토끼 중간뇌 중심회색질에서 Calbindin D28K와 Calretinin 분포상 비교

Abstract

ABSTRACT Comparison of Distribution Patterns between Calbindin-D28K and Calretinin in the Midbrain Periaqueductal Gray in the Rabbit

Jin Lee Advisor: Prof. Sang-Hoon Kim Ph.D. Department of Medicine Graduate School of Chosun University

The periaqueductal gray(PAG), the core structure of the midbrain, plays an important role in coordinating overall defensive reactions including analgesic, autonomic and behavioral responses to stressful stimuli.. In spite of its functional significance, the anatomical subdivisions within the PAG are incompletely elucidated only in the rat, and remains still obscure in other animal species. The present study aims at compartmentalizing the anatomical territory of the rabbit PAG, based on the distribution patterns of several neurochemical markers. Immunohistochemistry for calbindin-D28K(CB) and calretinin(CR) and histochemistry for NADPH-diaphorase(NADPHd), cytochrome oxidase (CO), and acetylcholinesterase (AChE) were carried out in consecutive midbrain slices of the rabbit. Double staining and immunofluorescent labeling for selected markers were additionally performed. Each neurochemical marker revealed its unique distribution pattern, demonstrating restricted subregions within the PAG and their locational changes according to the rostrocaudal levels. CB-immunoreactive(CB-ir) perikarya and nerve endings were observed as clustered in the ventral halves of lateral(L) and ventrolateral(VL) longitudinal columns at the caudal, and the medial half of dorsolateral(DL) column throuout the longitudinal level. Clusters of CB-ir perikarya also marked supraoculomotor cap nucleus(Su3C) at the longitudinally intermediate level, and rostrodorsal nucleus(RD) at the rostral level of the PAG. Calretinin-immunoreactive(CR-ir) perikarya clustered in the dorsal half of VL at the caudal, supratrochlear nucleus(Su4) at the intermediate, and the medial half of DL throughout the levels. Dense network of NADPHd-positive perikarya and axons marked the whole territory of DL throughout the level, dorsal half of VL at the caudal, Su3C and DL at the intermediate level. Double labeling revealed that NADPHd-positive neurons belonged to different cell group from CB- or CR-ir ones. CO-reactive area coincided with CB-poor subdivisions; dorsomedial(DM) and L columns. AChE-positive areas were L at the caudal, DM, and the wedge-shaped lateral corner of DL at the intermediate level. These finding suggest that the territory of the PAG could be subdivided into compartments on the neurochemical basis further than the four longitudinal cell columns of the current concept, and that CB and CR as well as NADPHd are appropriate markers for several anatomical nuclei within the PAG. _____________________________________________________________________________ Key Words: Periaqueductal gray, Longitudinal cell columns, Calbindin, Calretinin, NADPH-diaphorase, Acetylcholinesterase, Cytochrome oxidase.