Spatial and temporal expression of UDP-galactose: ceramide galactosyl transferase mRNA during rat brain development.

We studied the expression of UDP-galactose: ceramide galactosyl transferase (CGT) mRNA in postnatal rat brains using an in situ hybridization technique. From P0 to P16, there was a defined temporal and spatial pattern to the earliest acquisition of CGT mRNA expression. In the forebrain, CGT mRNA-expressing (CGT+) cells were first detected in regions outside the subventricular zone around the lateral ventricle at P2. Cells in the external capsule, internal capsule and corpus callosum were later found to be CGT-positive. At P8 to P16, CGT+ cells were found in the thalamus, striatum, occipital and frontal cortex. In the case of midbrain and hindbrain, the first CGT+ signals were detected in the medullary raphe of the medulla oblongata at P0. CGT+ cells were subsequently located in the cerebellum, midbrain and pons from P4 to P16. That is, in regions closer to the areas in which CGT+ cells were first found, CGT mRNA expression was observed much earlier. These findings support the notion that there are at least two discrete waves of CGT mRNA signal expression in the forebrain and hindbrain.