in stratum 1 of the IPL. A third population showing CD15 immunoreactivity was a class of displaced amacrine cells in the ganglion cell layer. The densities of type 1 and type 2 amacrine cells were 166/mm2 and 190/mm2 in the central retina, respectively. The density of displaced amacrine cells was 195/mm2. Colocalization experiments demonstrated that these CD15-immunoreactive cells exhibit γ-aminobutyric acid and neuronal nitric oxide synthase (nNOS) immunoreactivities. Thus, the same cells of the rat retina are labeled by anti-CD15 and anti-nNOS antisera and these cells constitute a subpopulation of GABAergic amacrine cells. [ABSTRACT FROM AUTHOR]

We investigated the morphological changes of horizontal cells after postnatal photoreceptor degeneration in the developing FVB/N mouse retina, using immunocytochemistry with anti-calbindin D-28K. From postnatal day 14 (P14) onwards, processes emerging from horizontal cells descend into the inner plexiform layer (IPL) and ramify mainly in stratum 1 of the IPL. Electron microscopy revealed that the descending processes make synaptic contacts with bipolar cells in the outer plexiform layer. Our results clearly demonstrate that loss of photoreceptor cells induces the reorganization of horizontal cell processes in the retinas of FVB/N mice as they mature. [ABSTRACT FROM AUTHOR]

We examined dopaminergic neurons in the guinea pig retina; antisera against tyrosine hydroxylase (TH), dopamine β-hydroxylase (DBH), phenylethanolamine N-methyltransferase (PNMT) and an antiserum against γ-aminobutyric acid (GABA) were used. In the present study, two types of amacrine cells were labeled with an anti-TH antiserum. However, no DBH and PNMT immunoreactivities were seen. The type 1 cell had a larger-sized soma located in the inner nuclear layer with processes ramifying mainly in stratum 1 of the inner plexiform layer (IPL). The type 2 cell had a smaller-sized soma and processes branching in stratum 3 of the IPL. The mean densities were 56.4±11.5/mm2 for the type 1 cell and 166.6±30.3/mm2 for the type 2 cell. Double immunocytochemistry using an antiserum against GABA revealed that while none of the type 1 cells showed GABA immunoreactivity, all of the type 2 cells displayed GABA immunoreactivity. Our results suggest that, in the guinea pig retina, the type 1 amacrine cells are pure dopaminergic and the type 2 cells are dopaminergic elements that use GABA as their second transmitter. [ABSTRACT FROM AUTHOR]

Abstract Doublecortin is 40 kDa microtubule-associated phosphoprotein required for neuronal migration and differentiation in various regions of the developing central nervous system. We have investigated the expression and cellular localization of doublecortin in the developing rat retina using immunocytochemistry and Western blot analysis. The expression of doublecortin was high from embryonic day 18 (E18) until E20 and was low during the postnatal period. The doublecortin immunoreactivity first appeared in a few radially orientated cells in the mantle zone of the primitive retina at E15. From E16 onward, the immunoreactivity appeared in two different regions: the inner part of the retina and middle of the neuroblastic layer. In the inner part, the somata of cells in the ganglion cell layer, in the distal row of the neuroblastic layer and profiles in the inner plexiform layer showed doublecortin immunoreactivity up to postnatal day 1 (P1). Afterwards, the doublecortin immunoreactivity persisted in the inner plexiform layer until P15, although the intensity decreased gradually with the maturation of the retina. In the middle of the neuroblastic layer, doublecortin immunoreactivity appeared in the radially orientated cells. These cells transformed into horizontal cells. The doublecortin immunoreactivity persisted in these cells up to P21. Given these results, doublecortin may play an important role in the migration and differentiation of specific neuronal populations in developmental stages of the rat retina. [ABSTRACT FROM AUTHOR]

Presents a correction to the corresponding author of the article entitled "Reorganization of Horizontal Cell Processes in the Developing FVB/N Mouse Retina," published in the February 2002 issue of "Cell & Tissue Research."