Structure and Visibility
- The terminal nerve is a microscopic plexus of unmyelinated peripheral nerve fascicles.
- It appears near the cribriform plate and travels posteriorly toward the olfactory trigone, medial olfactory gyrus, and lamina terminalis.
- The nerve is often overlooked in autopsies due to its thinness and is often torn out when exposing the brain.
- Careful dissection is necessary to visualize the nerve.
- The nerve is not commonly mentioned in anatomy textbooks.

Development
- The zebrafish has been used as a developmental model in studying the terminal nerve.
- The connections between the terminal nerve and the olfactory system have been extensively studied in human embryos.
- The nerve enters the brain at stages 17 and 18 from olfactory origins.

Function
- The terminal nerve is not connected to the olfactory bulb, suggesting it may be vestigial or involved in sensing pheromones.
- It projects to the medial and lateral septal nuclei and the preoptic areas, which are involved in regulating sexual behavior in mammals.
- A study in hamsters found that mating is reduced when the terminal nerve is severed.

Additional Images
- Three forms of the nerve can be observed on the underside of human brains.
- The gyrus rectus can be seen at the anterior center when viewing the brain from below.

Related Topic
- Vomeronasal organ

Terminal nerve (Wikipedia)

The terminal nerve, also known as cranial nerve 0 or simply as CN 0, is a nerve that was not included in the seminal classification of the cranial nerves as CN I through CN XII but is now generally classified as a cranial nerve. It was discovered by German scientist Gustav Fritsch in 1878 in the brains of sharks. It was first found in humans in 1913. A 1990 study has indicated that the terminal nerve is a common finding in the adult human brain. The nerve has been called unofficially by other names, including cranial nerve XIII, zero nerve, nerve N, and NT.

Cranial nerve zero
Left The terminal nerve as it is shown on the ventral side of a dog-fish brain. (Topmost label)
Details
Identifiers
Latinnervus terminalis
TA98A14.2.01.002
TA26179
FMA76749
Anatomical terminology
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