Scientists have just mapped the nose for the first time. It turns out our sense of smell is far more organised than we ever imagined, paving the way for new treatments for smell loss. (Photo: Unsplash)

Hidden map found inside human nose through which smell travels to brain

Harvard researchers have discovered that smell receptors are organised into precise horizontal stripes within the nose. This first-ever smell map could lead to new treatments for those who have lost their sense of taste and odour.

by · India Today

In Short

  • Researchers found that smell receptors are organised in horizontal stripes.
  • Retinoic acid acts as a GPS for neurons in the nose.
  • The map in the nose aligns with the brain's maps.

For decades, the human nose was a biological enigma. While we understood how our eyes map light and our ears map sound, the way we perceive smells seemed chaotic.

However, a groundbreaking study by Harvard Medical School, published in the journal Cell on April 28, 2026, has finally cracked the code.

Scientists have created the first-ever smell map, revealing a hidden, highly organised structure within our nostrils.

HOW DOES THE NOSE ORGANISE DIFFERENT SMELLS?

Earlier, scientists believed that the thousand-plus types of smell receptors in the nose were scattered randomly.

This new research, conducted on mice, proves otherwise. The receptors are actually arranged in strict horizontal stripes, layered from the top of the nose to the bottom.

A microscopic view of the mouse nose showing the colourful organisation of smell neurons. (Photo: Datta Lab)

Each stripe is dedicated to a specific type of receptor. This spatial transcriptomics, a method that allows scientists to see exactly where genes are active in a tissue, showed that the nose is as organised as a library.

WHAT IS THE ROLE OF RETINOIC ACID IN SMELL?

The study identified a molecule called retinoic acid as the master conductor.

Retinoic acid is a derivative of Vitamin A that helps cells decide what they want to be during development.

Harvard researchers have discovered that smell receptors are organised into precise horizontal stripes within the nose. (Photo: Unsplash)

In the nose, a gradient of this acid acts like a GPS, telling each neuron which smell receptor to express based on its physical location.

If you change the levels of retinoic acid, the entire smell map shifts. This explains how millions of neurons find their place during growth.

HOW DO SMELL SIGNALS REACH THE BRAIN?

The researchers found that this map in the nose perfectly aligns with the smell map in the olfactory bulb, the brain's primary processing centre for odours.

This means there is a direct, predictable path from the nostril to the mind. Understanding this connection is vital for treating anosmia, or the loss of smell.

The new data explains how signals move from the nose to the olfactory bulb in the brain. (Photo: Getty)

Since smell is linked to memory and emotion, 100 per cent of our psychological well-being depends on this sensory input.

By decoding this map, scientists can now work on therapies like stem cell treatments to restore this essential sense.

- Ends