Noxious stimulation induces c-fos-like protein within neurons of the spinal cord and thalamus in patterns that suggest c-fos induction may serve as a marker for activity within nociresponsive pathways. Similar patterns of immunoreactivity were not seen following gentle mechanical stimulation or in control animals. Within the thalamus, noxious stimulation induces immunoreactivity not only in traditionally expected locations, but also within the paraventricular, submedial and reuniens nuclei.