Role of intracellular calcium and sodium in light adaptation in the retina of the honey bee drone (Apis mellifera, L).
Role of intracellular calcium and sodium in light adaptation in the retina of the honey bee drone (Apis mellifera, L).
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DOI：
10.1085/jgp.67.4.475
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发表时间：
1976-04
期刊：
影响因子：
--
通讯作者：
Bertrand D
中科院分区：
文献类型：
--
作者：
Bader C;Baumann F;Bertrand D
在蜜蜂实验中，背景光照下视网膜细胞对光敏感性的降低可以通过背景光诱发的初始瞬态去极化和最低稳定去极化的振幅差来准确反映。结果表明，细胞内注射EGTA可以防止光敏度的降低和伴随的电位从瞬态到平稳期的下降。当Ca或Na注射到适应黑暗的视网膜细胞中，而不是K、Li或Mg注射到适应黑暗的视网膜细胞中，也会出现短闪光反应的持续时间和幅度的减少，例如在照明后立即观察到的。将EGTA注射到视网膜细胞中，维持稳定的光适应状态，发现会导致对短测试闪光的反应幅度和持续时间增加，从而产生暗适应效果。这表明，在蜜蜂的视网膜中，细胞内钙浓度的增加在光适应中起着核心作用，而在对光的反应过程中，钠离子的流入导致细胞内钠浓度的增加，可能导致细胞内游离钙的增加。
In the honey bee drone, the decrease in sensitivity to light of a retinula cell exposed to background illumination was found to be accurately reflected by the difference in amplitude between the initial transient depolarization and the lowest steady depolarization evoked by the background light. It is shown that both the decrease in sensitivity to light and the accompanying drop in potential from the transient to the plateau can be prevented by injecting EGTA intracellularly. A decrease in duration and amplitude of responses to short test flashes such as observed immediately after illumination was found to occur too when Ca or Na, but not K, Li, or Mg injected into dark-adapted retinula cells. Injection of EGTA into a retinula cell maintained a steady state of light adaptation, was found to cause an increase in amplitude and duration of the response to a short test flash, thus producing the effects of dark adaptation. It is suggested that, in the retina of the honey bee drone, an increase in intracellular calcium concentration plays a central role in light adaptation and that an increase in intracellular sodium concentration, resulting from the influx of sodium ions during the responses to light, could lead to this increase in intracellular free calcium.