Co-existence of calcium-binding proteins and gamma-aminobutyric acid or glycine in neurons of the rat medullary dorsal horn
Wang, W.; Wu, S-xi.; Li, Y-qing.
Chinese Medical Journal 117(3): 430-433
2004
ISSN/ISBN: 0366-6999 PMID: 15043786 Document Number: 581480
Background We investigated the co-expression of calbindin-D28k ( CB), calretinin (CR) and parvalbumin (PV, a combination of the three is referred to as CaBPs) with gamma-aminobutyric acid (GABA) or glycine in neurons of the rat medullary dorsal horn (MDH). Methods Immunofluorescence histochemical double-staining for CaBPs and GABA or glycine was performed on the sections from rat MDH. Results CB-, CR-, PV-, GABA- and glycine-like immunoreactive (LI) neurons were differentially observed in all layers of the MDH, but particularly in lamina II. Neurons that exhibited immunoreactivity for both CaBPs and GABA or glycine were also observed mainly in lamina II. A few of them were found in laminae I and Ill. The percentages of neurons which co-expressed CB/GABA or CB/glycine out of the total numbers of CB- and GABA-LI neurons or CB- and glycine-LI neurons were 5.3% and 12.1% or 4.1% and 10.0%, respectively. The ratios of CR/GABA or CR/glycine coexisting neurons out of the total numbers of CR- and GABA-LI neurons or CR- and glycine-LI neurons were 5.8% and 7.6% or 4.4% and 7.1%, respectively. The rates of PV/GABA or PV/glycine colocalized neurons out of the total numbers of PV- and GABA-LI neurons or PV- and glycine-LI neurons were 11.1% and 5.1% or 9.9% and 5.1%, respectively. Conclusion The results indicate that some neurons in the MDH contain both CaBPs and GABA or glycine.