ORGANOTYPIC SLICE CULTURE OF THE SUPRACHIASMATIC NUCLEUS

To establish an in vitro system which would enable us to observe SCN f unctions over a long period, we developed a new method to culture SCN tissues by means of a roller tube. Coronal slices containing the SCN w ere prepared from 5- to 7-day-old rat brains. Slices were maintained f or several weeks in plasma clots on coverslips that were immersed in a culture medium within a rotating test tube. in this preparation, vaso pressin- and vasoactive intestinal polypeptide-immunoreactive or their mRNA expressing neurons were found in the subdivisions, similar to th ose found in the SCN in vivo. Moreover, amounts of vasopressin release d from the SCN culture into the medium revealed circadian oscillation during the 48-h sampling period. Therefore, SCN in these slice culture conditions in vitro is able to maintain for several weeks not only to pographical organization but also functional integrity as a circadian pacemaker.