In transmembrane and intracellular sites of neurom, calcium ion(Ca++) has been known to have an important role of signalling process. It is now well accepted that calcium binding proteins, calbindin D-28K (calbindin) and parvalbumin, modulate and
mediate above aclcium ions's action as a second messenger. Although it has been reported that calbindinergic and parvalbuminergic neurons comprise different subpopulations in the cat and rat spinal cords, the studies of their morphology,
topographical
distribution and ultrastructural features have not been done extensively in the mammalian spinal cords until now. This study was conducted to localize calbidinergic and parvalbuminergic neurons and define their morphology, topographical
distribution and
ultrastructural features in the rabbit cervical cord by the preembedding immunocytochemical method using anti0calbindingand anti-parvalbumin antisera.
In the rabbit cervical cord, calbindin immunoreactive neurons were mainly distributed in the dorsal horn, especially in lamina II, and a small number of labelled neurons were observed in the intermediate gray matter (IGS), but calbindin
immunoreactivities were not observed in the intermediate gray substance(IGS), but calbindin immunoreactiveties were not observed in thr ventral horn. The somata of calbindin immunoreactive neurons received synaptic inputs from non-immunoreactive
axon
terminals in the dorsal horn and in the IGS. Parvalbumin immunoreactive neurons were mainly observed in the IGS and in the ventral horn, but only a few of parvalbumin immunoreactive neurons were distributed in the dorsal horn. In the ventral
horn,
two
types of parvalbumin immunoreactive neurons were identified according to the sized of the somata and labelled motor cells received synaptic inputs from labelled and unlabelled axon terminals.
These results demonstrate that calbindinergic neurons are a number of neurons located in lamina II of dorsal horn and a few of neurons located in the intermediate gray and parvalbuminergic neurons are laocated in the intermediate gray substance
and
in
the ventral horn, and these neurons comprise different subpopulations of neurons.
It was suggest that calbindinergic neurons might play an important role in the process of pain modulation and parvalbumiergic neurons in the control of motor activity wit their specific synaptic circuitry in the spinal cord. (Korean J Anesthesiol
1995;
29: 329~343)
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