Morphology Of The Sacral Micturition Reflex Mechanism Based Discussion

The clinical and electrophysiological studies have shown that transection of the spinal cord above the level of the sacral parasympathetic nucleus (SPN) makes the micturition reflex reorganized. The reorganization implies that the spinal-brain stem-spinal micturition reflex through the 'pontine micturition center' in the animal with intact neuraxis is replaced by the spinal reflex through the sacral parasympathetic pathways. The latter reflex is characterized by direct efferent response to the information from peripheral afferent. The sacral parasympathetic nucleu is the basic centre of the reflex. However, the mechanism of this reorganization is unanswered in the past. The hypothesis that the 'spinal reflex is unmasked' was proposed by de Groat with his collaborators in order to explain the mechanism. But because of the lack of morphological, especially the ultrastructural evidence their explanation was limited to the imagination. In order to investigate the morphological basis for the "hypothesis', the authors...