Chemoattractant receptors and lymphocyte egress from extralymphoid tissue: changing requirements during the course of inflammation.

Memory/effector T cells traffic efficiently through extralymphoid tissues, entering from the blood and leaving via the afferent lymph. During inflammation, T cell traffic into the affected tissue dramatically increases; however, the dynamics and mechanisms of T cell exit from inflamed tissues are poorly characterized. In this study, we show, using both a mouse and a sheep model, that large numbers of lymphocytes leave the chronically inflamed skin.

Gamma motor neurons express distinct genetic markers at birth and require muscle spindle-derived GDNF for postnatal survival.

Background: Gamma motor neurons (gamma-MNs) selectively innervate muscle spindle intrafusal fibers and regulate their sensitivity to stretch. They constitute a distinct subpopulation that differs in morphology, physiology and connectivity from alpha-MNs, which innervate extrafusal muscle fibers and exert force. The mechanisms that control the differentiation of functionally distinct fusimotor neurons are unknown.

Synaptic pathology, altered gene expression, and degeneration in photoreceptors impacted by drusen.

Purpose: Drusen are risk factors for age-related macular degeneration and have been shown to negatively impact cells of the RPE and retina. In this study, the effects of drusen on the synaptic machinery of retinal photoreceptors are investigated.

Methods: Human donor eye tissue containing retina, RPE, and choroid was processed for confocal immunofluorescence microscopy, laser capture microdissection, and light and electron microscopy.

Drusen-associated degeneration in the retina.

Purpose: Drusen are variably sized extracellular deposits that form between the retinal pigmented epithelium (RPE) and Bruch's membrane. They are commonly found in aged eyes, however, numerous and/or confluent drusen are a significant risk factor for age-related macular degeneration. The purpose of this study was to investigate the impact of drusen on overlying cells of the retina.