Claudin-3 in the non-neural ectoderm is essential for neural fold fusion in chicken embryos.

The neural tube, the embryonic precursor to the brain and spinal cord, begins as a flat sheet of epithelial cells, divided into non-neural and neural ectoderm. Proper neural tube closure requires that the edges of the neural ectoderm, the neural folds, to elevate upwards and fuse along the dorsal midline of the embryo. We have previously shown that members of the claudin protein family are required for the early phases of chick neural tube closure. Claudins are transmembrane proteins, localized in apical tight junctions within epithelial cells where they are essential for regulation of paracellular permeability, strongly involved in apical-basal polarity, cell-cell adhesion, and bridging the tight junction to cytoplasmic proteins. Here we explored the role of Claudin-3 (Cldn3), which is specifically expressed in the non-neural ectoderm. We discovered that depletion of Cldn3 causes folic acid-insensitive primarily spinal neural tube defects due to a failure in neural fold fusion. Apical cell surface morphology of Cldn3-depleted non-neural ectodermal cells exhibited increased membrane blebbing and smaller apical surfaces. Although apical-basal polarity was retained, we observed altered Par3 and Pals1 protein localization patterns within the apical domain of the non-neural ectodermal cells in Cldn3-depleted embryos. Furthermore, F-actin signal was reduced at apical junctions. Our data presents a model of spina bifida, and the role that Cldn3 is playing in regulating essential apical cell processes in the non-neural ectoderm required for neural fold fusion.

Educational Scholarship: A Modern Guide to Dissemination.

Dissemination of medical education scholarship is important for individual professional development and advancement of the field. With growing interest in medical education research, the venues for dissemination have grown in number and variety. In this article, we describe a general approach to meaningful dissemination of medical education scholarship, reviewing considerations for selection of a venue on the basis of type of project, personal and professional goals, and intended audience. After these overall principles, we provide an overview of specific venues, with equal emphasis on traditional manuscript-style submissions and newer digital opportunities for dissemination. Finally, we review tips for effective scholarly writing with a target venue in mind.