Design Principles of Insect and Vertebrate Visual Systems

Center for Brain Science, Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138, USA.
Neuron (Impact Factor: 15.05). 04/2010; 66(1):15-36. DOI: 10.1016/j.neuron.2010.01.018
Source: PubMed


A century ago, Cajal noted striking similarities between the neural circuits that underlie vision in vertebrates and flies. Over the past few decades, structural and functional studies have provided strong support for Cajal's view. In parallel, genetic studies have revealed some common molecular mechanisms controlling development of vertebrate and fly visual systems and suggested that they share a common evolutionary origin. Here, we review these shared features, focusing on the first several layers-retina, optic tectum (superior colliculus), and lateral geniculate nucleus in vertebrates; and retina, lamina, and medulla in fly. We argue that vertebrate and fly visual circuits utilize common design principles and that taking advantage of this phylogenetic conservation will speed progress in elucidating both functional strategies and developmental mechanisms, as has already occurred in other areas of neurobiology ranging from electrical signaling and synaptic plasticity to neurogenesis and axon guidance.

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    • "DSCAM and DSCAML.1) and extensive alternative splicing (Sanes and Zipursky, 2010). Based on these structural features, three members of the neural IgCAM family have been identified in C. intestinalis (Tassy et al., 2010). "
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    • "Instead, a particular lamina will contain axons and dendrites arising from specific neuronal subtypes resulting in the formation of laminae that contain synapses with the same or similar functional properties. For example, the retina and tectum/superior colliculus contain multiple synaptic laminae stacked on top of one another and a lamina's output will often represent one visual feature such as motion in a particular direction (Baier, 2013; Dhande and Huberman, 2014; Sanes and Zipursky, 2010). While there is now a wealth of experimental evidence showing that the generation of layers can be achieved through multiple cellular and molecular mechanisms (Sanes and Yamagata, 2009), the purpose of layers themselves is not known. "
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    • "Neurons activated by light decrements (OFF) stratify in the outer two sublaminae (S1-S2), whereas neurons activated by light increments (ON) stratify in the inner three (S3-S5). Cell-type-specific lamination patterns of neurites at precise depths of the IPL restrict potential connectivity and thus contribute to the synaptic specificity of retinal circuits (Sanes and Zipursky, 2010; Masland, 2012). "
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