Nociceptive input to ascending tract neurones forwarding information from low threshold cutaneous and muscle afferents in cats.

Effects of noxious skin stimulation (central foot pad and foot dorsum) by radiant heat were tested on neurones of ascending tracts with a main input from non-nociceptors. The dominating effect on ventral spinocerebellar tract neurones was a depression (mainly from the pad). Responses of spinocervical tract neurones were either facilitated (predominantly from the foot dorsum) or depressed (predominantly from the pad). The dominating effect on neurones tentatively classified as dorsal horn dorsal spinocerebellar tract neurones was facilitatory from both skin areas. Similar effects were evoked by selective actions of C-fibres when A-delta fibres were blocked by TTX.