The projection of tooth pulp afferents in the spinal trigeminal nucleus (N.V.sp.) and the effect of dorsolateral medullotomy on cortical potentials evoked by electrical stimulation of Adelta tooth pulp nerve fibres were studied in cats. It was confirmed that antidromic responses were recorded in the tooth pulp nerve to stimulation of the ipsilateral but not the contralateral N.V.sp.[11]. Dorsolateral medullotomy at the level of the obex did not alter the cortical potentials induced by single pulses applied to the tooth pulp. It is concluded that Adelta tooth pulp afferents project exclusively to the ipsilateral trigeminal nucleus and that the impulse transmission to the cortex persists after transection of the pars caudalis of the N.V.sp.