Zhu B S, Gibbins I
Department of Anatomy and Histology, School of Medicine, Flinders University of South Australia, Adelaide, Australia.
Vis Neurosci. 1995 Sep-Oct;12(5):919-27. doi: 10.1017/s0952523800009470.
Synaptic connections of amacrine cells with substance P-like or neuropeptide Y-like immunoreactivity (SP-LI or NPY-LI) in the retina of the cane toad, Bufo marinus, were investigated using ultrastructural immunocytochemistry. The perikarya of SP-LI or NPY-LI amacrine cells were located in the innermost row of the inner nuclear layer. The synapses associated with SP-LI amacrine cells were distributed mainly in sublaminae 3 and 4 with about 10% in sublamina 1 of the inner plexiform layer. The synapses formed by NPY-LI amacrine cells were found in sublaminae 1, 2, and 4 with approximately equal frequency. Of a total of 175 SP-LI profiles, 56% were in presynaptic positions and 44% in postsynaptic positions. The synaptic inputs to SP-LI profiles predominantly derived from other unlabeled amacrine cell dendrites, and to a lesser extent, from bipolar cell terminals. The majority of synaptic outputs from SP-LI amacrine cell dendrites were directed onto unlabeled amacrine cell processes. The SP-LI profiles also made synapses onto bipolar cell terminals and formed synapses onto presumed ganglion cell dendrites. Of a total of 200 NPY-LI profiles, 48% were in presynaptic positions and 52% in postsynaptic positions. The profiles of NPY-LI amacrine cells mainly received their synaptic inputs from other unlabeled amacrine cell processes, and to a lesser extent, from bipolar cell terminals. The majority of NPY-LI amacrine cell profiles gave their synaptic outputs onto unlabeled amacrine cell dendrites, and others formed synapses onto presumed ganglion cell processes. These results suggest that these two populations of neuropeptide-containing amacrine cells in the Bufo retina are involved in different synaptic circuits.
利用超微结构免疫细胞化学技术，研究了海蟾蜍（Bufo marinus）视网膜中具有P物质样或神经肽Y样免疫反应性（SP-LI或NPY-LI）的无长突细胞的突触连接。SP-LI或NPY-LI无长突细胞的胞体位于内核层的最内层。与SP-LI无长突细胞相关的突触主要分布在内网状层的第3和第4亚层，约10%分布在第1亚层。NPY-LI无长突细胞形成的突触在第1、2和4亚层中出现的频率大致相等。在总共175个SP-LI形态中，56%处于突触前位置，44%处于突触后位置。SP-LI形态的突触输入主要来自其他未标记的无长突细胞树突，其次来自双极细胞终末。SP-LI无长突细胞树突的大多数突触输出指向未标记的无长突细胞突起。SP-LI形态也与双极细胞终末形成突触，并与假定的神经节细胞树突形成突触。在总共200个NPY-LI形态中，48%处于突触前位置，52%处于突触后位置。NPY-LI无长突细胞的形态主要从其他未标记的无长突细胞突起接收突触输入，其次来自双极细胞终末。大多数NPY-LI无长突细胞形态将其突触输出到未标记的无长突细胞树突上，其他的则与假定的神经节细胞突起形成突触。这些结果表明，海蟾蜍视网膜中这两种含神经肽的无长突细胞群体参与了不同的突触回路。
