The terminations of the spinothalamic tract in the cat

The termination sites of the spinothalamic tract (STT) in the cat have been examined using the anterograde transport of wheat germ agglutinin conjugated to horseradish peroxidase (WGA-HRP). Cats which received an injection of WGA-HRP at the spinal cervical level (C7-C8) displayed anterograde labelling in the ventral posterior lateral (VPL), ventrolateral, lateral posterior, limitans, suprageniculate, medial geniculate pars magnocellularis, central lateral, paracentral, centrum medianum, submedius, central medial, reuniens, rhomboid and periventricular thalamic nuclei. Lumbar injection (L2-L3) produced a similar although less intense pattern of labelling, with only the VPL displaying an obvious topological organization. Although the STT terminations in the cat appear to be less dense than those observed in the rat or monkey the present results demonstrate that in the cat a wide variety of thalamic nuclei receive a direct STT projection and that the cat VPL, like rat, monkey and man, receives a direct STT input.