We employ a number of statistical measures to characterize neural discharge activity in cat retinal ganglion cells (RGCs) and in their target lateral geniculate nucleus (LGN) neurons under various stimulus conditions, and we develop a new measure to examine correlations in fractal activity between spike-train pairs. In the absence of stimulation (i.e., in the dark), RGC and LGN discharges exhib...

BACKGROUND AND PURPOSE MR imaging has the potential capacity for noninvasively depicting the anatomy and function of thalamic nuclei. The purpose of this study was to identify the lateral geniculate nucleus (LGN), which is the thalamic relay nucleus for vision, with anatomic and functional MR imaging at 1.5 T. METHODS Three-millimeter-thick axial images were obtained from eight volunteers by ...

Although the lateral geniculate nucleus (LGN) is one of the most thoroughly characterized thalamic nuclei, its functional role remains controversial. Traditionally, the LGN in primates has been viewed as the lowest level of a set of feedforward parallel visual pathways to cortex. These feedforward pathways are pictured as connected hierarchies of areas designed to construct the visual image gra...

We introduce a new O(lg lgn)-competitive binary search tree data structure called poketree that has the advantage of attaining, under worst-case analysis, O(lg n) cost per operation, including updates. Previous O(lg lgn)-competitive binary search tree data structures have not achieved O(lg n) worst-case cost per operation. A standard data structure such as red-black tree or deterministic skip l...

Introduction In the mammalian visual system, light received by the eyes is transmitted through the optic nerves. Some of the nerve fibers go to the superior colliculus (SC), which mediates visual reflexes. The majority of other fibers go to the lateral geniculate nucleus (LGN) en route to the primary visual cortex (V1), which is responsible for visual perception[1]. The different parts of the v...

During development of the mammalian cerebral cortex, thalamic axons must grow into the telencephalon and select appropriate cortical targets. In order to begin to understand the cellular interactions that are important in cortical target selection by thalamic axons, we have examined the morphology of axons from the lateral geniculate nucleus (LGN) as they navigate their way to the primary visua...

Leaf architecture determines plant structural integrity, light harvesting, and economic considerations such as plant density. Ligules, junctions at the leaf sheath and blade in grasses, protect stalks from environmental stresses and, in conjunction with auricles, controls leaf angle. Previous studies in mutants have recessive liguleless mutants (lg1 and lg2) and dominant mutations in knotted1-l...