A method for the collection of defined areas from the embryonic rat brain for cell and tissue culture

Tissue for the culture of cerebral neurons has frequently been taken from brains of the embryonic rats. In many cases it was impossible to obtain regularly and reproducibly small, defined pieces of tissue, e.g. diencephalic nuclei, of the extremely soft embryonic cerebral tissue. On the other hand, as a basis for tissue cultures, well defined samples are more and more considered essential. Therefore a method for collecting samples of defined small regions from the di- and mesencephalic rat brain, 17 days of gestation, was developed. It is applicable to cell and tissue culture. Embryonic brains are prepared aseptically and embedded in congealing Agarose. Stabilized in this gel they are cut into 225 micron slices using a tissue chopper. Tissue samples desired for culture are then punched out from the respective brain slice, which previously had been compared with corresponding reference micrographs. The correct localization of the tissue punch within the fresh brain slice is controlled histologically. The embedding procedure for performing the histology of the brain slices of 225 micron width is described. For application of the introduced method, coordinates for slicing and histological reference micrographs are given for di- and mesencephalic areas.