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Vision: bringing the two sides together A protein regulating gene expression called Vax1 is essential for building the optic chiasm (OC), a brain structure where nerves from the left and right eyes cross to the other side of the brain. Signals from both eyes must be integrated for space and depth perception. Although some cues guiding optic nerve growth are known, those for the OC are not. Jin Woo Kim at the Korea Advanced Institute of Science and Technology, Daejeon, South Korea, and co-workers investigated visual development in mice expressing a mutant Vax1. They found that the mutant Vax1 could not support the optic nerve, which grew slowly and failed to connect to the other side of the brain. Consequently, the mice had impaired depth perception and low vision. These results show the importance of Vax1 for the development of binocular vision.

ß-Catenin (Ctnnb1) has been shown to play critical roles in the development and maintenance of epithelial cells, including the retinal pigment epithelium (RPE). Ctnnb1 is not only a component of intercellular junctions in the epithelium, it also functions as a transcriptional regulator in the Wnt signaling pathway. To identify which of its functional modalities is critically involved in mouse RPE development and maintenance, we varied Ctnnb1 gene content and activity in mouse RPE lineage cells and tested their impacts on mouse eye development. We found that a Ctnnb1 double mutant (Ctnnb1dm), which exhibits impaired transcriptional activity, could not replace Ctnnb1 in the RPE, whereas Ctnnb1Y654E, which has reduced affinity for the junctions, could do so. Expression of the constitutively active Ctnnb1ex3 mutant also suppressed the development of RPE, instead facilitating a ciliary cell fate. However, the post-mitotic or mature RPE was insensitive to the loss, inactivation, or constitutive activation of Ctnnb1. Collectively, our results suggest that Ctnnb1 should be maintained within an optimal range to specify RPE through transcriptional regulation of Wnt target genes in the optic neuroepithelium. [ABSTRACT FROM AUTHOR]

The article presents a case study of a 29-year-old woman who admitted to the psychiatry clinic at Soon- Chun-Hyang University hospital diagnosed with peripartum depression topics including treatment with electroconvulsive therapy (ECT); routine laboratory tests; and risks during ECT.