Dispersion of the neurons expressing layer specific markers in the reeler brain.

Neurons with similar functions including neuronal connectivity and gene expression form discrete condensed structures within the vertebrate brain. This is exemplified within the circuitry formed by the cortical layers and the neuronal nuclei. It is well known that the Reelin protein is required for development of these neuronal structures in rodents and human, but the function of Reelin remains controversial.

Anterograde labeling of the corticospinal tract in jimpy mutant mice by Di I injection into the motor cortex.

Carbocyanine fluorescent dye, DiI, is an excellent anterograde/retrograde neural tracer, but its efficacy for the anterograde labeling of neural circuits in the adult brain tends to decrease with ages. The present study shows that an injection of DiI into the motor cortex of the young adult jimpy mutant mice (Plp1(jp)/+) resulted in successful anterograde labeling of corticospinal tract fibers. Furthermore, an injection of Fast Blue into the lumbar spinal cord of the mutant mice resulted in retrograde labeling of layer 5 corticospinal tract neurons within the motor cortex.

Expression of zebrafish ROR alpha gene in cerebellar-like structures.

Mouse genetic studies have identified several genes involved in cerebellar development. The mouse mutants staggerer and lurcher are functionally deficient for the retinoid-related orphan receptor alpha (ROR alpha) and glutamate receptor delta2 (Grid2) genes, respectively, and they show similar functional and developmental abnormalities in the cerebellum. Here, we report the cloning and expression pattern of zebrafish ROR alpha orthologues rora1 and rora2, and compare their expression pattern with that of grid2.

A mouse homologue of Strawberry Notch is transcriptionally regulated by Reelin signal.

Reelin is a glycoprotein secreted by specific neuronal populations of the adult and developing nervous system of vertebrates. The morphological abnormalities in the brain of reeler, the Reelin deficient mutant mice, indicate that Reelin is essential for the brain morphogenesis. However, biochemical function of Reelin signal is not well understood.