Trigeminal substance P-like immunoreactive fibres in the frog olfactory mucosa

The location and distribution of nerve fibres displaying substanceP (SP) immunoreactivity were studied in the frog olfactory mucosa.Many immunoreactive nerve fibres were noted in close associationwith Bowman's glands and blood vessels in the lamina propria.In addition, such fibres were also found beneath and withinthe olfactory epithelium proper. These fibres are clearly oftrigeminal origin since SP immunoreactivity was abolished aftersection of the trigeminal nerve. Functionally, they might influencelocal blood flow, secretion of Bowman's glands and/or activityof olfactory receptor cells.