鸵鸟雏鸟下丘脑室旁核发育的组织学及GABA的表达

【目的】观察鸵鸟雏鸟下丘脑室旁核（paraventricular hypothalamic nucleus，PVN）的显微结构和细胞凋亡的发育特点，探明γ-氨基丁酸（γ-aminobutyric，GABA）阳性细胞在PVN内的年龄增长性变化。【方法】以1、45和90 d健康非洲鸵鸟雏鸟为实验动物，利用H.E染色技术、原位缺口末端标记（TUNEL）技术和免疫组化定位表达（SABC）技术，研究鸵鸟雏鸟下丘脑PVN的发育特点。【结果】①鸵鸟雏鸟下丘脑PVN的组织学结构随日龄的增长而逐渐发育成熟，其中PVN小细胞占细胞总数的比例在45 d时最低，明显高于1和90 d的小细胞核；②鸵鸟雏鸟下丘脑PVN内存在细胞凋亡现象，凋亡呈年龄增长性减少；③鸵鸟雏鸟下丘脑PVN内可检测到GABA阳性产物，表达量呈年龄增长性增加的趋势，其中 PVN大细胞部（mPVN）和小细胞部（pPVN）的平均积分光密度均在45 d时最高，显著高于1和90 d的（P＜0.01）。【结论】随着日龄的增长，鸵鸟雏鸟下丘脑PVN的结构和功能不断完善，其在出生后早期（1—45 d）发育较快。

Histological Observation and Expression Patterns of GABA in Development of Ostrich Chicks' Paraventricular Hypothalamic Nucleus

【Objective】The experiment was conducted to study the development characteristics of the microstructure and apoptosis in paraventricular hypothalamic nucleus(PVN) of ostrich chicks.The Age-related change of γ-aminobutyric acid(GABA) positive cells was also investigated.【Method】One,45 and 90 d healthy ostrich chicks were selected from a normal group.The development characteristics of PVN in ostrich chicks was detailly observed by HE staining,terminal deoxynucleotidyl transferase-mediated(TUNEL) and immunohistochemistry(SABC).【Result】 The results showed that the histological structure of PVN developed maturity gradually with the ages of ostrich chicks.The cell proportion of parvocellular PVN was the on lowest on 45 d than that on 1 d and 90 d.A less number and an age-related decline of apoptosis in PVN could be found.The positive signals of GABA positive cells could be detected in PVN,with the expression increased with age growing of ostrich chicks,and the average optical density of magnocellular paraventricular nucleus(mPVN) and parvocellular paraventricular nucleus(pPVN) reached the maximum on 45 d(P<0.01).【Conclusion】These results demonstrate that the structure and function of PVN in ostrich chicks is under continuous perfection and development,especially in early postnatal period(1-45 d).