Navigating growth cones need to integrate, process and respond to guidance signals, requiring dynamic information transfer within and between different compartments. Studies have shown that, faced with different navigation challenges, growth cones display dynamic changes in growth kinetics and morphologies. However, it remains unknown whether these are paralleled by differences in their interna...

The big eye kilka, Clupeonella grimmi, is a marine fish living in depth of 20 to 200 meter of the Caspian Sea. Its eye and retina were processed for histological and SEM studies. Paraffin embedded retina was cut radially and tangentially in 5 ?m thickness and stained with hematoxylin and eosin method. The unstained sections were manipulated for SEM image observations. Tangential retinal sect...

During axonogenesis, contacts made by the growth cone with its substratum are important in guiding the direction of neurone outgrowth. This study examines the contacts made by the growth cones of pioneer neurones in the embryonic grasshopper limb. Individual pioneer neurones at different stages of development were injected with horseradish peroxidase and the contacts made by the filopodia at th...

The aim of this study was to evaluate the effects of 6% sodium hypochlorite (NaOCl) on gutta-percha (GP) and Resilon cones. Six standardized GP and Resilon cones were selected and cut 3mm from their tip. One GP and 1 Resilon cone were used as control samples. Cones were immersed in 6% NaOCl for 1, 5, 10, 20, and 30 minutes, thoroughly rinsed with nanopure water, and dried with filter paper. The...

The morphology, fine structure and spectral sensitivity of retinal photoreceptors of two anchovy species were investigated using light and electron microscopy and microspectrophotometry. Distinct regional specialisation of cones was observed. Long and short (bilobed) cones were observed in the horizontal retinal belt, including the nasal and temporal retinal zones. Only triple cones with two lo...

We consider the problems of kinematic and dynamic constraints, with actuator saturation and wheel slippage avoidance, for motion planning of a holonomic three-wheeled omni-directional robot. That is, the motion planner must not demand more velocity and acceleration at each time instant than the robot can provide. A new coupled non-linear dynamics model is derived. The novel concepts of Velocity...

Coupling a single quantum emitter, such as a fluorescent molecule or a quantum dot (QD), to a plasmonic nanostructure is an important issue in nano-optics and nano-spectroscopy, relevant for a wide range of applications, including tip-enhanced near-field optical microscopy, plasmon enhanced molecular sensing and spectroscopy, and nanophotonic amplifiers or nanolasers, to mention only a few. Whi...

Growth cones, found at the tip of axonal projections, are the sensory and motile organelles of developing neurons that enable axon pathfinding and target recognition for precise wiring of the neural circuitry. To date, many families of conserved guidance molecules and their corresponding receptors have been identified that work in space and time to ensure billions of axons to reach their target...

During axonal pathfinding, the direction of nerve fiber extension is established by the growth cone, the motile structure at the distal tip of an elongating axon. It is the growth cone that navigates and directs axonal outgrowth by detecting and responding to complex molecular cues in the nervous system environment. Changes in growth cone behavior and morphology that result from contact with th...