Olfactory receptors in your brain transform the chemical signatures of odors into electrical signals (as opposed to physical nerve signals). An odor molecule binds to the olfactory receptors in the nasal mucosa that line your nostrils. This triggers neurons to send messages to your brain. Your olfactory nerve, aka the first cranial nerve, carries these signals directly to the frontal lobe.
Our brain categorizes odors into two categories: good and bad. Good smells activate serotonergic systems to release oxytocin. We feel good, happy, and satisfied. Bad smells activate the dopaminergic system, norepinergic system, and epinergic system. These systems kick in our fight-or-flight reaction. We feel bad, scared and repulsed.
This disorder is similar to tinnitus. A large percentage of Superficial Siderosis patients who experience phantosmia progress to anosmia.
Updated: June 16, 2018