Neuropeptide Y and dynorphin-immunoreactive large dense-core vesicles are strategically localized for presynaptic modulation in the hippocampal formation and substantia nigra.
Neuropeptide Y and dynorphin-immunoreactive large dense-core vesicles are strategically localized for presynaptic modulation in the hippocampal formation and substantia nigra.
复制标题
神经肽 Y 和强啡肽免疫反应性大致密核心囊泡战略性地定位于海马结构和黑质的突触前调节。
DOI：
10.1002/syn.890190303
复制
发表时间：
1995
期刊：
影响因子：
--
通讯作者：
Milner,TA
中科院分区：
文献类型：
--
作者：
Pickel,VM;Chan,J;Veznedaroglu,E;Milner,TA
神经肽Y(NPY)和强啡肽分别在海马结构和黑质网状部引起局部选择性突触前调制。我们通过确定大的(80-120 nm)致密核小泡(DCV)的分布和大小来研究它们突触前调制的潜在解剖底物，这些细胞器先前被证明是每个肽的免疫反应性的。在整个海马结构中，NPY免疫反应阳性的DCV主要位于轴突终末，在树突中分布较少。与海马结构的其他部分相比，NPY标记的DCV在CA1区的轴突和终末最为丰富。海马区CA1区的DCV在沿着与未标记轴突接触的终末部分定位时，其平均横截面直径也更大。在海马CA1区和齿状回，NPY标记的DCV与轴突膜上与星形胶质细胞相对的部分接触的DCV也比位于轴突终末中心的DCV大。黑质轴突终末的强啡肽免疫反应的DCV明显较大，当靠近轴索膜的部分不仅与其他轴突和星形细胞突起接触，有时也与突触后树突接触。DCV的直径与已知的NPY在海马CA1区对突触前调制的选择性之间的相似之处表明，免疫反应性DCV的大小和分布与它们的胞吐释放部位之间存在直接的相关性。通过类比，我们可以得出结论，黑质网状部的强啡肽也主要是突触前调节器，但也可能通过与星形胶质细胞或突触后神经元上的感受性部位的相互作用而引起功能变化。
Neuropeptide Y (NPY) and dynorphin elicit regionally selective presynaptic modulation in the hippocampal formation and the pars reticulata of the substantia nigra, respectively. We examined potential anatomical substrates for their presynaptic modulation by determining the distribution and size of large (80–120 nm) dense‐core vesicles (DCVs), organelles previously shown to be immunoreactive for each peptide. Throughout the hippocampal formation, NPY‐immunoreactive DCVs were located primarily in axon terminals and were more sparingly distributed in dendrites. In comparison with other portions of the hippocampal formation, NPY‐labeled DCVs were most abundant in axons and terminals of the CA1 region. The DCVs in the CA1 region of the hippocampus also more frequently had larger mean cross‐sectional diameters when located along portions of the terminal in contact with unlabeled axons. In both the CA1 region of the hippocampus and the dentate gyrus, NPY‐labeled DCVs in contact with portions of the axonal membrane apposed to astrocytes also were larger than those located more centrally in the axon terminal. Dynorphin‐immunoreactive DCVs in axon terminals 'of the substantia nigra were significantly larger when found near portions of the axonal membrane in contact not only with other axons and astrocytic processes, but also occasionally with postsynaptic dendrites. The parallels between diameters of DCVs and known selectivity of NPY for presynaptic modulation in the CA1 region of the hippocampus suggest a direct correlation between the size and distribution of immunoreactive DCVs and their sites of exocytotic release. By analogy, we can conclude that dynorphin in the pars reticulata of the substantia nigra is also principally a presynaptic modulator, but may additionally elicit functional changes through interactions with receptive sites on astrocytes or postsynaptic neurons. © 1995 Wiley‐Liss, Inc.