An immunocytochemical study of calbindin-D28K in laminae I and II of the dorsal horn and spinal ganglia in the chicken with special reference to the relation to substance P-containing primary afferent neurons.
The localization of calbindin-D28K (CB) was studied immunocytochemically in laminae I and II of the dorsal horn and in spinal ganglia in the chicken, and compared with the distribution of substance P (SP) using double immunolabeling. At the light microscopic level, CB immunoreactivity was observed most intensely in the lamina II using the avidin-biotinylated peroxidase complex (ABC) and immunofluorescence methods. At the electron microscopic level using the ABC method, CB immunoreactivity was observed in the following three neuronal elements: 1) the scalloped central terminal with many dense-cored vesicles (DCVs) in the synaptic glomerulus; 2) some vesicle-containing dendrites (VCDs) inside or outside the synaptic glomerulus; and 3) some axon terminals outside the synaptic glomerulus. The CB-immunoreactive (IR) VCDs in the synaptic glomerulus often formed reciprocal synapses with the central terminal. Strong immunoreactivity was observed at the postsynaptic membrane of CB-IR elements. Double immunofluorescence and immunolabeling methods at the electron microscopic level showed that CB and SP colocalized in the scalloped central terminal with DCVs of the synaptic glomerulus. Almost all SP-IR neurons in the spinal ganglion revealed the coexistence of CB in serial sections in the chicken. In light of previous biochemical and physiological reports, our findings suggest that CB - coexisting with SP - plays an important role in the control of pain transmission through its strong Ca(2+)-buffering action in the chicken.
Li
Yong-Nan
YN
Department of Anatomy, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, Yamanashi 409-3898, Japan.
Sakamoto
Hiroshi
H
Kawate
Toyoko
T
Cheng
Chang-Xie
CX
Li
Yan-Chao
YC
Shimada
Osamu
O
Atsumi
Saoko
S
D000818:Animals; D064026:Calbindins; D002645:Chickens; D003712:Dendrites / Q000378:metabolism / Q000648:ultrastructure; D005727:Ganglia, Spinal / Q000378:metabolism* / Q000648:ultrastructure; D007150:Immunohistochemistry; D046529:Microscopy, Electron, Transmission; D009475:Neurons, Afferent / Q000378:metabolism* / Q000648:ultrastructure; D020671:Posterior Horn Cells / Q000378:metabolism / Q000648:ultrastructure; D017729:Presynaptic Terminals / Q000378:metabolism; D064030:S100 Calcium Binding Protein G / Q000378:metabolism*; D013116:Spinal Cord / Q000378:metabolism* / Q000648:ultrastructure; D013373:Substance P / Q000378:metabolism*
D064026:Calbindins; D064030:S100 Calcium Binding Protein G; D013373:Substance P