Premium
Spinal and medullary projections to the parabrachial nuclear complex
Author(s) -
Panneton W. Michael,
Gan Qi,
Haque Qudsia
Publication year - 2007
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.21.6.a1271-c
Subject(s) - parabrachial nucleus , spinal cord , anatomy , medulla , pons , lateral parabrachial nucleus , nociception , medulla oblongata , medullary cavity , neuroscience , nucleus , lamina , central nervous system , dorsum , biology , chemistry , medicine , receptor
Numerous neuroanatomical studies have described spino/medullary parabrachial projections, and neurophysiological studies have implicated them as important in pain. The parabrachial complex however is subdivided into several subnuclei, two of which receive nociceptive input, and another important in respiration. We suggest different origins of fibers from the spinal cord and medulla to these different parabrachial targets. Injections of the retrograde tracer FluoroGold (FG) were centered either in the parabrachial nucleus laterally (PBl; including the external lateral and dorsal subnuclei), dorsally (PBd; including the internal lateral and ventral subnuclei), or ventrally ( Kölliker‐Fuse area; KF) in rats. After 8–12 days the rats’ brains and spinal cords were processed immunohistochemically for FG. Numerous neurons were labeled in lamina I of the medullary and spinal dorsal horns after injections into the PBl; far fewer were noted in the caudal pressor area (CPA) or lateral spinal nucleus (LSN). Injections in the PBd resulted in fewer labeled neurons in lamina I, but many more in the CPA and LSN. Injections of FG into the KF area resulted in numerous labeled neurons in lamina V of the MDH but fewer in lamina I. Injections of BDA into laminae I or V, the CPA, or LSN confirmed the FG injections. This suggests ascending axons selectively target functionally different targets in the parabrachial complex. Supported by NIH grant HL 64772.