The nervus terminalis, also referred to as cranial nerve zero, cranial nerve XIII, zero nerve, nerve N or NT, is a previously unnumbered cranial nerve, most rostral of all cranial nerves.
It is a bilateral bundle of nerve fibers, which runs in the subarachnoid space from the medial olfactory stria on the inferior surface of the frontal lobe, to and through the cribriform plate, to the nasal septum. It runs medially to the olfactory nerve, over the surface of the gyrus rectus.
The terminal nerve originates from the neural crest, distinct and separate from the olfactory nerve (which originates in the nasal placode).
Whilst not mentioned in recent editions of anatomy textbooks by Last or Gray, the nervus terminalis carries a number of key functions: in embryogenesis it acts as a migration route for LHRH cells and as such is probably implicated in pathogenesis of Kallman syndrome.
In adults, based on animal studies, the nerve may be involved in reproductive behavior consisting of modulatory neurons.
High-resolution modern MRI scanners that achieve voxel size of 0.6-0.7 mm should be able to adequately display the nerve and assess for its lesions. Cohort serial studies demonstrating this are pending.
- 1. Vilensky JA. The neglected cranial nerve: nervus terminalis (cranial nerve N). Clin Anat. 2014;27 (1): 46-53. doi:10.1002/ca.22130 - Pubmed citation
- 2. Whitlock KE. Development of the nervus terminalis: origin and migration. Microsc. Res. Tech. 2004;65 (1-2): 2-12. doi:10.1002/jemt.20094 - Pubmed citation
- 3. von Bartheld CS, Baker CV. Nervus terminalis derived from the neural crest? A surprising new turn in a century-old debate. Anat Rec B New Anat. 2004;278 (1): 12-3. doi:10.1002/ar.b.20016 - Pubmed citation
- 4. Wirsig-Wiechmann CR, Wiechmann AF, Eisthen HL. What defines the nervus terminalis? Neurochemical, developmental, and anatomical criteria. Prog. Brain Res. 2003;141: 45-58. doi:10.1016/S0079-6123(02)41083-7 - Pubmed citation