Developmental immunoreactivity for GABA and GAD in the avian retina: possible alternative pathway for GABA synthesis

Hokoç, Jan H.; Ventura, Ana Lúcia Marques; Gardino, P.F.; Mello, Fernando G. de

doi:10.1016/0006-8993(90)91760-e

Cited by 65 publications

(32 citation statements)

References 31 publications

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“…Liu et al found that in the E16.5-E18.5 mouse retina some Lim1+ cells could be found outside their proper lamina (Liu et al, 2000). In two reports on GABA expression during development in the chick and human embryo, 'ectopic' expression was found at time points that corresponds to our current observations (Hokoc et al, 1990;Nag and Wadhwa, 1997). Furthermore, a previous observation in our laboratory, which prompted us to undertake this study, showed how the pattern for nerve growth factor expression changed from being located vitreally at E5.5-E6 (st27-29) to be expressed in the external inner nuclear layer later (Karlsson et al, 2001).…”

Section: Discussionsupporting

confidence: 88%

Newborn horizontal cells migrate bi-directionally across the neuroepithelium during retinal development

Edqvist

Hallböök

2004

Development

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Cell migration plays an important role during the development of the retina. In this work we have studied the migration of newborn horizontal cells in avian embryonic retina. Using the pattern of the early expressed transcription factors Lim1 and Prox1 we have shown that horizontal cells migrate bi-directionally from their site of birth, close to the ventricular side, to the adjacent (vitreal) side of the neuroepithelium, where they align just next to the prospective ganglion cell layer before migrating back again to their final laminar position in the external part of the inner nuclear layer. The migration occurs between Hamburger and Hamilton stages 24 and 33,which is equivalent to embryonic day 4.5 and 8. Between stages 26 and 30 the horizontal cells reside close to the ganglion cell layer and intra ocular injections of a cytochalasin D, an actin polymerisation blocker that inhibit migration, at stage 29 interfered with the migration of the horizontal cells to their final destination. Furthermore, using biolistic gene transfer with a green fluorescence protein expression vector of retinal slices we were able to record ventricle-directed migration by time-lapse microscopy. Combining biolistics with immunohistochemistry we showed that transfected cells, which have also been translocated in a ventricular direction were positive for the horizontal cell markers Lim1 and Prox1. The alternative path of migration that is described in this work differs from the generally accepted one for horizontal cells and this knowledge will influence the view of how the molecular determination of horizontal cells is specified.

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Section: Discussionsupporting

confidence: 88%

Newborn horizontal cells migrate bi-directionally across the neuroepithelium during retinal development

Edqvist

Hallböök

2004

Development

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“…Antibody to ChAT did not label retinal cells at earlier stages (not shown), and IPL cells at E7.5-8 were the only ChAT-immunoreactive cell types seen, as described by Spira and co-workers (1987). However, antibody to GABA also labeled scattered cells at various positions between the ventricular surface and the developing IPL between E6 and E7.5 (not shown), in agreement with a report by Hokoç et al (1990).…”

Section: Co-localization Of Gaba and Chat In Neuroblasts Of Types I Asupporting

confidence: 92%

“…At E8-9, choline acetyltransferase (ChAT)-like immunoreactivity is present in two rows of cells, one in the inner margin of the INL and the other inside the IPL, which are already identified as Types I and II cholinergic amacrine cells (Type III cholinergic amacrine cells appear 3 days before hatching). GABA-like immunoreactivity is found in the developing chick retina in migrating neuroblasts in the INL, in both conventional and displaced amacrine cells, and also in horizontal cells (Hokoç et al, 1990).…”

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confidence: 99%

Spatiotemporal gradients of differentiation of chick retina types I and II cholinergic cells: Identification of a common postmitotic cell population

et al. 1999

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“…It could be suggested from our study that GABA might act as a trophic factor by activating L-type calcium channels during the 'early period of retinal neurogenesis. It is known that GABA and GA BAergic cells appear by E6 (De Mello et a]., 1976 Frederick, 1987;HokoC et al, 1990) before syn apse formation (E14, Sheffield and Fischman 1970) in the chick retina. GABA has been reportec to act as a trophic factor during neuronal development in various nervous systems.…”

Section: Functional Roles Of L-type Calcium Channels and Gaba During mentioning

confidence: 99%

Calcium channels and GABA receptors in the early embryonic chick retina

Yamashita

Fukuda

1993

J. Neurobiol.

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The properties of calcium channels were studied at the period of neurogenesis in the early embryonic chick retina. The whole neural retina was isolated from embryonic day 3 (E3) chick and loaded with a Ca(2+)-sensitive fluorescent dye (Fura-2). The retinal cells were depolarized by puff application of high-K+ solutions. Increases in intracellular Ca2+ concentrations were evoked by the depolarization through calcium channels. The type of calcium channel was identified as L-type by the sensitivity to dihydropyridines. The Ca2+ response was completely blocked by 10 microM nifedipine, whereas it was remarkably enhanced by 5 microM Bay K 8644. Then we sought a factor to activate the calcium channel and found that GABA could activate it by membrane depolarization at the E3 chick retina. Puff application of 100 microM GABA raised intracellular Ca2+ concentrations, and this Ca2+ response to GABA was also sensitive to the two dihydropyridines. Intracellular potential recordings verified clear depolarization by bath-applied 100 microM GABA. The Ca2+ response to GABA was mediated by GABAA receptors, since the GABA response was blocked by 10 microM bicuculline or 50 microM picrotoxin, and mimicked by muscimol but not by baclofen. Neither glutamate, kainate, nor glycine evoked any Ca2+ response. We conclude that L-type calcium channels and GABAA receptors are already expressed before differentiation of retinal cells and synapse formation in the chick retina. A possibility is proposed that GABA might act as a trophic factor by activating L-type calcium channels via GABAA receptors during the early period of retinal neurogenesis.

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Developmental immunoreactivity for GABA and GAD in the avian retina: possible alternative pathway for GABA synthesis

Cited by 65 publications

References 31 publications

Newborn horizontal cells migrate bi-directionally across the neuroepithelium during retinal development

Newborn horizontal cells migrate bi-directionally across the neuroepithelium during retinal development

Spatiotemporal gradients of differentiation of chick retina types I and II cholinergic cells: Identification of a common postmitotic cell population

Calcium channels and GABA receptors in the early embryonic chick retina

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