A new slicing method for the lower vertebrate brain: brain mould and adjustable stage

This paper describes a new method for slicing the lower vertebrate brain which is too small and soft to be sliced using conventional methods. The brain is sliced in a pre-prepared agar mould glued to a special stage placed in a conventional vibratome. The mould is constructed from a plaster model prepared by embedding a paraformaldehyde fixed brain in a paraffin and vaseline mixture. The brain to be sliced is placed within two prepared agar half cylinders which are in turn placed in a pre-prepared larger agar collar glued to a special stage. The study describes in detail the preparation of the interlocking collar and inner cylinders of agar. The plexiglass stage allows the agar block containing the brain, to be rotated and inclined to improve the angle of cut. By using this method, small and soft brain even with thin walls and large ventricles could be sliced coronally, sagittally, horizontally or obliquely. Brain slices obtained by this method have good viability showing spontaneous and evoked activity.