Immunohistochemical Localization of Phospholipase D1 in Developing Rat Forebrain / 대한해부학회지

ABSTRACT

Phospholipase D (PLD), one of the intracellular signal transduction enzymes, may play an important role in developing brain. However, the developmental regulation of PLD protein has not been determined. In the present study, we investigated the temporal and spatial expression of PLD isozyme, PLD1 in the developing rat forebrain using an affinity-purified peptide antibody against PLD1. Our data showed that immunoreactivity for PLD1 was first seen in the germinal zone of the lateral ventricle, differentiating neurons and their processes at embryonic day 18 (E18). At E20, clusters of immunoreactive cells were observed in the medial germinal zone of the lateral ventricle, restricted zones of the frontal and parietal cortex, the nuclei of the medial septum and the diagonal band. During the first postnatal week, there was an increase in the number and staining intensity of the immunoreactive neurons in the cerebral cortex, which peaked at postnatal day 7 (P7). During the second postnatal week, there was an abrupt decrease in the number of immunoreactive cortical pyramidal neurons. By P14, only a few of the pyramidal neurons in cerebral cortex layer V were immunoreactive. These results revealed that expression of PLD1 protein at various stages of development of the septum and cerebral cortex is differentially regulated. This suggests that PLD1 may regulate the developmental processes of some neuronal populations.