How taste buds are wired into your brain to experience flavors

Discovering the inner workings of the human body is a continually evolving process and sometimes a challenging one. Take for instance our taste buds, those important receptors on our tongue that discern sweet from salty and bitter from sour. Humans are generally wired to favor sweet flavors versus bitter ones is a survival instinct, as bitter flavors could mean something is toxic or poisonous.

The taste system is a remarkable one, and while we’ve known where the different taste receptors are located on the tongue and how they transmit flavors to the brain, not much is known about the actual wiring of new taste receptors. This could be because taste receptor cells, the ones that actually sense flavor, die off and replace themselves almost every two weeks.

The high turnover rate, while impressive, also begs the question, how do the taste cells correctly rewire themselves every time and continue to send the right signals to the brain?

Charles Zuker, a Howard Hughes Medical Institute investigator from Columbia University saw that there was very little known about how the taste cells are wired into the taste system and brain, and so he set about to try and understand more about this process.

Zuker and his colleagues observed different groups of mice essentially “tangling” or mixing up the taste receptors in different groups, which allowed them to see how the miswired taste receptors reacted to bitter and sweet flavors.

What the researchers discovered was that specific chemical signals in new taste receptor cells can attract the correct nerve connections to them and in turn send the right flavor signals to the brain.

“As new taste cells are born, they provide the right instructions to establish the right connection,” said Zuker.

Taste receptors have a hugely important job and must be rewired correctly every time they are replaced in order for the taste system to work. Zuker’s research helps solve the mystery of how taste receptors are wired and helps shed further light on the evolution of human taste processes.

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By Kay Vandette, Earth.com Staff Writer