scholarly journals The Lobster Optic Lamina

1966 ◽  
Vol 1 (2) ◽  
pp. 257-269
Author(s):  
J. HÁMORI ◽  
G. A. HORRIDGE
Keyword(s):  
Ganglion Cell ◽  
Synaptic Vesicles ◽  
Ganglion Cells ◽  
Postsynaptic Membrane ◽  
Retinula Cell ◽  
Secretory Vesicles ◽  
Presynaptic Membrane ◽  
Cell Axon ◽  
Sharp Distinction ◽  
Ganglion Cell Axon

The following interpretations are based on the assumption that the vesicles are presynaptic. Synapses between retinula cells are symmetrical contacts, with cisternae attached to both thickened membranes and the cleft is 8-10 mµ wide. Synapses from retinula terminal bags to the numerous invaginating spines of the ganglion cell axon have presynaptic ribbons and filaments but few vesicles; the cleft is 7.5-13 mµ wide. Synapses from retinula cell bags to secretory horizontal fibres have postsynaptic spines, typical vesicles one side and thickened presynaptic membrane (cleft Io-17 µ wide). Synapses from retinula fibres to empty (long) transverse fibres are similar. Synapses from secretory or empty transverse fibres to ganglion cell axons are axon-to-axon contacts; there are vesicles one side but both membranes are thickened; the cleft is 11-13 mµ wide. Between empty transverse fibres the synapses are similar but symmetrical; from empty to secretory transverse they have vesicles one side. Synapsesfrom secretory fibres to each other (symmetrical) or to empty transverse fibres (vesicles on one side and with only the postsynaptic membrane thickened) reveal a sharp distinction between synaptic vesicles and secretory vesicles. Serial synapses occur (a) from empty transverse fibre to secretory fibre to another empty transverse fibre, and (b) from retinula cell to secretory fibre to ganglion cell fibre. On account of its curious structure the optic cartridge probably has complex synaptic properties. Retinula terminals are probably inhibitory. Their light mitochondria, contrasting with the dense ones of the ganglion cells, are interpreted as aged.

scholarly journals EphA3 Expressed in the Chicken Tectum Stimulates Nasal Retinal Ganglion Cell Axon Growth and Is Required for Retinotectal Topographic Map Formation

PLoS ONE ◽  
2012 ◽  
Vol 7 (6) ◽  
pp. e38566 ◽  
Author(s):  
Ana Laura Ortalli ◽  
Luciano Fiore ◽  
Jennifer Di Napoli ◽  
Melina Rapacioli ◽  
Marcelo Salierno ◽  
...  
Keyword(s):  
Ganglion Cell ◽  
Retinal Ganglion Cell ◽  
Axon Growth ◽  
Retinal Ganglion ◽  
Topographic Map ◽  
Retinal Ganglion Cell Axon ◽  
Cell Axon ◽  
Ganglion Cell Axon

Brn3b/Brn3c double knockout mice reveal an unsuspected role for Brn3c in retinal ganglion cell axon outgrowth

Development ◽  
2002 ◽  
Vol 129 (2) ◽  
pp. 467-477 ◽  
Author(s):  
Steven W. Wang ◽  
Xiuqian Mu ◽  
William J. Bowers ◽  
Dong-Seob Kim ◽  
Daniel J. Plas ◽  
...  
Keyword(s):  
Cell Differentiation ◽  
Ganglion Cell ◽  
Retinal Ganglion Cells ◽  
Retinal Ganglion Cell ◽  
Knockout Mice ◽  
Ganglion Cells ◽  
Axon Outgrowth ◽  
Retinal Ganglion ◽  
Double Knockout ◽  
Ganglion Cell Axon

In mice, Brn3 POU domain transcription factors play essential roles in the differentiation and survival of projection neurons within the retina, inner ear, dorsal root and trigeminal ganglia. During retinal ganglion cell differentiation, Brn3b is expressed first, followed by Brn3a and Brn3c. Targeted deletion of Brn3b, but not Brn3a or Brn3c, leads to a loss of most retinal ganglion cells before birth. However, as a few retinal ganglion cells are still present in Brn3b–/– mice, Brn3a and Brn3c may partially compensate for the loss of Brn3b. To examine the role of Brn3c in retinal ganglion cell development, we generated Brn3b/Brn3c double knockout mice and analyzed their retinas and optic chiasms. Retinal ganglion cell axons from double knockout mice were more severely affected than were those from Brn3b-deficient mice, indicating that Brn3c was required for retinal ganglion cell differentiation and could partially compensate for the loss of Brn3b. Moreover, Brn3c had functions in retinal ganglion cell differentiation separate from those of Brn3b. Ipsilateral and misrouted projections at the optic chiasm were overproduced in Brn3b–/– mice but missing were entirely in optic chiasms of Brn3b/Brn3c double knockout mice, suggesting that Brn3c controlled ipsilateral axon production. Forced expression of Brn3c in Brn3b–/– retinal explants restored neurite outgrowth, demonstrating that Brn3c could promote axon outgrowth in the absence of Brn3b. Our results reveal a complex genetic relationship between Brn3b and Brn3c in regulating the retinal ganglion cell axon outgrowth.

Sign in / Sign up

Export Citation Format

Share Document