5-HT1D receptor immunoreactivity in the sphenopalatine ganglion: implications for the efficacy of triptans in the treatment of autonomic signs associated with cluster headache

Abstract

Objective. - To determine if 5-HT1D receptors are located in the sphenopalatine ganglion. Background. - While the 5-HT1D receptor has been described in sensory and sympathetic ganglia in the head, it was not known whether they were also located in parasympathetic ganglia. Methods. - We used retrograde labeling combined with immunohistochemistry to examine 5-HT 1D receptor immunoreactivity in rat sphenopalatine ganglion neurons that project to the lacrimal gland, nasal mucosa, cerebral vasculature, and trigeminal ganglion. Results. - We found 5-HT1D receptor immunoreactivity in nerve terminals around postganglionic cell bodies within the sphenopalatine ganglion. All 5-HT1D-immunoreactive term..