Light adaptation changes both the sensitivity and maximum amplitude (R_max) of the mouse photopic electroretinogram (ERG) b-wave. Using the ERG, we examined how modulation of gap junctional coupling between rod and cones alters the light-adapted ERG. To measure changes, a b-wave light adaptation enhancement factor (LAEF), was defined as the ratio of R_max after 15 min light adaptation to R_max recorded at the onset of an adapting light. For wild-type mice (WT), the LAEF averaged 2.64 ± 0.29, however, it was significantly reduced (1.06 ± 0.04) for connexin 36 knock out (Cx36KO) mice, which lack electrical coupling between photoreceptors. Wild type mice intraocularly injected with meclofenamic acid (MFA), a gap junction blocker, also showed a significantly reduced LAEF. Degeneration of rod photoreceptors significantly alters the effects of light adaptation on the photopic ERG response. Rd10 mice at P21, with large portions of their rod photoreceptors present in the retina, exhibited a similar b-wave enhancement as wildtype controls, with a LAEF of 2.55 ± 0.19. However, by P31 with most of their rod photoreceptors degenerated, rd10 mice had a much reduced b-wave enhancement during light-adaptation (LAEF of 1.54 ± 0.12). Flicker ERG responses showed a higher temporal amplitude in mesopic conditions for WT than those of Cx36KO mice, suggesting rod-cone coupling help high-frequency signals to pass from rods to cone pathways in the retina. In conclusion, our study provides a novel method to noninvasively measure the dynamics and modulation by the light adaptation for rod-cone gap junctional coupling in intact eyes.

光的适应性会改变小鼠明视视网膜电图（ERG）b波的灵敏度和最大振幅（R _max）。使用ERG，我们检查了杆和锥之间的间隙连接耦合的调制如何改变光适应性ERG。为了测量的变化，一个b波光适应增强因子（LAEF），被定义为R的比率_最大15分钟后光适应于R_最大在适应光开始时记录下来。对于野生型小鼠（WT），LAEF平均为2.64±0.29，但是，连接蛋白36基因敲除（Cx36KO）小鼠的LAEF显着降低（1.06±0.04），这在感光器之间缺乏电耦合。眼内注射了甲氯芬那酸（MFA）（一种缝隙连接阻滞剂）的野生型小鼠也表现出明显的LAEF降低。杆感光细胞的变性显着改变了光适应对明视ERG反应的影响。P21处的Rd10小鼠，其杆状感光细胞的大部分存在于视网膜中，与野生型对照表现出相似的b波增强，其LAEF为2.55±0.19。但是，通过P31的大多数杆感光细胞退化，rd10小鼠的光适应过程中的b波增强大大降低（LAEF为1.54±0.12）。与Cx36KO小鼠相比，闪烁的ERG反应在WT的中观条件下显示出更高的时间振幅，这表明杆锥耦合有助于高频信号从杆传递到视网膜中的圆锥通路。总之，我们的研究提供了一种新颖的方法，可以通过光适应性来无损地测量动力学和调制，以用于完整眼中的杆锥间隙连接耦合。