Department of Neurobiology and Anatomy, University of Texas Medical School at Houston, Houston, TX 77225, USA.
Neurochem Res. 2011 Apr;36(4):645-54. doi: 10.1007/s11064-010-0278-0. Epub 2010 Sep 28.
Using immunofluorescence, we showed that histamine receptor 1 is expressed by horizontal cell axons and a subset of amacrine cells in the tiger salamander retina. The effects of histamine on light responses of amacrine cells were studied in slice preparations. Histamine modulated the light responses of many salamander amacrine cells, depending upon the morphological type. The most pronounced effects of histamine were decreases in the light responses of broadly stratified amacrine cells, particularly those having medium-sized dendritic field diameters. To determine whether the effects of histamine were direct, Co(++) was substituted for Ca(++) in the extracellular medium to block synaptic transmission. Histamine still affected broadly stratified amacrine cells, but not narrowly stratified amacrine cells under these conditions. Taken together, these findings suggest that inhibitory interactions between strata of the IPL and within the classical receptive fields of the ganglion cells would be particularly sensitive to histamine released from retinopetal axons.
使用免疫荧光染色，我们发现组胺受体 1 表达在虎纹蝾螈视网膜的水平细胞轴突和一部分无长突细胞中。我们在切片标本上研究了组胺对无长突细胞光反应的影响。组胺可以根据形态类型调制许多蝾螈无长突细胞的光反应。组胺最显著的作用是减少广泛分层无长突细胞的光反应，特别是那些具有中等大小树突场直径的细胞。为了确定组胺的作用是否是直接的，我们在细胞外液中用 Co(++)替代 Ca(++)以阻断突触传递。在这些条件下，组胺仍然影响广泛分层的无长突细胞，但不影响狭窄分层的无长突细胞。总的来说，这些发现表明，IPL 层之间以及节细胞经典感受野内的抑制性相互作用对来自视网膜神经纤维的组胺释放会特别敏感。
