[Extrapapillary mechanoceptive afferent system of the frog tongue]

Tactile stimuli applied to the interpapillary spaces of the frog's tongue surface, activated mechanoreceptor afferences. The neurons of these afferences are associated only to the hypoglossal nerve and are able to make a complex central influence. A first effect is a hypo-hypoglossal reflex concerning the muscles of the tongue and of its floor. A second effect is a antidromic discharge of impulses travelling in the dorsal root of hypoglossal nerve and thus representing a DRR. Possibly this effect is related to the PAD phenomena of central terminals of the mechanoreceptors extrapapillary afferences.