Hippocampal slice preparation (A-F, left panel). A. Collect the brain after decapitation and separate the cerebellum with a scalpel blade following the dotted line. B. Separate the two hemispheres using a scalpel blade. C. Remove the midbrain to expose the hippocampus area. D. Remove the rostral part of the brain (containing the olfactory bulbs), in order to visualize the hippocampus (black arrow head). E. Put and orientate the dissected brain in the antero-posterior axis onto the slicing platform (2) of a tissue chopper (1) with perpendicular cut plan to the razor blade (3) and cut following dotted line. F. Dissociate and transfer slices to millicell insert culture systems relying on the OBC medium. Cerebellum slice preparation (A, B’-D’, F, right panel). A. Separate the cerebellum from the rest of the brain. B’. Remove the inferior colliculi (IC) and the brain stem (BS) from the cerebellum. C’. Put cerebellum on a Teflon plate according to the antero-posterior axis, and transfer to the slicing platform of the tissue chopper. D’. Cut sagittally following the dotted line. F. Transfer in a Petri dish containing dissection medium, dissociate carefully the slices from each other and plate them on the insert culture systems.