Expression of a kinase anchoring protein 79 and synaptophysin in the developing human red nucleus

Our previous study showed that in the human fetal and neonatal brain, the magnocellular and parvocellular parts of the red nucleus can be well delineated by calcium-binding proteins. To study the development of rubral afferents, the expression of A kinase anchoring protein 79 (AKAP79) and synaptophysin (SYN) was examined in the human fetal red nucleus. It was found that during prenatal development both AKAP79 and SYN expression increased gradually although a major alteration in the distribution of the proteins within the two compartments of the red nucleus was not observed. In AKAP79 immunopreparations, the magnocellular part became well demarcated from 23 weeks of gestation onwards and both parts showed punctate immunolabelling with moderate to high packing densities of immunoreactive cells. SYN immunoreactivity with a punctate appearance was, however, mainly located in the parvocellular part. It was evenly distributed throughout the compartment at 14-22 weeks of gestation, and then from 23 weeks to the time of birth, there was a pericellular arrangement of SYN. Our observations are mainly in line with connectivity data regarding the red nucleus.