Taste comes in on three cranial nerves: the facial (front two-thirds of the tongue), glossopharyngeal (back third) and vagus (back of the mouth, epiglottis). They end in the solitary nucleus of the medulla, which relays to the ventral posterior nucleus of the thalamus and on to the gustatory cortex in the insula and frontal operculum. [1][2][3]
A tract has no shape of its own in this atlas; lit: the parts it runs through, in order.
The 3D brain needs JavaScript. The steps below still say where the taste pathway runs, in order.
The brain starts seen from the left, a little from below and the front, so the brainstem, the thalamus inside and the inferior frontal gyrus over the insula all show. Step through lights one step at a time, about 1.2 s each, bottom to top; tap a step below to light it. The lit step is in the bright highlight colour, the steps before it stay lit in a paler tint of it and the steps still ahead are grey. Drag to turn, pinch or scroll to zoom. Step through is off because your device asks for reduced motion; tap each step instead.
The atlas has no shape for the solitary nucleus, the ventral posterior nucleus, the gustatory cortex or the three nerves, so each step lights the part that holds it: the whole medulla, the whole thalamus, and the whole insula and inferior frontal gyrus, though the primary taste cortex covers only the front of the insula and the frontal operculum beside it. [4][3]
The route, in 3 steps
The taste fibres of the facial, glossopharyngeal and vagus nerves enter the brainstem and end in the rostral (upper) gustatory part of the solitary nucleus, a column of grey matter in the medulla oblongata; its caudal part takes signals from the heart, lungs and gut instead. Not a separate shape in this atlas; lit: the part that holds it, the medulla oblongata. [5][2]Where is the medulla oblongata?
Axons from the gustatory part of the solitary nucleus climb to the thalamus and end in the medial part of the ventral posterior medial nucleus (VPM), the nucleus that also relays touch from the face. Not a separate shape in this atlas; lit: the part that holds it, the thalamus. [3][5][6]Where is the thalamus?
From the thalamus taste reaches the primary gustatory cortex: the anterior insula and the frontal operculum on the inferior frontal gyrus (together the AI/FO), where taste is consciously perceived. The area has no separate shape in this atlas; lit: the insula and inferior frontal gyrus that hold it. [3][2]Where is the insula?Where is the inferior frontal gyrus?
More about the taste pathway
Other names: gustatory pathway, central gustatory pathway [3][2]
Which nerve carries what: the facial nerve, through its chorda tympani branch, brings taste from the front two-thirds of the tongue; the glossopharyngeal nerve from the back third; and a branch of the vagus nerve from the back of the mouth and the epiglottis. [1][3]
Unlike smell, taste does relay in the thalamus: the solitary nucleus projects to the ventral posterior nucleus, and only then does the signal reach the gustatory cortex. [2]
From the primary gustatory cortex, taste is passed on to the orbitofrontal cortex, the secondary gustatory cortex, where it meets smell. [3]
Facts describe anatomy and normal function only. The 3D model is the adult male BodyParts3D brain (credits and licence); it has no shape for tracts, so a pathway is shown by the parts it runs through.