Presented at a scientific meeting of the Physiological Society at the University of Bristol in September 2001.
Pain Pathways and Parabrachial Circuits in the Rat
Article first published online: 4 MAY 2004
Volume 87, Issue 2, pages 251–258, March 2002
How to Cite
Gauriau, C. and Bernard, J.-F. (2002), Pain Pathways and Parabrachial Circuits in the Rat. Experimental Physiology, 87: 251–258. doi: 10.1113/eph8702357
- Issue published online: 4 MAY 2004
- Article first published online: 4 MAY 2004
- Cited By
This review presents a schematic attempt to classify the major pain pathways, based on the results of recent studies in our laboratory, with a special emphasis on the parabrachial system. Our view is based on results from experiments in the rat, using very small iontophoretic injections of anterograde tracers. As illustrated in this report, we have found a very dramatic difference between ascending projections originating from deep laminae compared with those arising from lamina I of the dorsal horn. We propose three main pain systems and discuss their functional-anatomical relationships. The first system is centred on the projection from deep laminae to three caudal reticular areas – the lateral reticular nucleus (LRN), the subnucleus reticularis dorsalis (SRD) and the gigantocellular lateral paragigantocellular reticular nuclei (NGc) – and the parabrachial internal lateral subnucleus (PBil). The second system is centred on the projection from lamina I to the ventral posterolateral nucleus (VPL), the ventral posteromedial (VPM), the posterior nuclear group (Po) and triangular posterior nucleus (PoT) of the thalamus. The third system is centred on the projection from lamina I to the lateral parabrachial area. We also present the four main projections from the latter area to the extended amygdala, the hypothalamus, the periaqueductal grey matter (PAG), and the ventrolateral medulla (VLM), and their involvement in emotional and autonomic (homeostatic) aspects of pain.