急性低氧对鲫鱼视网膜视杆和视锥信号的不同影响

DIFFERENTIAL EFFECTS OF ACUTE HYPOXIA ON ROD AND CONE SIGNAL TRANSMISSION IN CARP RETINA IN VIVO

在保持完整血液循环的鲫鱼眼杯标本上，应用Ａｇ－ＡｇＣｌ电极记录视网膜电图（ＥＲＧ），研究了急性低氧下不同适应状态ＥＲＧ反应变化的情况，以期分析视锥与视杆通路对急性低氧的敏感性是否不同。结果表明：１．急性低氧对明视ＥＲＧ－ｂ波的影响要远远快于对暗视ｂ波的影响，这说明视锥信号通路比视杆信号通路对缺氧敏感；２．在间视状态下，ＥＲＧ的ｂ波在低氧开始后几分钟内有一个明显的增大过程，而在明视或暗视中皆未观察到，这可能与视杆与视锥信号间的相互作用有关。

To determine how responses of rod signals and cone signals were affected by acute hypoxia,electroretinograms(ERG)were monitored in carp retina in vivo during hypoxic challenge inducedby cutting off the aerated water irrigating the fish gills.The results were as follows:1.Hypoxia af-fected ERG b waves much more quickly in photopic conditions than in scotopic conditions.This indicated that signal transmission from cones are more sensitive and are more severely sup-pressed by hypoxic challenge than rod signal transmission.2.In mesopic conditions the b wavedecline produced by hypoxia was preceded by an initial and temporary enhancement,whichmight be a result of rod-cone interaction.