人视皮质17区NPY样免疫反应阳性神经元的形态、分布和发育

MORPHOLOGY,DISTRIBUTION AND DEVELOPMENT OF NEUROPEPTIDE Y-LIKE IMMUNOREACTIVE NEURONS IN HUMAN VISUAL CORTEX BRODMANN 17 AREA

采用免疫细胞化学技术ABC法，以引产死亡胎儿13例和死亡足月产新生儿4例为材料．对其树皮质Brodmann17区NPY样阳性结构进行了观察．发现新生儿视皮质NPY样阳性神经元主要位于灰-白质交界区和浅层白质内．NPY样阳性神经元为非锥体形神经元，以多极和双簇状神经元为主，还有部分双极和不成熟神经元．阳性神经元有大量的突起，在交界区和浅层白质内形成浓密的纤维网，而皮质层内种经纤维相当稀疏．发育学研究显示，胎龄22周已有阳性神经元出现，随着胎龄的增长，阳性神经元的密度、体积、突起的数量和长度不断增长，成熟神经元的比例也逐渐增加，阳性神经元逐渐向皮质迁移．

Immunocytochemical technique (ABC rnethod ) was used to examine the morphology, distribution and development of NPY-like imrnunoreactive neurons in human visual cortex Brodmann 17 area. 13 cases of human fetuses rangingfrom 22- to 34-week-old and 4 cases of neonates were studied. At birth, NPY-like immunoreactive neurons of human visualcortex were principally present at superficial-white matter and border area between gray and white matter. The somatic density is 24 neurons per mm2. Some NPY-ir neurons distributed sparsely in gray matter. They were located within layers Ⅵ,Ⅴ, Ⅲ and Ⅱ, none in layer W and Ⅰ, in the cortex. NPY-ir neurons were shown non-pyramidal form, most of them weremultipolar (55. 44 % ) and bitufted (32. 60% ) neurons, others were bipolar(8. 70%) and immature (3. 26 % ) neurons. NPY-irneurons gave a lot of processes with rich ramification, which formed a rich network in superficial white matter and the borderarea, but there were only a little fibers in gray matter.Development study indicated that NPY-ir neurons was expressed at embryonic 22th week, the majority of these neuronswere located in a narrow area including subplate and lateral part of the intermediate zone, and were bipolar and immatureneurons. Along with the increase of embryonic age, the density, volunm, processes of neurons and percentage of matureneurons increased continuously ， and positive neurons migrated slowly into the cortex plate or cortex, and positive fibers began to present in the cortex. A few NPY-ir neurons presented in layer Ⅴ and Ⅵ at EW34 and in layer Ⅱ and Ⅲ at birth.There were some immature NPY-ir neurons at birth, it suggested that the NPY-ir neurons in the human visual cortex mustundergo through a period of postnatal development to become mature.