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