Cerebrovascular parasympathetic innervation contributes to coupling of neuronal activation and blood flow in rat somatosensory cortex.
We measured the increase of regional cerebral blood flow (rCBF) in the somatosensory cerebral cortex occurring in response to a standard stimulation of the L. side mystacial vibrissae (facial whiskers) in rats anaesthetised with halothane, in conjunction with blocking of activity in the R. side parasympathetic (PS) and sensory fibres innervating the cerebral vessels. Blocking was achieved reversibly and repeatedly by means of a cooling probe. When the PS fibres and the nasociliary nerve (NCN) were blocked together, but not when the NCN was blocked alone, the R. side rCBF increase occurring with whisker stimulation was significantly reduced. Our results indicate that, in addition to the intrinsic cortical factors demonstrated in earlier studies, the cerebrovascular PS innervation, but not the NCN, contributes to the increase in cortical rCBF associated with somatosensory cortical neuronal activation.
D000818:Animals; D002560:Cerebrovascular Circulation / Q000502:physiology*; D004558:Electric Stimulation; D008297:Male; D009412:Nerve Fibers / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012039:Regional Blood Flow / Q000502:physiology*; D013003:Somatosensory Cortex / Q000502:physiology*; D013997:Time Factors