A New Look to Understanding the Autonomic Innervation of the Digestive Tract: The Novel Concept of a Neural Plexus Freeway and Its Clinical and Physiological Significance

Introduction: We originally described in the literature that neural fibers jump the duodeno pancreaticcleft plexus (DPCP) in human cadavers. The DPCP was explored in rats, dogs, and opossum, and it allowed us to elaborate a “neural plexual freeway” (NPF). Methods: Bile pancreatic fistula in rats. Thomas cannula and Secretin test in dogs. Choline acetylase (cholinergic tone) in pancreas. Histochemistry analyses at different levels by optical microscopy Results: Crowning fifty decades of clinical and experimental research allowed us to elaborate the present hypothesis, one that describes the exquisite modulation of the autonomic nervous system over the digestive tract innervations. This theory hinges on the activity of three modulatory centers(MC). The first upper segment, describedelsewhere, is a distributor of “autonomic arc reflexes”(AAR). Its epicenter is the antro-fundus-junction(AFJ). A cicatricial barrier(CB) at this level elicits a peptic ulcer. The second MC is the peri-Vaterian region(PVR). This is a significant cholinergic center. Topical anesthesia on PVR depresses intra-pancreatic cholinergic tone. Its irritation elicits crucial AAR(vagal, splanchnic-celiac, pseudo-axonic), as observed in episodes of biliary-acute pancreatitis. This region is, in fact, our so-called “trigger” of a pancreatic revolver. The interference at this region in the DPCP also induces a fall of the pancreatic cholinergic tone, resulting in pancreatic head hypertrophy. Regarding the third MC, its notionstarted with our finding - in conscious dogs with Thomas cannula in the ileo-cecal region(ICR) - that sorbitol instillation releases an inhibitory factor that exerts a depressing effect on secretin-induced exocrine pancreatic secretion. We postulate that an associated sympatheticpeptide is the basis of an “ascending inhibitory wave”(AIW). This AIW flows up and modulates the PVR. In addition, after entering into the hepatic-ductal tree, AIW regulates the autonomic innervation of the hepatic gland, explaining why the interference generated by a CB increases the parasympathetic tone of the gland and subsequently enhances Lautt's factor or “HISS”(hepatic insulin sensitizing substance). Conclusion: CB, a simple and straightforward surgical procedure, when performed in the appropriate region of our NPF, induces a remarkable change, that of an enhanced insulin sensitivity. The latter plays a well-documented, critical role in obesity and metabolic syndrome.Figure 1