Olfactory receptor expressed in ganglia of the autonomic nervous system

Certain members of the olfactory receptor superfamily appear to be expressed not only in chemosensory neurons of the nasal epithelium. Analyzing the transgenic mouse line MOL2.3-IGITL, the olfactory receptor subtype MOL2.3 was found to be expressed in distinct subpopulations of cells within a cranial, a cervical as well as within a thoracic ganglion. By means of coexpressed markers, the axonal processes of MOL2.3 expressing cells could be visualized and thus the target tissues innervated by these ganglionic neurons identified. Stained fibers, but no stained cell bodies were visible in distinct head regions, notably in the lateral nasal gland and in the so-called Harderian gland; staining was also observed on distinct segments of blood vessels, especially within the tongue. In the thoracic region, the heart and a small segment of the aorta as well as a distinct population of lung alveoli were labeled by incoming blue fibers. Expression of MOL2.3 in cells of the autonomic nervous system supports the idea that at least some of the multiple olfactory receptor types serve functions others than odorant detection.