In this video, I discuss the sense of taste and follow the path of taste information from the tongue to the gustatory cortex.

TRANSCRIPT:

Welcome to 2 minute neuroscience, where I explain neuroscience topics in 2 minutes or less. In this installment I will discuss taste.

The tongue is covered with many little bumps, which are sometimes mistakenly called taste buds. These small lumps of tissue, however, are known as papillae.

Taste buds are found in the walls of papillae and the grooves surrounding them.

Each taste bud contains anywhere from 50 to 150 taste receptor cells. Extending from these cells are fine microvilli, sometimes called taste hairs or gustatory hairs, which protrude through an opening called the taste pore into the mouth. These microvilli come in contact with substances in the mouth that can be tasted, also known as tastants. Tastants interact with taste receptor cells through a number of different mechanisms to depolarize the cells.

When taste cells are depolarized, they release neurotransmitters that stimulate sensory neurons that travel in cranial nerves VII, IX, and X. These neurons terminate on neurons in the nucleus of the solitary tract in the medulla. From there, taste information is sent to the thalamus. Then, taste information is sent to the gustatory cortex, which is a region of the cerebral cortex found along the border between the anterior insula and a structure called the frontal operculum. The gustatory cortex allows us to consciously discriminate different taste stimuli. The taste information sent along these pathways is thought to encode for basic tastes, such as sweet, salty, sour, bitter, and savory or umami (whether there are others is still being debated). However, the actual flavor of a food---which is what we typically define as taste---is created by a combination of taste and olfactory information.

REFERENCE:

Vanderah TW, Gould DJ. Nolte's The Human Brain. 7th ed. Philadelphia, PA. Elsevier; 2016.