Brn3a and Brn3b knockout mice display unvaried retinal fine structure despite major morphological and numerical alterations of ganglion cells. Issue 1 (29th July 2016)

• Record Type: Journal Article
• Authors: Ghinia, Miruna Georgiana; Novelli, Elena; Sajgo, Szilard; Badea, Tudor Constantin; Strettoi, Enrica
• Is Part Of: Journal of comparative neurology. Volume 527:Issue 1(2019)
• Page Start: 187
• Page End: 211
• Publication Date: 2016-07-29
• Subjects: Brn3 transcription factors -- ganglion cells -- inner plexiform layer -- mosaics -- synapses -- RRIDs: AB_94166 -- AB_2314052 -- AB_10000340 -- AB_2079751 -- AB_399431 -- AB_2533912 -- AB_2278725 -- AB_477035 -- AB_477345 -- AB_2492226 -- AB_390204 -- AB_10013783; Comparative neurobiology -- Periodicals; Neurology -- Periodicals; 616
• DOI: 10.1002/cne.24072
• Languages: English
• ISSNs: 0021-9967

Abstract

ABSTRACT: Ganglion cells (GCs), the retinal output neurons, receive synaptic inputs from bipolar and amacrine cells in the inner plexiform layer (IPL) and send information to the brain nuclei via the optic nerve. Although GCs constitute less than 1% of the total retinal cells, they occur in numerous types and are the first neurons formed during retinal development. Using Brn3a and Brn3b mutant mice in which the alkaline phosphatase gene was knocked‐in (Badea et al. [Neuron] 2009;61:852–864; Badea and Nathans [Vision Res] 2011;51:269–279), we studied the general effects after gene removal on the retinal neuropil together with the consequences of lack of development of large numbers of GCs onto the remaining retinal neurons of the same class. We analyzed the morphology, number, and general architecture of various neuronal types presynaptic to GCs, searching for changes secondary to the decrement in the number of their postsynaptic partners, as well as the morphology and distribution of retinal astrocytes, for their strong topographical relation to GCs. We found that, despite GC losses, retinal organization in Brn3 null mice is remarkably similar to that of wild‐type controls. J. Comp. Neurol. 527:187–211, 2019. © 2016 Wiley Periodicals, Inc. Abstract : The retina constitutes a highly organized, multilayered outpost of the CNS (left). Individual cell types commit to their fate and migrate to their final locations at different stages during development and within precise time frames. In this study we show that, even though ganglion cells are the first neurons to form and to assume their final location in the retina, a severe decrease in their number and major abnormalities in their dendritic arbors affect minimally the remaining retinal cells types, including their major synaptic partners (i.e., bipolar and amacrine cells) (right). Failure of proper ganglion cell development appears to have negligible consequences on overall retinal layering and synaptic architecture, suggesting that these retinal features follow intrinsic, hard‐wired rules.