Taurine and GABA in the rat retina during postnatal development

Lake, Norma

doi:10.1017/s0952523800001619

Cited by 46 publications

(31 citation statements)

References 22 publications

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“…The increase in GABA immunoreactivity observed in some amacrine cells and the localisation of GABA in horizontal cells from birth may be explained by an early activation and increased GAD activity in the RCS rat retinas compared with the control. During and after degeneration, GABA immunoreactivity appeared similar to that previously described in the normal rat retina (Mosinger et al, 1986;Osborne et al, 1986;Lake, 1994;Fletcher and Kalloniatis, 1996b). At both PND 25 and PND 60, GABA was localised in amacrine and displaced amacrine cells and a subpopulations of ganglion cells (Fig.…”

Section: Localisation Of the Amino Acid Neurotransmitters And Substansupporting

confidence: 78%

“…These data indicate that taurine is localised in the retina early in development, in a similar fashion to the normal rat and rabbit retina (Lake, 1994;Pow et al, 1994;Fletcher and Kalloniatis, 1996b). Development of photoreceptors, as determined by taurine immunoreactivity appears to occur in a similar manner to that of normal retinas.…”

Section: Localisation Of the Amino Acid Neurotransmitters And Substansupporting

confidence: 55%

“…Development of GABA immunoreactivity in the RCS rat retina was distinct from that of the normal rat retina (Lake, 1994;Fletcher and Kalloniatis, 1996b). At birth, GABA was localised in a small population of amacrine cells (Fig.…”

Section: Localisation Of the Amino Acid Neurotransmitters And Substanmentioning

confidence: 90%

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Neurochemical development of the degenerating rat retina

Fletcher

Kalloniatis

1997

J. Comp. Neurol.

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The Royal College of Surgeons' (RCS) rat is an experimental model for a group of hereditary retinal diseases commonly called retinitis pigmentosa. We used postembedding immunocytochemistry to determine the localisation of glutamate, gamma-aminobutyric acid (GABA), glycine, aspartate, glutamine, taurine, and arginine in the RCS rat retina during postnatal development. In addition, we evaluated the uptake characteristics for the three dominant amino acid neurotransmitters, glutamate, GABA, and glycine. Whereas, cellular localisation of all amino acids was similar to control retinas, there were major changes in the level of immunoreactivity, even before eye opening, and well before the onset of visibly detectable photoreceptor degeneration. Two major patterns emerged. First, neurochemical changes evident before degeneration, involving the amino acids glutamate, GABA, aspartate, glutamine, and arginine. Second, neurochemical changes that become evident during photoreceptor degeneration involving the amino acids taurine and glycine. Anomalies in uptake characteristics also become evident during the degeneration phase and are likely to reflect changes in cellular function as a consequence of the degeneration process. Neurochemical changes evident before photoreceptor degeneration involve both glutamate and GABA manufacturing pathways. Müller's cells displayed elevated levels of glutamine and arginine from an early age, and the neuroblastic layer in the RCS retina showed high glutamate levels. Modified aspartate immunoreactivity began at postnatal day 11 and is consistent with altered metabolic activity. These results suggest that amino acid neurochemistry is different in the RCS rat retina from an early age, which may indicate an underlying metabolic defect affecting multiple cell classes.

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Section: Localisation Of the Amino Acid Neurotransmitters And Substansupporting

confidence: 78%

Section: Localisation Of the Amino Acid Neurotransmitters And Substansupporting

confidence: 55%

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Neurochemical development of the degenerating rat retina

Fletcher

Kalloniatis

1997

J. Comp. Neurol.

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“…6a; Mosinger et al, 1986;VersauxBotteri et al, 1989;Lake, 1994). Within the inner nuclear layer, amacrine cells were the predominant cell type that was immunoreactive for GABA.…”

Section: Glutaminementioning

confidence: 99%

Neurochemical architecture of the normal and degenerating rat retina

Fletcher

Kalloniatis

1996

J. Comp. Neurol.

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We used post-embedding immunocytochemistry to determine the cellular localization of glutamate, gamma-amino butyric acid (GABA), glycine, aspartate, glutamine, arginine, and taurine in the normal and degenerating rat retina. Müller's cell function was also evaluated by determining the uptake and degradation characteristics for glutamate. Immunocytochemical localization of amino acids in adult Royal College of Surgeons (RCS) and control rat retinas were similar with respect to cell classes. Differences in the intensity of labelling for glutamate, aspartate, glutamine, and glycine were observed in several classes of neurons, but the most prominent differences were shown by bipolar cells of the adult RCS rat retina. In addition, glutamine labelling within Müller's cells was higher in the RCS rat than the control. These changes may have occurred because of alterations in the glutamate production or degradation pathways. We tested this hypothesis by determining Müller's cells glutamate uptake and degradation characteristics in adult and postnatal day 16 RCS retinas. High affinity uptake of 3[H]-glutamate revealed an accumulation of grains over Müller's cell bodies in the adult RCS retina implying glutamate degradation anomalies. We confirmed anomalies in glutamate metabolism in RCS Müller's cells by showing that exogenously applied glutamate was degraded over a longer time course in postnatal day 16 RCS retinas, compared to control retinas. Differences in arginine immunoreactivity in adult and immature RCS retinas conform to the presumed dysfunction of Müller's cells in these degenerating retinas. The anomalies of amino acid localization, uptake and degradation lead us to conclude that Müller's cells in the RCS retina show abnormal function by postnatal day 16; an earlier time to previously reported anatomical and functional changes in this animal model of retinal degeneration.

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“…Another molecule shown to increase the number of rods that differentiate in neonatal rat retinal cultures is taurine (Altshuler et al, 1993). Taurine is present in all cells of the developing retina at a high concentration and is known to be critical for rod survival in adult animals (Hayes et al, 1975;Lake, 1994). There is no direct evidence that taurine acts on the retinal progenitor cells to influence their decision to adopt a rod photoreceptor cell fate; rather, taurine is likely to be critical for the later stages of rod differentiation because it causes an increase in the number of opsin ϩ cells when added to cultures many days after cells have undergone their final mitotic division (Altshuler et al, 1993).…”

Section: Hedgehog Proteins Promote Photoreceptor Differentiation In Vmentioning

confidence: 99%

Sonic Hedgehog Promotes Rod Photoreceptor Differentiation in Mammalian Retinal CellsIn Vitro

et al. 1997

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The hedgehog gene family encodes secreted proteins important in many developmental patterning events in both vertebrates and invertebrates. In the Drosophila eye disk, hedgehog controls the progression of photoreceptor differentiation in the morphogenetic furrow. To investigate whether hedgehog proteins are also involved in the development of the vertebrate retina at stages of photoreceptor differentiation, we analyzed expression of the three known vertebrate hedgehog genes. We found that Sonic hedgehog and Desert hedgehog are expressed in the developing retina, albeit at very low levels, whereas Indian hedgehog (Ihh) is expressed in the developing and mature retinal pigmented epithelium, beginning at embryonic day 13. To determine whether hedgehog proteins have activities on developing retinal cells, we used an in vitro system in which much of retinal histogenesis is recapitulated. N-terminal recombinant Sonic Hedgehog protein (SHH-N) was added to rat retinal cultures for 3-12 d, and the numbers of retinal cells of various phenotypes were analyzed by immunohistochemistry. We found that SHH-N caused a transient increase in the number of retinal progenitor cells, and a 2-to 10-fold increase in the number of photoreceptors differentiating in the cultures when analyzed with three different photoreceptor-specific antigens. In contrast, the numbers of retinal ganglion cells and amacrine cells were similar to those in control cultures. These results show that Hedgehog proteins can regulate mitogenesis and photoreceptor differentiation in the vertebrate retina, and Ihh is a candidate factor from the pigmented epithelium to promote retinal progenitor proliferation and photoreceptor differentiation.

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Taurine and GABA in the rat retina during postnatal development

Cited by 46 publications

References 22 publications

Neurochemical development of the degenerating rat retina

Neurochemical development of the degenerating rat retina

Neurochemical architecture of the normal and degenerating rat retina

Sonic Hedgehog Promotes Rod Photoreceptor Differentiation in Mammalian Retinal CellsIn Vitro

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