Scientists Reveal a Hidden “Smell Map” Connecting the Nose and Brain.

Harvard Medical School researchers have created the first detailed spatial map of how more than 1,100 types of olfactory receptors are organized in the mouse nose. Contrary to the long-standing idea that smell receptors are scattered somewhat randomly within broad regions, the team found that receptor-expressing neurons occupy precise, overlapping bands across the olfactory epithelium.

Using single-cell RNA sequencing, spatial transcriptomics, and advanced microscopy, researchers analyzed millions of olfactory sensory neurons from hundreds of mice. Each sensory neuron expresses one receptor type, and its position within the developing nasal tissue helps influence which receptor it selects. The signaling molecule retinoic acid appears to help establish this spatial organization.

Remarkably, this map in the nose aligns with the organization of corresponding neurons in the olfactory bulb—the brain’s first major processing center for smell. This suggests that olfaction, like vision, hearing, and touch, relies on an orderly topographic system linking sensory receptors to specific neural destinations.

The findings provide a new framework for studying how odors are encoded, how olfactory circuits develop, and why the sense of smell may be disrupted by infections, aging, injury, medications, or cancer treatments. The research could eventually inform strategies for treating anosmia and other smell disorders, although the work was conducted in mice and researchers have not yet established whether the same detailed organization exists in humans.

Study: Brann et al., Cell DOI: 10.1016/j.cell.2026.03.

#Neuroscience #Olfaction #SenseOfSmell #BrainResearch #SensoryNeuroscience #HarvardMedicalSchool #Neurobiology #SpatialTranscriptomics

The International Society for Stem Cell Research (ISSCR) today announced the presentation of new clinical data from the STEM-PD Phase I/II clinical trial at the ISSCR 2026 Annual Meeting. The study reports 12-month outcomes evaluating a cryopreserved, off-the-shelf dopaminergic progenitor cell product derived from human pluripotent stem cells for the treatment of Parkinson’s disease.

The findings provide new insights into the safety, feasibility, and biological activity of stem cell-derived dopaminergic cell transplantation in patients with Parkinson’s disease and represent another important step in the clinical translation of regenerative medicine for neurodegenerative disease.

“These data represent the culmination of decades of research aimed at translating stem cell biology into a clinically viable therapy,” said Malin Parmar, Professor in Cellular Neuroscience at Lund University, Sweden, who presented the findings today at the ISSCR 2026 Annual Meeting. “They demonstrate that a stem cell-derived dopaminergic cell product can be manufactured, delivered, and evaluated within a rigorous clinical trial framework. More broadly, they show that regenerative medicine is moving beyond proof-of-concept and into a stage where stem cell-based therapies are being tested in patients for complex neurodegenerative diseases.”

Age-related neurodegenerative disorders, including dementia, are a major global health concern. This article describes the first comprehensive, data-driven molecular model of the neuro-glia-vascular system to explore the complex relationships between the aging brain, energy metabolism, blood flow, and neuronal activity. Comprising 16,800 interaction pathways, the model includes all key enzymes, transporters, metabolites, and circulatory factors vital for neuronal electrical activity. We found significant alterations in metabolite concentrations and differential effects on adenosine triphosphate (ATP) supply in neurons and astrocytes and within subcellular compartments in aged brains and identified reduced sodium/potassium adenosine triphosphatase (Na⁺/K⁺-ATPase) activity as the leading cause of impaired neuronal action potentials.