A novel spinal cord slice preparation from the rat.

A spinal cord slice preparation is described. The lumbar enlargement of weanling rats is exposed by laminectomy, the dorsal and ventral roots cut and a portion of cord consisting of about 4 segments removed and chilled to 3 degrees C. A modified tissue chopper is used to produce 400 micron dorsoventral longitudinal slices. The slices are maintained in a low-volume, continuously perfused tissue chamber at the interface between warm moist 95% O2/5% CO2 and oxygenated artificial cerebrospinal fluid, and remain viable for over 8 h. An extracellular recording of excitatory amino acid-induced activity of a dorsal horn lamina IV cell is shown. Excitatory amino acid antagonists applied iontophoretically and in the perfusate have actions similar to those in the adult spinal cord in vivo. This in vitro preparation of the cord has permitted stable extracellular recordings from single cells of 2 h or more, and has the potential for intracellular investigation of spinal cord neurones.