A vibrating microtome attachment for cutting brain slice preparations at reproducible compound angles relative to the midline

Slice preparations isolate functional networks, permitting single unit recording under visual control, and the use of fluorescent indicators. Circuits of interest often lie at a tilt in both the rostrocaudal and ventrodorsal axis, thus exposing circuits of interest at the cut surface of a slice would require a device for tilting a preparation along two orthogonal axes relative to the blade. Such a device, designed to be used in conjunction with a vibrating microtome, permitting the isolation of slice preparations at reproducible angles, is described here. Because the two orthogonal axes of tilt can be independently and continuously adjusted, it is possible to use this device to successively refine tilt parameters from preparation to preparation for optimal exposure of circuits of interest, facilitating the development of new slice preparations. Its use in cutting a thick medullary slab preparation, isolated from the neonate rat, which exposes respiratory networks at the cut surface is described.