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Spinal projection neurons to the laterodorsal pontine tegmental nucleus: Relationship to preganglionic neurons and nitric oxide synthase
Author(s) -
Hamilton Murray O.,
Papka Raymond E.,
O'donoghue Daniel L.,
Vaidya Atul M.,
Williams Sonya J.,
Poff Clifton R. D.,
McNeill Daniel L.
Publication year - 1995
Publication title -
journal of comparative neurology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.855
H-Index - 209
eISSN - 1096-9861
pISSN - 0021-9967
DOI - 10.1002/cne.903530102
Subject(s) - tegmentum , biology , anatomy , spinal cord , nitric oxide synthase , pons , brainstem , neuroscience , retrograde tracing , nicotinamide adenine dinucleotide phosphate , diaphorase , nucleus , central nervous system , nitric oxide , endocrinology , midbrain , enzyme , biochemistry , oxidase test
The region of the rat sacral parasympathetic nucleus (SPN) contains distinct subpopulations of neurons that project supraspinally or are preganglionic neurons. Some preganglionic neurons in the SPN serve as the motor outflow for urinary bladder contraction; other neurons in the SPN project to regions of the rostral pons that subserve micturition reflexes. Previous studies utilizing immunohistochemistry or staining for nicotinamide adenine dinucleotide phosphate‐diaphorase (NADPH‐d) have demonstrated that numerous neurons in the SPN contain nitric oxide synthase (NOS), the enzyme for nitric oxide synthesis. Thus, the objectives of this study were to determine (1) the distribution of neurons in the region of the SPN that project to the laterodorsal tegmenturn (LDT) of the pons, (2) whether spinal neurons projecting to a peripheral autonomic ganglion also project to the LDT, and (3) whether NOS or NADPH‐d is present in LDT projection neurons. Preganglionic neurons were identified by injecting the retrograde tracer fluorogold (FG) into the major pelvic ganglion (MPG). Supraspinally projecting neurons were identified by injecting the retrograde tracer fast blue (FB) into the LDT. Numerous FB‐labeled neurons were present in the ipsi‐ and contralateral SPN and were immediately dorsal to FG‐labeled preganglionic neurons. Neurons containing both tracers were not observed. Approximately 20% of preganglionic neurons, but no LDT projection neurons, were reactive for NOS and NADPH‐D. These data suggest that the region of the SPN is a site for distinct subpopulations of neurons that project to the LDT and to the MPG and that NOS is contained in some preganglionic neurons, but is not a marker for LDT projection neurons. © 1995 Wiley‐Liss, Inc.