Abstract
In anesthetized rats, responses of spinal cord blood flow to brushing of various cutaneous segmental areas were investigated. Regional spinal blood flow was measured with a laser Doppler flowmeter probe placed on the dorsal surface of the spinal cord in either the T12–L1 or L4–6 regions. Spinal blood flow recorded at the T12–L1 level was increased by brushing of the abdomen, proximal hindlimb or chest, but not by brushing of the forepaw, proximal forelimb or hindpaw. Spinal blood flow recorded at the L4–6 level was increased by brushing of the proximal hindlimb and hindpaw, but not by brushing of the forepaw, proximal forelimb, chest or abdomen. None of these brushing stimuli produced significant changes in systemic arterial blood pressure. These results indicate that innocuous cutaneous mechanical input can produce a segmentally-organized increase in regional spinal cord blood flow. Furthermore, the responses of spinal blood flow to brushing were diminished by pretreatment with phenoxybenzamine, an alpha adrenoceptor blocking agent, suggesting that the sympathetic nerves contribute to the responses of spinal blood flow to brushing. [Jpn J Physiol 55 Suppl:S189 (2005)]
