Immunohistochemical localization of GABA in chameleon retina (Chamaleo Chamaleo).

We used a policlonal antiserum against GABA and demonstrated GABA-immunoreactivity (GABA-IR) in several populations of amacrine cells in the inner nuclear layer (INL), and other cells in the inner plexiform layer (IPL) of the central and peripheral retina of the chameleon. Horizontal cells do not contain GABA-IR and the chameleon retina is therefore an exception among non-mammals. GABA-IR was not seen in cell bodies in the position of photoreceptor, bipolar and interplexiform cells suggesting that GABA is not involved in synaptic transmission in the outer plexiform layer of chameleon retina.

DNA synthesis in the embryonic chick lens epithelium is arrested after experimental lens rotation.

Using autoradiographic technique, we have studied DNA synthesis in normal embryonic chick lens epithelium and after experimental lens rotation. Analysis of the autoradiograms clearly demonstrates that when the lens primordium was rotated 180 degrees, so that lens epithelium was placed facing the interior of the optic cup, the lens epithelial cells completely stop DNA synthesis. This fact suggests that some retinal and vitreal factors are responsible for differentiation and replicative capacity of the lens epithelial cells.

Late events in the migrative behaviour of the retinal ganglion cells. A Golgi study in the chick retina.

The final displacement of the prospective ganglion neurons toward the ganglion cell layer (GCL) has been analyzed in chicken embryos during days 8 and 9 of incubation with the help of the Golgi method and computer-assisted image processing. Our findings indicate that some ganglionar soma are still located in the inner nuclear layer (INL) while others pierce the inner plexiform layer (IPL), exhibiting morphological adaptation of their perikaryon. The changing morphology of these delayed retinal ganglion neuroblasts seems to be due to the late translocation of the cell perikaryon to the GCL.

Development of retinal displaced ganglion cells in the chick: neurogenesis and morphogenesis.

The time of birth of displaced ganglion cells (DGCs) was determined by autoradiography. DGCs start to leave the cell cycle early, on embryonic day 3, in the central and peripheral retina, and end on embryonic day 8, also in both areas of the retina. During the period of neurogenesis, unlabeled (born) DGCs do not appear distributed in spatial gradients as do the ganglion, amacrine, and other cell types in the retina (Prada et al.

Effect of ethanol on the morphohistogenesis and differentiation of cerebellar granule cells in the chick embryo.

In this present study we analyse, with the help of the Golgi method, the effect of ethanol on the morphological differentiation of the cerebellar granule cells in the chick embryo. Ethanol seems to affect the process of cell migration from the early stages of differentiation. Some granule cells appear to differentiate in an inverted position.