The dominance of outflow from the brain to the VVVP may be analogous to the typical dominance of the IJVs in humans in the supine position.

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Many complications associated with paraplegia (e.g. spasticity, autonomic dysreflexia, neurogenic bladder) are mediated, in part, by plasticity within the autonomic nervous system. An under investigated complication associated with paraplegia is an increased susceptibility to ventricular arrhythmias. Therefore, we tested the hypothesis that paraplegia‐induced plasticity within the autonomic nervous system is associated with an increased susceptibility to ventricular arrhythmias. Cardiac nerve growth factor content (ELISA), cardiac sympathetic nerve density (immunopositive for tyrosine hydroxylase) and the susceptibility to arrhythmias (coronary artery occlusion) were determined in intact and paraplegic (4 weeks post transection) rats. Paraplegia, compared to intact, increased cardiac nerve growth factor content (2667 ± 326 pg/ml vs 333 ± 51 pg/ml), cardiac sympathetic innervation density (78 μm2/mm2 vs 23 μm2/mm2), and decreased the ventricular arrhythmia threshold (3.6 ± 0.2 min vs 4.9 ± 0.2 min). Thus, neuroplasticity of autonomic behavior increases the susceptibility to ventricular arrhythmias in paraplegic rats. Supported by HL088615