The developmental expression of voltage dependent calcium channel alpha1 subunits (alpha1D, alpha1B, alpha1A, alpha1E) mRNA in the rat brain / 대한해부학회지

ABSTRACT

Voltage dependent calcium channels (VDCCs) mediate Ca++ influx into cells and are responsible for regulation of a variety of physiological effects. The key functional property of VDCCs are attributed to the calcium-pore forming alpha1 subunit. In this study, distribution pattern of alpha1 subunit (alpha1D, alpha1B, alpha1A, alpha1E) mRNA of VDCCs in developing and adult rat brain was investigated by in situ hybridization histochemistry. In the adult rat brain, each alpha1 subunit mRNA displayed a specific and distinct distribution pattern. alpha1D was highly expressed in the olfactory bulb, dentate gyrus, pituitary gland, pineal gland, hypothalamus, superior colliculus and cerebellum. Relatively low level of alpha1B was expressed throughout the whole brain and strong expression of alpha1A was observed in CA3 area of Ammon's horn, medial geniculate body, inferior colliculus and cerebellum. High level of alpha1E was found in the olfactory bulb, hippocampus, dentate gyrus, medial habenular nucleus and cerebellum. Moreover, alpha1B, alpha1A and alpha1E were expressed only in the nervous system but alpha1D was expressed not only in the nervous system but also in other tissues including liver, heart, lung and skeletal muscle. Generally the expression of alpha1D, alpha1A, and alpha1E subunit was observed from E14 and thereafter the intensity of labeling was gradually increased to P14 and then decreased to the adult level. But the expression of alpha1B subunit was observed from E14 and gradually increased to E20 and P0 and then decresaed. From the differential expressions of VDCC alpha1 subunits in developing and adult rat brain, it is suggested that each type of VDCCs may play a distinct roles in neural and nonneural tissues, and the VDCCs may be related with development of nervous system.