Contribution of supraspinal and spinal structures to the responses of dorsal spinal cord blood flow to innocuous cutaneous brushing in rats.
Responses of dorsal spinal cord blood flow (SCBF) to innocuous mechanical cutaneous stimulation were investigated in anesthetized central nervous system intact (CNS-intact) and C2 spinalized rats. SCBF was recorded at the L4-L6 level with a laser Doppler flowmeter. SCBF increased with brushing of the ipsilateral proximal hindlimb and hindpaw, and there were no significant differences in the magnitudes of the responses in CNS-intact and spinalized animals. Brushing of the lower back had no effect on SCBF at the L4-L6 level in either cohort. Brushing stimulation produced no significant changes in systemic arterial blood pressure. The responses of SCBF to brushing in CNS-intact animals were diminished by pretreatment with phenoxybenzamine, an alpha-adrenoceptor blocking agent, but no such effects were seen in spinalized animals. These results indicate that innocuous mechanical cutaneous input can produce a segmentally-organized increase in regional SCBF, and that the responses are modulated, in part at least, by alpha-adrenergic receptors via supraspinal structures.
Kurosawa
Mieko
M
Center for Medical Science, International University of Health and Welfare, Otawara, Tochigi 324-8501, Japan. mieko-ku@iuhw.ac.jp
Toda
Hiroko
H
Watanabe
Orie
O
Budgell
Brian
B
D000317:Adrenergic alpha-Antagonists / Q000494:pharmacology; D000344:Afferent Pathways / Q000502:physiology*; D000818:Animals; D017776:Autonomic Pathways / Q000502:physiology; D001921:Brain / Q000502:physiology*; D003714:Denervation; D004525:Efferent Pathways / Q000502:physiology; D017078:Laser-Doppler Flowmetry; D008297:Male; D008465:Mechanoreceptors / Q000502:physiology*; D010812:Physical Stimulation; D051381:Rats; D017208:Rats, Wistar; D011942:Receptors, Adrenergic, alpha / Q000187:drug effects / Q000502:physiology; D012039:Regional Blood Flow / Q000502:physiology*; D012867:Skin / Q000294:innervation; D012879:Skin Physiological Phenomena; D013116:Spinal Cord / Q000098:blood supply / Q000502:physiology*; D013119:Spinal Cord Injuries / Q000503:physiopathology; D013564:Sympathetic Nervous System / Q000502:physiology; D014110:Touch / Q000502:physiology*
D000317:Adrenergic alpha-Antagonists; D011942:Receptors, Adrenergic, alpha