Rhodopsin S334ter-3 retinal degeneration rats have been widely used to investigate degenerative diseases of the retina. In this model, morphological and electrophysiological changes have been observed in the retina, superior colliculus and primary visual cortex (V1). However, no study so far has examined rhodopsin S334ter-3 rats with regards to their contrast response in V1 — a fundamental property of visual information processing. In this study, experimental rats (S334ter-3) carried one copy of the mutant transgene. We compared responses to spatio-temporal variations in luminance contrast in the primary visual cortex of these rats with those in Long-Evans (LE) rats to elucidate the degeneration-specific activity changes in this part of the visual pathway. We measured extracellular responses to different stimulus contrasts at the preferred parameters of each recorded cell under classical receptive field (CRF) stimulation. Our results show that V1 cells in the S334ter-3 group exhibit stronger spontaneous activity but weaker stimulus-evoked responses at medium and high contrasts. By fitting responses to a sigmoid function, we found that the S334ter-3 group had a lower R_max but a larger exponent N than the LE group. However, we did not find a significant difference in C₅₀ value. These results indicate the decrease in discriminating the stimuli contrast and loss in responses and lower signal to noise ratio after retinal degeneration. Our study supports the notion that a considerable degree of plasticity is found in cortex after retinal degeneration, indicating that visual restoration therapies would succeed if the retina could send useful signals to the brain.

视紫红质 S334ter-3 视网膜变性大鼠已被广泛用于研究视网膜的退行性疾病。在该模型中，在视网膜、上丘和初级视觉皮层 (V1) 中观察到形态学和电生理学变化。然而，到目前为止，还没有研究检查视紫红质 S334ter-3 大鼠在 V1 中的对比反应——视觉信息处理的一个基本特性。在这项研究中，实验大鼠 (S334ter-3) 携带了一份突变转基因。我们比较了这些大鼠与 Long-Evans (LE) 大鼠初级视觉皮层亮度对比度时空变化的反应，以阐明这部分视觉通路的退化特异性活动变化。我们测量了在经典感受野 (CRF) 刺激下每个记录细胞的首选参数对不同刺激对比的细胞外反应。我们的结果表明，S334ter-3 组中的 V1 细胞在中高对比度下表现出更强的自发活动但较弱的刺激诱发反应。通过拟合 sigmoid 函数的响应，我们发现 S334ter-3 组具有较低的R _max但比 LE 组更大的指数N。然而，我们没有发现C ₅₀值有显着差异。这些结果表明区分刺激对比度和反应损失的减少以及视网膜变性后信噪比的降低。我们的研究支持这样一种观点，即在视网膜变性后在皮层中发现了相当程度的可塑性，这表明如果视网膜可以向大脑发送有用的信号，视觉恢复疗法就会成功。