A method is provided that includes advancing at least one electrode through mucosa of an oral cavity, along a path that does not enter a greater palatine canal, to within 10 mm of a sphenopalatine fossa. The at least one electrode is left implanted within 10 mm of the sphenopalatine fossa. Optionally, the at least one electrode is advanced into the sphenopalatine fossa via a lateral aspect of the fossa, and left implanted in the sphenopalatine fossa. Other embodiments are also described.