Intracellular marking of identified neurones in the superficial dorsal horn of the cat spinal cord.

Intracellular iontophoresis of horseradish peroxidase has been used to mark identified neurones in the superficial dorsal horn of cats. The cats were anaesthetized with alpha-chloralose and paralysed with gallamine triethodide. Four specific nocireceptive neurones in the marginal zone and seven neurones in the substantia gelatinosa were recovered. One of the former and four of the latter are described in detail and are illustrated as reconstructions from serial sections. The results confirm previous conclusions that the substantia gelatinosa contains neurones classified as 'inverse' and that the nocireceptive neurones of lamina I are Waldeyer Cells.