Credit: Molecular Psychiatry (2025). The olfactory epithelium is a region very close to the brain located at the top part of the nostrils, where the olfactory neurons that allow us to smell are located. The olfactory epithelium also contains neural stem cells that can be extracted by means of nasal exfoliation. More information: Paula Unzueta-Larrinaga et al, Extracellular matrix dysfunction and synaptic alterations in schizophrenia, Molecular Psychiatry (2025). DOI: 10.1038/s41380-025-03154-2 Journal information: Molecular Psychiatry