As a further step to the evaluation of the functional significance of Staderini's nucleus intercalatus, the hypothesis has been tested that in the rabbit the functional level of this nucleus may change not only upon chemical activation of the lingual taste buds (papillae circumvallatae or foliatae), but also following stimulation of the roof nucleus and of cutaneous and mucous areas belonging to the V nerve. Unitary and multiunitary recordings from foci within Staderini's nucleus (extracellular tungsten microelectrodes, histologically controlled localizations) confirmed this hypothesis, which was suggested by hodological and functional considerations. The firing rate of a good proportion of the explored foci, in fact, was seen to increase or decrease following electrical or physiological stimulation of trigeminal peripheral fields, as well as electrical stimulation of the roof nucleus. In most cases, the same foci (or units) were also sensitive to the gustatory stimulation of the tongue. The reactive foci were not topographically organized within the nucleus. The results obtained are briefly discussed.