CNS SITES INVOLVED IN SYMPATHETIC AND PARASYMPATHETIC CONTROL OF THE PANCREAS - A VIRAL TRACING STUDY

The viral transneuronal tracing method was used to identify the CNS ce ll groups that regulate the parasympathetic and sympathetic outflow sy stems of the pancreas. Pseudorabies virus (PRV) was injected into the pancreas of vagotomized rats and after 6 days survival, the pattern of transneuronal labeling in the CNS sympathetic regulatory regions was determined. The converse experiment was performed in order to elucidat e the central parasympathetic cell groups that regulate the pancreas. Immunohistochemical methods were used to identify putative neuropeptid e-and catecholamine-containing CNS neurons involved in these regulator y circuits. The major finding of this study indicates that five brain regions, viz., paraventricular hypothalamic nucleus, perifornical hypo thalamic region, A5 catecholamine cell group, rostral ventrolateral me dulla, and lateral paragigantocellular reticular nucleus, contain a co nsiderable amount of overlap in cell body labeling. In addition, the v entrolateral part of the periaqueductal gray matter and gigantocellula r reticular nucleus, ventral part also showed a similar overlap, but t he numbers of neurons found in these areas were considerably lower tha n the five major regions. These data suggest that these brain regions may provide parallel and possibly redundant, autonomic pathways affect ing glucagon and adrenaline release. (C) 1997 Elsevier Science B.V.