Apparatus is provided that includes one or more electrodes, configured to be applied to a sphenopalatine ganglion (SPG), a greater palatine nerve, a lesser palatine nerve, a sphenopalatine nerve, a communicating branch between a maxillary nerve and an SPG, an otic ganglion, an afferent fiber going into the otic ganglion, an efferent fiber going out of the otic ganglion, an infraorbital nerve, a vidian nerve, a greater superficial petrosal nerve, or a lesser deep petrosal nerve and a control unit, configured to drive the electrodes to apply electrical stimulation to the site, and configure the stimulation to excite nervous tissue of the site at a strength sufficient to induce at least one neuroprotective occurrence selected from the group consisting of: an increase in cerebral blood flow (CBF), and a release of one or more neuroprotective substances, and insufficient to induce a significant increase in permeability of a blood-brain barrier (BBB).
