Reflex modulation of visceral functions by acupuncture-like stimulation in anesthetized rats

Our recent studies of the neural mechanisms of the reflex effects on visceral functions of acupuncture-like stimulation applied to the skin and underlying muscle by twisting a needle in anesthetized rats are reviewed. Gastric motility was inhibited by acupuncture-like stimulation of the abdominal areas and facilitated by limb stimulation. The rhythmic micturition contractions of the urinary bladder were inhibited by stimulation of the perineal area. Responses of sympathoadrenal medullary function to acupuncture-like stimulation were inconsistent. Blood pressure responses were inconsistent, but in a deep anesthetized condition, acupuncture-like stimulation applied to the hindlimb muscles caused a decrease in blood pressure. Each of the responses observed was a reflex response whose afferent pathways consisted of cutaneous and muscle afferent nerves and efferent pathways consisted of the autonomic efferent nerves. The reflex center was in the central nervous system (CNS). Some of these reflexes were characterized by segmental organization and others by nonsegmental organization. The spinal cord was essential for the segmental reflexes, while the supraspinal cord was essential for the nonsegmental generalized reflexes. The generalized reflex was elicited by stimulation to various spinal segments, particularly by stimulation to limbs. (C) 2002 Elsevier Science B.V. All rights reserved.