Olfactory tract
Tractus olfactorius
Definition
The olfactory tract is a narrow bundle of nerve fibres formed mainly by the axons of mitral and tufted cells of the olfactory bulb. It extends posteriorly from the bulb within the olfactory sulcus on the inferior surface of the frontal lobe, carrying olfactory information that has already undergone initial processing in the bulb. Unlike the olfactory nerve, it therefore does not contain the primary axons of olfactory receptor neurons. Near the anterior perforated substance, the tract expands into the olfactory trigone, where its fibres diverge principally into the lateral and medial olfactory striae.
References
Purves D, Augustine GJ, Fitzpatrick D, et al., editors. Neuroscience. 2nd edition. Sunderland (MA): Sinauer Associates; 2001. The Olfactory Bulb. Available from: https://www.ncbi.nlm.nih.gov/books/NBK11158/
Snell, R.S. (2010). ‘Chapter 11: The cranial nerve nuclei and their central connections and distribution’, in Clinical Neuroanatomy. (7th ed.) Philadelphia: Wolters Kluwer Health/Lippincott Williams & Wilkins, pp.331-370.
De Cannière G. The olfactory striae: A historical perspective on the inconsistent anatomy of the bulbar projections. J Anat. 2024 Jan;244(1):170-183. doi: 10.1111/joa.13952. Epub 2023 Sep 15. Erratum in: J Anat. 2026 Jul 14.
