Regional variation in the organization and connectivity of the first synapse in the primate night vision pathway.

PubMed ID: 37915604

Author(s): Saha A, Zuniga J, Mian K, Zhai H, Derr PJ, Hoon M, Sinha R. Regional variation in the organization and connectivity of the first synapse in the primate night vision pathway. iScience. 2023 Oct 2;26(11):108113. doi: 10.1016/j.isci.2023.108113. eCollection 2023 Nov 17. PMID 37915604

Journal: I Science, Volume 26, Issue 11, Nov 2023

Sensitivity of primate daylight vision varies across the visual field. This is attributed to regional variations in cone photoreceptor density and synaptic connectivity of the underlying circuitry. In contrast, we have limited understanding of how synapse organization of the primate night vision pathway changes across space. Using serial electron microscopy, we reconstructed the first synapse of the night vision pathway between rod photoreceptors and second-order neurons, at multiple locations from the central part of the primate retina, fovea, to the periphery. We find that most facets of the rod synapse connectivity vary across retinal regions. However, rod synaptic divergence and convergence patterns do not change in the same manner across locations. Moreover, patterns of rod synapse organization are tightly correlated with photoreceptor density. Such regional heterogeneities revise the connectivity diagram of the primate rod synapse which will shape synapse function and sensitivity of the night vision pathway across visual space.