NeuroD2 controls inhibitory circuit formation in the molecular layer of the cerebellum.

The cerebellar cortex is involved in the control of diverse motor and non-motor functions. Its principal circuit elements are the Purkinje cells that integrate incoming excitatory and local inhibitory inputs and provide the sole output of the cerebellar cortex. However, the transcriptional control of circuit assembly in the cerebellar cortex is not well understood.

Neuronal basic helix-loop-helix proteins Neurod2/6 regulate cortical commissure formation before midline interactions.

Establishment of long-range fiber tracts by neocortical projection neurons is fundamental for higher brain functions. The molecular control of axon tract formation, however, is still poorly understood. Here, we have identified basic helix-loop-helix (bHLH) transcription factors Neurod2 and Neurod6 as key regulators of fasciculation and targeted axogenesis in the mouse neocortex.

Identification of Gas6, a putative ligand for Sky and Axl receptor tyrosine kinases, as a novel neurotrophic factor for hippocampal neurons.

Sky (also known as "Tyro3" and "Rse") is a member of the Axl/Sky/Mer receptor tyrosine kinase family and has two immunoglobulin-like repeats and two fibronectin type III-like repeats in the extracellular domain. Gas6 is a ligand for all members of the Axl family, each of which (Axl, Sky, and c-Mer) has different affinities to Gas6. Physiological functions of Sky and Gas6 in the nervous system are not well understood, despite their importance, which is suggested by Sky structural features and its predominant expression in the brain.

Proximal promoter region is sufficient to regulate tissue-specific expression of UDP-galactose: ceramide galactosyltransferase gene.

UDP-galactose:ceramide galactosyltransferase (CGT) is the enzyme which catalyzes the final step of the biosynthesis of galactocerebroside (GalC), the most abundant glycolipid in myelin. We identified regulatory elements which are related to the tissue-specific expression of the mouse CGT gene by promoter assay using chimeric CGT-luciferase constructs. By comparing promoter activity in oligodendroglial CG4 cells and NIH3T3 fibroblasts, only a few hundred base pairs spanning from -309 to -98 were shown to be necessary for the tissue-specific activity of CGT promoter.