Carl B. Watt

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Mammalian retinal degenerations initiated by gene defects in rods, cones or the retinal pigmented epithelium (RPE) often trigger loss of the sensory retina, effectively leaving the neural retina deafferented. The neural retina responds to this challenge by remodeling, first by subtle changes in neuronal structure and later by large-scale reorganization.(More)
Many photoreceptor degenerations initially affect rods, secondarily leading to cone death. It has long been assumed that the surviving neural retina is largely resistant to this sensory deafferentation. New evidence from fast retinal degenerations reveals that subtle plasticities in neuronal form and connectivity emerge early in disease. By screening mature(More)
PURPOSE A connectome is a comprehensive description of synaptic connectivity for a neural domain. Our goal was to produce a connectome data set for the inner plexiform layer of the mammalian retina. This paper describes our first retinal connectome, validates the method, and provides key initial findings. METHODS We acquired and assembled a 16.5 terabyte(More)
Circuitry mapping of metazoan neural systems is difficult because canonical neural regions (regions containing one or more copies of all components) are large, regional borders are uncertain, neuronal diversity is high, and potential network topologies so numerous that only anatomical ground truth can resolve them. Complete mapping of a specific network(More)
Retinitis pigmentosa (RP) is an inherited blinding disease characterized by progressive loss of retinal photoreceptors. There are numerous rodent models of retinal degeneration, but most are poor platforms for interventions that will translate into clinical practice. The rabbit possesses a number of desirable qualities for a model of retinal disease(More)
Retinal guanylate cyclases 1 and 2 (GC1 and GC2) are responsible for synthesis of cyclic GMP in rods and cones, but their individual contributions to phototransduction are unknown. We report here that the deletion of both GC1 and GC2 rendered rod and cone photoreceptors nonfunctional and unstable. In the rod outer segments of GC double knock-out mice,(More)
Heterotrimeric kinesin-II is a molecular motor localized to the inner segment, connecting cilium and axoneme of mammalian photoreceptors. Our purpose was to identify the role of kinesin-II in anterograde intraflagellar transport by photoreceptor-specific deletions of kinesin family member 3A (KIF3A), its obligatory motor subunit. In cones lacking KIF3A,(More)
Retinal degenerative diseases that progress through loss of photoreceptors initiate a sequence of events that culminates in negative remodelling of the retina. Initially, photoreceptor loss ablates glutamatergic signalling to the neural retina and eliminates coordinate Ca++-coupled homeostatic signalling. Retinal neurons react to this loss of glutamatergic(More)
Orthograde axonal transport tracing methods were used to describe the projections to the basilar pontine nuclei (BPN) which arise within the face representation of motor or somatosensory cerebral cortex. Injections centered in motor face (MF) cortex resulted in the labeling of several corticopontine terminal fields which exhibit a rostrocaudal columnar(More)
Connectomics is a strategy for mapping complex neural networks based on high-speed automated electron optical imaging, computational assembly of neural data volumes, web-based navigational tools to explore 10(12)-10(15) byte (terabyte to petabyte) image volumes, and annotation and markup tools to convert images into rich networks with cellular metadata.(More)