INRIA Biovision Team, Université Côte d'Azur, Valbonne, France.
Institute for Modeling in Neuroscience and Cognition (NeuroMod), Université Côte d'Azur, Nice, France.
Nat Commun. 2024 Jul 20;15(1):6118. doi: 10.1038/s41467-024-50506-7.
A fundamental task for the brain is to generate predictions of future sensory inputs, and signal errors in these predictions. Many neurons have been shown to signal omitted stimuli during periodic stimulation, even in the retina. However, the mechanisms of this error signaling are unclear. Here we show that depressing inhibitory synapses shape the timing of the response to an omitted stimulus in the retina. While ganglion cells, the retinal output, responded to an omitted flash with a constant latency over many frequencies of the flash sequence, we found that this was not the case once inhibition was blocked. We built a simple circuit model and showed that depressing inhibitory synapses were a necessary component to reproduce our experimental findings. A new prediction of our model is that the accuracy of the constant latency requires a sufficient amount of flashes in the stimulus, which we could confirm experimentally. Depressing inhibitory synapses could thus be a key component to generate the predictive responses observed in the retina, and potentially in many brain areas.
大脑的一个基本任务是生成对未来感觉输入的预测，并对这些预测中的错误进行信号传递。许多神经元已经被证明在周期性刺激期间会对缺失的刺激发出信号，即使在视网膜中也是如此。然而，这种错误信号传递的机制尚不清楚。在这里，我们表明，抑制性突触的压抑可以塑造视网膜中对缺失刺激的反应时间。虽然神经节细胞是视网膜的输出，对缺失的闪光在闪光序列的许多频率下以恒定的潜伏期做出反应，但我们发现，一旦抑制被阻断，情况就不是这样了。我们建立了一个简单的电路模型，并表明压抑抑制性突触是重现我们实验结果的必要组成部分。我们的模型的一个新预测是，恒定潜伏期的准确性需要刺激中有足够数量的闪光，这一点我们可以通过实验来证实。因此，压抑抑制性突触可能是在视网膜中观察到的预测性反应的关键组成部分，并且可能在许多大脑区域中也是如此。
