Localized neural control of blood flow in the posterior region of the knee joint in anaesthetized rabbits.

Radiolabelled microspheres were used to measure blood flow of structures in and around the rabbit knee joint and to determine the effect of electrical stimulation of the posterior articular nerve (PAN) supplying the knee. Surgical exposure of the posterior aspect of the knee joint 'capsule' and section of PAN resulted in an increase in flow restricted to this region. Electrical stimulation produced frequency-dependent reductions of blood flow in the posterior region, but no alterations occurred in the anterior region or in any other surrounding structures, suggesting that the neural supply is specific to the posterior joint capsule.