We have another beautiful image (larger size image here) from Gabe Luna in Steve Fisher’s and Geoff Lewis‘ group. This image representing the evolution of disease post retinal detachment, earned Honorable Mention in the 2013 Olympus Bioscapes International Digital Imaging Competition.
The image is a 60x image using laser scanning confocal image of the murine retinal nerve fiber layer after 2 weeks after retinal detachment. The ganglion cell axons (red), astrocytes (green), and blood vessels (blue) are labeled using SMI-32, GFAP, and Collagen IV antibodies respectively.
This abstract was presented today at the Association for Research in Vision and Opthalmology (ARVO) meetings in Seattle, Washington by Robert E. Marc, Felix R. Vazquez-Chona, John V. Hoang, Crystal Sigulinsky, Carl B. Watt, Bryan W. Jones, James R. Anderson and J. Scott Lauritzen. Continue reading “Pure Feedforward Amacrine Cells”
This paper in the Journal of Comparative Neurology by J. Scott Lauritzen, James R. Anderson, Bryan W. Jones, Carl B. Watt, Shoeb Mohammed, John V. Hoang and Robert E. Marc is another effort out of the Marc Laboratory For Connectomics that continues to define complete neural circuits to completeness.
This paper is another elucidation of data from the first Rabbit Retinal Connectome volume (RC1) that reveals that the division between the ON and the OFF inner plexiform layer (IPL) is not structurally absolute. ON cone bipolar cells make noncanonical axonal synapses onto specific targets and receive amacrine cell synapses in the nominal OFF layer, creating novel motifs, including inhibitory crossover networks. Automated transmission electron microscopic imaging, molecular tagging, tracing, and rendering of ∼400 bipolar cells reveals axonal ribbons in 36% of ON cone bipolar cells, throughout the OFF IPL. The targets include γ-aminobutyrate (GABA)-positive amacrine cells (γACs), glycine-positive amacrine cells (GACs), and ganglion cells. Most ON cone bipolar cell axonal contacts target GACs driven by OFF cone bipolar cells, forming new architectures for generating ON–OFF amacrine cells. Many of these ON–OFF GACs target ON cone bipolar cell axons, ON γACs, and/or ON–OFF ganglion cells, representing widespread mechanisms for OFF to ON crossover inhibition. Other targets include OFF γACs presynaptic to OFF bipolar cells, forming γAC-mediated crossover motifs. ON cone bipolar cell axonal ribbons drive bistratified ON–OFF ganglion cells in the OFF layer and provide ON drive to polarity-appropriate targets such as bistratified diving ganglion cells (bsdGCs). The targeting precision of ON cone bipolar cell axonal synapses shows that this drive incidence is necessarily a joint distribution of cone bipolar cell axonal frequency and target cell trajectories through a given volume of the OFF layer. Such joint distribution sampling is likely common when targets are sparser than sources and when sources are coupled, as are ON cone bipolar cells.
Figure Above: The first Rabbit Retinal Connectome volume (RC1), constructed via automated transmission electron microscopy (ATEM) and computational molecular phenotyping (CMP), spans the mid-inner nuclear layer (INL) at section 001 to the ganglion cell layer (GCL) at section 371, shown in a mirror image below. RC1 is a short cylinder ≈ 250 μm in diameter and ≈ 30 μm high containing 341 ATEM sections and 11 intercalated CMP sections. The cylinder is capped at top and bottom with 10-section CMP series allowing molecular segmentation of cells, and an activity marker, 1-amino-4-guanidobutane (AGB), to mark cells differentially stimulated via glutamatergic synapses. ATEM section 001 is a horizontal plane section through the INL visualized with GABA.glycine.glutamate → red.green.blue transparency mapping and a dark gold alpha channel (ANDed taurine + glutamine channels). ATEM section 371 is a horizontal plane section through the GCL visualized with GABA.AGB.glutamate → red.green.blue transparency mapping.
This paper by Q. He, Wang P and Ning Tian characterizes the developmental profiles of the light evoked excitatory and inhibitory synaptic inputs from ON and OFF synaptic pathways in the retina, the light evoked synaptic outputs and the sensitivity of the light evoked synaptic inputs and outputs to light deprivation of retinal ganglion cells (RGCs) and displaced amacrine cells (ACs) of developing mouse retina. The results strongly suggest that spontaneous and light-evoked synaptic activities of RGCs and ACs are regulated by different synaptic mechanisms.
Continue reading “Light-Evoked Synaptic Activity of Retinal Ganglion and Amacrine Cells is Regulated in Developing Mouse Retina”
This is the second paper in the category, 100 Papers You Should Read (in vision science).
Continue reading “100 Papers You Should Read, Functional Organization of Catfish Retina”