Abstract
In the mammalian retina, 10-12 different cone bipolar cell (BC) types decompose the photoreceptor signal into parallel channels, providing the basis for the functional diversity of retinal ganglion cells (RGCs). BCs differing in their temporal properties appear to project to different strata of the retina's inner synaptic layer, based on somatic recordings of BCs and excitatory synaptic currents measured in RGCs. However, postsynaptic currents in RGCs are influenced by dendritic morphology and receptor types, and the BC signal can be transformed at the axon terminals both through interactions with amacrine cells and through the generation of all-or-nothing spikes. Therefore, the temporal properties of the BC output have not been analyzed systematically across different types of mammalian BCs. We recorded calcium signals directly within axon terminals using two-photon imaging and show that BCs can be divided into ≥eight functional clusters. The temporal properties of the BC output were directly reflected in their anatomical organization within the retina's inner synaptic layer: faster cells stratified closer to the border between ON and OFF sublamina. Moreover, ≥three fastest groups generated clear all-or-nothing spikes. Therefore, the systematic projection pattern of BCs provides distinct temporal "building blocks" for the feature extracting circuits of the inner retina.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.