Intro | Facial Nerve | Glossopharyngeal Nerve | Gustatory Nucleus | Papilla | Primary Gustatory Cortex | Secondary Gustatory Cortex | Taste Buds | Tongue | Vagus Nerve | Ventral Posterior Nucleus
Part 1: Image-Mapped Tutorial
Part 2: Matching Self-Test
Part 3: Multiple-Choice Self-Test
The Primary Gustatory Cortex is located near the face area of the somatosensory cortex of the parietal lobe, which is located within the insular and opercular cortex of the frontal lobe. The precise contribution of the primary gustatory region to taste function is unclear. In a study of the responsiveness of single neurons within the primary gustatory cortex, little more than three percent of the neurons responded to taste quality. In the same study, somatosensory stimulation of the mouth and movements of the mouth were also associated with activation of neurons in the primary gustatory cortex. The distribution of taste sensitive neurons in the primary cortex bears no relationship to the distribution of these neurons at lower sites in the pathway (i.e., the gustatory nuclei of medulla and the ventral posterior thalamic nuclei). The primary gustatory cortex, however, may be organized in a columnar fashion as is typical of other cortical areas. Neurons of the primary gustatory cortex project to the secondary gustatory cortex.
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A very recent study of the altered taste perception of patients with damage to the primary gustatory cortex (rostrodorsal insula) indicates bilateral representation of taste perception bilaterally (Pritchard, Mascaluso & Eslinger, 1999). Specifically, the gustatory cortex of the right hemisphere may restrict its analysis of taste recognition and intensity to the ipsilateral tongue, whereas the gustatory cortex in the left hemisphere may process stimulus intensity ipsilaterally and taste recognition bilaterally. A very recent positron emission tomographic (PET) study of secondary gustatory cortex in humans has verified that parts of the peri-central opercular region (secondary somatosensory cortex) and insular cortex are important for gustatory processing (Frey & Petrides, 1999). In addition, functional magnetic resonance imaging (fMRI) has demonstrated that the brain regions involved in gustatory perception agree with the regions involved in the imagination of tastes (Levy, Henkin, Lin, Finley & Schellinger, 1999).
| References |
Frey, S. & Petrides, M. (1999). Re-examination of the human taste region: a positron emission tomography study. European Journal of Neuroscience 11(8), 2985-2988.
Levy, L.M., Henkin, R.I., Lin, C.S., Finley, A. & Schellinger, D. (1999). Taste memory induces brain activation as revealed by functional MRI. Journal of Computerized Assisted Tomography 23(4), 499-505.
Pritchard, T.C., Mascaluso, D.A. & Eslinger, P.J. Taste perception in patients with insular lesions. Behavioral Neuroscience, 113(4), 663-671.