Nina's Journal

In the study "Ube3a is required for experience-dependent maturation of the neocortex" by Yashiro and colleagues, the authors examined how the neocortex (1) develops in Angelman syndrome model mice. These mice lack normal expression of the Ube3a (2) protein in the brain, which is the critical hallmark in all genetic forms of Angelman syndrome. The authors focused their studies on the visual cortex, as this region of the brain has a well-defined critical period during which visual experiences remodel the connections between neurons (3).

Read more: Experiences fail to guide brain maturation in Angelman syndrome model mice

This is a very important article as it indicates what according to specialists and researchers the diagnostic criteria for Angelman syndrome (AS) are. As such it is an important guide for clinicians who have to make (or exclude) an AS diagnosis.
This report is an update from the 1995 consensus statement. Nowadays, a genetic confirmation of the AS diagnosis is common in most Western-countries. However, it should be noted that in 10-15% of the individuals, the clinical diagnosis cannot be confirmed by current genetic tests.

Read more: Angelman syndrome 2005: Updated Consensus for Diagnostic Criteria

In this study, the authors investigated abnormalities in myelin (1) tissue (an electrically-insulating layer which forms a sheath around nerve fibers) in MRI (2) brain scans of 9 AS patients.

Read more: Abnormal myelination in Angelman syndrome

Just like the paper by Wu and colleagues earlier this year (1), this study describes the generation and phenotype (= appearance) of a fruit fly, which lacks the Ube3a gene (called Dube3a from Drosophila-Ube3a). Since lack of the Ube3a gene causes AS, this fly could be a good model for the disease.
This paper focuses on the way the neurons look (neuronal morphology) in the AS fly mutant.

Read more: Drosophila homologue of AS ubiquitin ligase regulates the formation of terminal dendritic branches