Immunoelectron microscopy of vasotocin neurons in the chicken hypothalamu

用免疫组织化学技术对家鸡的血管催产素(VT)免疫反应(Ir)神经元进行了研究。在下丘脑视前区和脑室周围区域有多个VT-ir细胞群。胞体大小为22-25x15微米。形状因子为0.7-0.8。在视前区，VT-ir胞体恰好分布在软脑膜下。在脑室周围区域，有许多VT-ir突起和胞体。其中一些免疫反应纤维显然起源于室管膜下区的每个免疫反应胞体。这些走向第三脑室的免疫反应突起似乎到达了室管膜细胞层。这些突起似乎是室管膜下区免疫反应神经元的树突。P-1区VT-ir神经元的免疫电子显微镜(Berk等人。1982)揭示了与第三脑室室管膜细胞基本成分接触的VT-ir突起。在这些VT-ir突起上，发现有免疫阴性终末。在P-1区室管膜下神经膜内，可见许多大小不等的免疫反应突起。免疫阳性突起上常可见含有透明小泡的免疫阳性突触终末。室管膜细胞的连接复合体看起来缺乏紧密连接。神经肽Y(NPY)的免疫电子显微镜显示在P-1区有许多NPY-ir突起和终末样构筑。至少两种类型的NPY-Ir过程。首先，有些突起是轴突纤维。第二类进程属于终端。末端状结构直径为725-750 nm。NPY阳性轴突终末经常与免疫阳性树突接触。这些结果表明，P-1区的VT-ir神经元接受NPY投射。还需要进一步的研究来证实该区域在家鸡中的预测。

Vasotocin(VT)- immunoreactive(ir) neurons of the domestic chicken were studied by an immunohistochemical technique.There are several VT-ir cell populations in the preoptic areas and periventricular regions of the hypothalamus. The sizes of these cell bodies are 22-25X15mum. Shape factors are 0.7-0.8. In preoptic areas VT-ir cell bodies are distributed just under a pia mater. In the periventricular region, there are many VT-ir processes and somata. Some of these immunoreactive fibers apparently originate in each of the immunoreactive somata in the subependymal zone. Thich immunoreactive processes running toward the third ventricle seem to reach the ependymal cell layr. These processes seem to be dendritic processes of immunoreactive neurons located in the subependymal region.Immunoelectron microscopy of VT-ir neurons of the P-1 region(Berk et al. 1982)revealed VT-ir processes that make contact with the basal elements of ependymal cells of the third ventricle. On these VT-ir processes, immunonegative terminals are found. In the subependymal neuropil of the P-1 region, many immunoreactive processes of various sizes are found. Immunonegative synaptic terminals containing clear vesicles were frequently observed on thin immunopositive processes. The junctional comlex of ependymal cells seemes to lack a tight junction.Immunoelectron microscopy of neuropeptide Y(NPY) revealed that there are many NPY-ir processes and terminal like formations in the P-1 region. At least two types of NPY-ir processes. First, some of precesses are axonal fibers. Second type of processes belongs to terminals. Terminal-like structures are 725-750nm in diameter. NPY-ir axonal terminals frequently contact with immunonegative dendrites in this region. These results suggest that VT-ir neurons of P-1 region receive a NPY projection. Further studies are needed to confirm the NPY projection of this region in the domestic chicken.