Applied Microscopy

Korean Society of Microscopy (한국현미경학회)
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Zinc-enriched (ZEN) Terminals in Onuf's Nucleus Innervating External Urethral Sphincter: HRP Tracing Method and Zinc Selenium Autometallography

바깥요도조임근을 지배하는 Onuf 핵에서 관찰된 Zinc 함유 신경종말: HRP 추적법 및 zinc selenium 조직화학법

  • Lee, Bo-Ye (Department of Anatomy, Gachon Medical School) ;
  • Kim, Yi-Suk (Department of Anatomy, Gachon Medical School) ;
  • Lee, Boeb-Y. (Department of Anatomy, College of Medicine, Konkuk University) ;
  • Lee, Hyun-Sook (Department of Anatomy, College of Medicine, Konkuk University) ;
  • Tak, Gye-Rae (Division of Biomedical Engineering, College of Medicine, Konkuk University) ;
  • Lee, Young-Il (Department of Anatomy, College of Medicine, Dankook University) ;
  • Lee, Jeoug-Yeol (Graduate School, College of Medicine, Hallym University) ;
  • Jo, Seung-Mook (Department of Anatomy, Gachon Medical School)
  • 이보예 (가천의과대학교 해부학과) ;
  • 김이석 (가천의과대학교 해부학과) ;
  • 이법이 (건국대학교 의과대학 해부학교실) ;
  • 이현숙 (건국대학교 의과대학 해부학교실) ;
  • 탁계래 (건국대학교 의료생명대학 의학공학부) ;
  • 이영일 (단국대학교 의과대학 해부학교실) ;
  • 이정열 (한림대학교 의과대학 대학원) ;
  • 조승묵 (가천의과대학교 해부학과)
  • Published : 2006.12.31
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Abstract

Onuf's nucleus, which is located in the ventral horn, has been known to innervate the striated muscles of the urethral and anal sphincter muscles via the pudendal nerve Onuf's nuclei are resistant to pathologic condition such as poliovirus. The reason why the motor neurons in Onuf's nucleus are less degenerated is not certain until now. The present study aims at updating the microscopical characteristics including its location the Onuf's nucleus innervating the external urethral sphincter, and ultrastructures of the zinc-enriched (ZEN) terminals synaptically-contacting with Onuf's motor neurons in the rat spinal gray matter by using HRP tracing method and zinc selenium autometallography, respectively. Based on HRP tracing method, Onuf's nuclei were located adjacent lateral dendritic projections of the ventral horn. Their shape was almost round at lumbar level, but oval at sacral segment of spinal cord. In size, their somata were smaller than that of other motor nuclei. In AMG stained sections, Onuf's nuclei were innervated by highly concentrated ZEN terminals, and contained small and middle-sized ZEN, but totally void of large ZEN terminals. AMG silver grains were confined to presynaptic ZEN terminals against dendritic elements and somata of the Onuf's motor neurons. A majority of the ZEN terminals contained flattened synaptic vesicles and made symmetrical synaptic specializations.

Onuf 핵이란 척수 앞회색질뿔에 위치하는 운동핵으로 음부신경을 통해 방광과 항문괄약근을 조절하는 운동핵의 하나이다. Onuf핵은 앞회색질뿔내 다른 운동신경핵과는 달리 회색질척수염과 같은 병적인 상황에서도 상당기간 손상되지 않고 기능을 유지하며, 퇴행성변화의 정도가 미약한데 정확한 원인에 관해서는 논란의 여지가 많다. 본 연구는 흰쥐 척수회색질내 바깥요도조임근을 신경지배하는 Onuf핵의 위치를 HRP 추적법으로 확인하였으며, 이들 신경핵내 운동신경세포와 연접해 있는 zinc함유(ZEN)신경종말의 미세구조를 zinc selenium조직화학법(AMG)으로 염색하여 관찰하였다. HRP 추적법의 결과로는, Onuf핵은 랫드 척수회색질앞뿔의 내측에서 가지돌기의 무리와 거의 맞닿고 있었으며, 모양은 대개 구형 또는 난원형을 띠었다. 이들 신경핵내 운동신경세포의 세포체의 크기는 다른 운동핵의 신경세포보다 다소 작았다. 한편 AMG로 염색한 표본에서는 Onuf핵에 분포하는 ZEN신경종말은 다른 운동핵의 ZEN 신경종말과 비교하여 매우 높은 밀집도를 보였으나, 크기 면에서도 상대적으로 작았다. 미세구조 관찰로는 Onuf 핵내 ZEN신경종말은 운동핵의 세포체 및 가지돌기와 신경연접은 이루고 있었다. 이들 ZEN 신경종말은 주로 납작한 연접소포를 함유하였으며, 대칭적인 신경연접구조를 이루고 있었다.

Keywords

References

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