Ultrastructure of the distal retina of the adult zebrafish, Danio rerio.

摘要: Abstract The organization, morphological characteristics, and synaptic structure of photoreceptors in the adult zebrafish retina were studied using light electron microscopy. Adult show a typical ordered tier arrangement with rods easily distinguished from cones based on outer segment (OS) morphology. Both contain mitochondria within inner segments (IS), including large, electron-dense megamitochondria previously described (Kim et al.) Four major ultrastructural differences observed between cones: (1) membranes cone lamellar disks showed wider variety relationships to plasma membrane than those rods, (2) pedicles typically had multiple ribbons, while rod spherules 1–2 (3) ribbons ∼2 times longer pedicles, (4) more cytoplasm pedicles. Examination photoreceptor terminals identified four at pedicles: invaginating contacts postsynaptic forming dyad, triad, quadrad synapses, presumed gap junctions connecting adjacent processes into terminals, basal away terminals. More vitread slightly farther removed extracellular microtubule-like structures association horizontal cell OPL. These findings, first document ultrastructure distal zebrafish, indicate that have many characteristics similar other species, further supporting use as model for vertebrate visual system.