Toyoda J I, Saito T, Kondo H
J Comp Neurol. 1978 Jun 1;179(3):569-79. doi: 10.1002/cne.901790308.
Histological and electrophysiological features of horizontal cells were studied in the stingray retina in which the ratio of rods to cones was about five to one. There were three distinct sublayers of horizontal cells; external, middle and internal. The type of horizontal cells recorded was identified by dye injection after recording. Relatively thick external horizontal cells sent their short dendrites into both rod and cone terminals to make synaptic contacts. The response recorded from them was not color-coded but showed a Purkinje shift depending on the adaptational state. Middle horizontal cells were flat and usually two or three of them overlying each other constituted the middle sublayer. Their response, which was difficult to record in the light-adapted retina, was characterized by a slow time course, a prolongation of the response to bright flashes and a maximum sensitivity in the green region of the spectrum without any sign of Purkinje shift. Internal horizontal cells were color-coded. They responded with hyperpolarization at shorter wavelengths and with depolarization at longer wavelengths. It was concluded that the internal horizontal cells receive inputs from cones and the middle horizontal cells from rods, whereas the external horizontal cells receive inputs from both rods and cones.
在棒状细胞与锥状细胞比例约为五比一的魟鱼视网膜中，对水平细胞的组织学和电生理特征进行了研究。水平细胞有三个不同的亚层：外层、中层和内层。记录后通过染料注射来识别所记录的水平细胞类型。相对较粗的外层水平细胞将其短树突发送到棒状细胞和锥状细胞终末以形成突触联系。从它们记录到的反应没有颜色编码，但根据适应状态显示出浦肯野位移。中层水平细胞是扁平的，通常两三个相互叠加构成中层亚层。它们的反应在光适应视网膜中很难记录，其特征是时间进程缓慢、对明亮闪光的反应延长以及在光谱的绿色区域具有最大敏感性，且没有任何浦肯野位移的迹象。内层水平细胞有颜色编码。它们在较短波长下以超极化反应，在较长波长下以去极化反应。得出的结论是，内层水平细胞接收来自锥状细胞的输入，中层水平细胞接收来自棒状细胞的输入，而外层水平细胞接收来自棒状细胞和锥状细胞的输入。
