Electrical coupling via gap junctions is a common property of CNS neurons. In retinal photoreceptors, coupling plays important roles in noise filtering, intensity coding, and spatial processing. In many vertebrates, coupling is regulated during the course of light adaptation. To understand the mechanisms of this regulation, we studied photoreceptor gap junction proteins. We found that two conne...

Neurons acquire their distinct shapes after passing through many transitional stages in early development. To reveal the dynamics and spatiotemporal sequence of process formation in situ, the growth of neurons in the optic tectum of live zebrafish embryos (54 to > 100 h old) was monitored using time-lapse videorecordings. Neurons were labeled by injecting the fluorescent vital dye DiO into the ...

In this paper, by using the exponential convexity property of a barrier function, we propose an infeasible interior-point method for Cartesian P_*(k) horizontal linear complementarity problem over symmetric cones. The method uses Nesterov and Todd full steps, and we prove that the proposed algorithm is well define. The iteration bound coincides with the currently best iteration bound for the Ca...

The formation of a growth cone at the tip of a severed axon is a key step in its successful regeneration. This process involves major structural and functional alterations in the formerly differentiated axonal segment. Here we examined the hypothesis that the large, localized, and transient elevation in the free intracellular calcium concentration ([Ca2+]i) that follows axotomy provides a signa...

Previous evidence has shown that the number of L and M cones in retina varies significantly between subjects. However, it is not clear how the variation of L/M ratio changes the behavioral performance of the subject. A model of transformation of data from retina to visual cortex for evaluation of various L/M cones ratios is presented. While L/M cone ratios close to 1 brings the best performance...

A negative phototransduction feedback in rods and cones is critical for the timely termination of their light responses and for extending their function to a wide range of light intensities. The calcium feedback mechanisms that modulate phototransduction in rods have been studied extensively. However, the corresponding modulation mechanisms that enable cones to terminate rapidly their light res...

Introduction: Stumbling or falling is a major health problem among the elderly which accounts for their majority of physical injuries such as pelvic fractures, disability, loss of independency and even death. The goal of the study was comparison of the effect of aerobic and resistance exercise on static and dynamic balance in old men. Methods: A quasi-experimental study was conducted and t...

Using an atomic force microscope (AFM) at a controlled contact force, we report the electrical signal response of multi-walled carbon nanotubes (MWCNTs) disposed on a golden thin film. In this investigation, we highlight first the theoretical calculation of the contact resistance between two types of conductive tips (metal-coated and doped diamond-coated), individual MWCNTs and golden substrate...