Relationship of NK3 receptor- immunoreactivity to subpopulations of neurons in rat spinal cord

✍ Scribed by Seybold, V.S.; Grkovic, I.; Portbury, A.L.; Ding, Y.-Q.; Shigemoto, R.; Mizuno, N.; Furness, J.B.; Southwell, B.R.

• Publisher: John Wiley and Sons
• Year: 1997
• Tongue: English
• Weight: 429 KB
• Volume: 381
• Category: Article
• ISSN: 0021-9967
• DOI: 10.1002/(sici)1096-9861(19970519)381:4<439::aid-cne4>3.0.co;2-3

✦ Synopsis

The distribution of immunoreactivity to the neurokinin 3 receptor (NK3R) was examined in segments C7, T11-12, L1-2, and L4-6 of the rat spinal cord. NK3R immunoreactivity was visualized by using two antisera generated against sequences of amino acids contained in the C-terminal region of the NK3R. NK3R-immunoreactive cells were numerous in the substantia gelatinosa of all spinal segments examined as well as the dorsal commissural nucleus of spinal segments L1-2. Isolated, immunoreactive cells were scattered throughout other regions of the spinal cord. The relationship of NK3R-immunoreactivity with neurons was demonstrated by colocalization with microtubule associated protein 2-immunoreactivity in individual cells. Within neurons, NK3R-immunoreactivity was associated predominately with the plasma membrane of cell bodies and dendrites. Within the substantia gelatinosa, 86% of nitric oxide synthase (NOS)-immunoreactive neurons were also NK3R-immunoreactive. Although NOSimmunoreactive neurons were found throughout all other regions of the spinal cord in the segments examined, these were not NK3R-immunoreactive. When preganglionic sympathetic neurons in spinal segments T11-12 and L1-2 were visualized by intraperitoneal injection of Fluorogold, less than 1% of the Fluorogold-labeled neurons were also immunoreactive for NK3R. The large number of NK3R-immunoreactive neurons in the substantia gelatinosa suggests that some effects of tachykinins on somatosensation may be mediated by NK3R.