Increased density and age‐related sharing of synapses at the cone to OFF bipolar cell synapse in the mouse retina. Issue 7 (26th November 2019)

• Record Type: Journal Article
• Authors: Simmons, Aaron B.; Camerino, Michael J.; Clemons, Mellisa R.; Sukeena, Joshua M.; Bloomsburg, Samuel; Borghuis, Bart G.; Fuerst, Peter G.
• Is Part Of: Journal of comparative neurology. Volume 528:Issue 7(2020)
• Page Start: 1140
• Page End: 1156
• Publication Date: 2019-11-26
• Subjects: bipolar -- development -- plasticity -- refinement -- retina -- RRID: RRID:IMSR_JAX:002994 -- RRID: SCR_003070 -- RRID:AB_1163387 -- RRID:AB_2168560 -- RRID:AB_2307445 -- RRID:AB_2315178 -- RRID:AB_309969 -- RRID:AB_397957 -- RRID:AB_94671 -- RRID:IMSR_JAX:000659 -- RRID:IMSR_JAX:000664 -- RRID:IMSR_JAX:002448 -- RRID:IMSR_JAX:007909 -- RRID:MMRRC_010915‐UCD -- RRID:MMRRC_036750‐UCD -- RRID:SCR_010488 -- RRID:SCR_016566; Comparative neurobiology -- Periodicals; Neurology -- Periodicals; 616
• DOI: 10.1002/cne.24810
• Languages: English
• ISSNs: 0021-9967

Abstract

Abstract: Neural circuits in the adult nervous system are characterized by stable, cell type‐specific patterns of synaptic connectivity. In many parts of the nervous system these patterns are established during development through initial over‐innervation by multiple pre‐ or postsynaptic targets, followed by a process of refinement that takes place during development and is in many instances activity dependent. Here we report on an identified synapse in the mouse retina, the cone photoreceptor➔type 4 bipolar cell (BC4) synapse, and show that its development is distinctly different from the common motif of over‐innervation followed by refinement. Indeed, the majority of cones are contacted by single BC4 throughout development, but are contacted by multiple BC4s through ongoing dendritic elaboration between 1 and 6 months of age—well into maturity. We demonstrate that cell density drives contact patterns downstream of single cones in Bax null mice and may serve to maintain constancy in both the dendritic and axonal projective field. Abstract : Bipolar cell to cone contact patterns vary depending on genotype, density and age. (a and b) Cones are more likely to be contacted by multiple type 4 bipolar cells in the Bax −/− retina independent of BC4 density. (c and d) Cones are more likely to be sampled by multiple BC4s as the BC4 density increases. (e and f) BC4 number decreases between 5 and 12 weeks but cones are more likely to be sampled by multiple BC4s over the same time period.