Supraspinal connections and termination patterns of the parabrachial complex determined by the biocytin anterograde tract‐tracing technique in the rat

• DOI: 10.1046/j.1469-7580.1998.19330417.x
• Publication Date: 2003-03-12T07:21:51Z
• Authors: ROSSELLA BIANCHI; GIOVANNI CORSETTI; LUIGI RODELLA; GIOVANNI TREDICI; MAGDA GIOIA
• Keywords: Biocytin; Tracing; Anterograde tracing

We have re‐evaluated, using the anterograde tracer biocytin, supraspinal efferent projections from parabrachial complex (PBN) to gain new information about nature of its connections and nerve terminal patterns. selectively injected biocytin into 3 main regions nucleus (lateral PBN, medial PBN Kölliker‐Fuse nucleus). observed distinct groups ascending descending fibres different calibre running throughout brain reaching many areas involved in regulation autonomic function. Here we detected labelled bouton‐like terminals with en‐passage varicosities. The efferents lateral mainly reached reticular, raphe thalamic nuclei, zona incerta (ZI), central amygdala (CeA) area periaqueductal grey (PAG). Thin ventral region solitary tract (STN). were seen reticular PAG, nuclei amygdala. Descending STN some nuclei. targeted CeA, ZI, hypothalamic area, ventromedial and, only a few terminals, ipsi contralateral area. A large number STN, caudal paragigantocellular higher sensitivity compared other types markers allowed us determine more effectively distribution, extent connections. This suggested that several circuits probably plays important role than previously thought.