Animals use spatial differences in environmental light levels for visual navigation; however, how light inputs are translated into coordinated motor outputs remains poorly understood. Here we reconstruct the neuronal connectome of a four-eye visual circuit in the larva of the annelid Platynereis using serial-section transmission electron microscopy. In this 71-neuron circuit, photoreceptors con...

The avian trigeminal ganglion, which is embryonically derived from the neural crest and epidermal placodes, consists of two topographically segregated classes of immature neurons, large and small, during the second week of incubation, and two neuronal cell types, dark and light, interspersed throughout the mature ganglion. In order to establish the times of terminal mitosis of trigeminal sensor...

Living chick embryo spinal ganglion neurons grown from 1 to 4 weeks in vitro were studied under the phase contrast microscope. In the peripheral cytoplasm of the earliest stages studied, a homogeneous, phase-dense material is seen which corresponds in location to the cytoplasmic basophil material of the same stages. As maturation proceeds, this material increases in extent, and becomes separate...

Recent experiments indicate that the dark-adapted vertebrate visual system can count photons with a reliability limited by dark noise in the rod photoreceptors themselves. This suggests that subsequent layers of the retina, responsible for signal processing, add little if any excess noise and extract all the available information. Given the signal and noise characteristics of the photoreceptors...

Almost all organisms show some kind of time periodicity in their behavior. Especially in mammals the neurons of the suprachiasmatic nucleus form a biological clock regulating the activity-inactivity cycle of the animal. This clock is stimulated by the natural 24-hour light-dark cycle. In our model of this system we consider each neuron as a so called phase oscillator, coupled to other neurons f...

we investigate the growth of matter density perturbations as well as the generalized second law (gsl) of thermodynamics in the framework of f(r)-gravity. we consider a spatially flat frw universe filled with the pressureless matter and radiation which is enclosed by the dynamical apparent horizon with the hawking temperature. for some viable f(r) models containing the starobinsky, hu-sawicki, exp...

objective: patients with metabolic syndrome are prone to cardiovascular disease and diabetes. regarding the importance of nutritional factors in management of metabolic syndrome, this study was designed to evaluate the effects of dark chocolate consumption on serum lipid profile in patients with metabolic syndrome. materials and methods: in this randomized clinical trial, 114 patients with meta...

This study examined the expression of a neuron-specific cell adhesion molecule, OBCAM (opioid-binding cell adhesion molecule), at both the mRNA and protein levels in the cat primary visual cortex at various postnatal ages, using cDNA array analysis and immunocytochemistry. Results obtained using both methods showed that the expression level of OBCAM was high in young and low in older and adult ...