Montreal Neurological Institute, McGill University, Montreal, QC, H3A 2B4, Canada.
Nat Commun. 2022 Sep 19;13(1):5483. doi: 10.1038/s41467-022-33204-0.
Vision plays a crucial role in instructing the brain's spatial navigation systems. However, little is known about how vision loss affects the neuronal encoding of spatial information. Here, recording from head direction (HD) cells in the anterior dorsal nucleus of the thalamus in mice, we find stable and robust HD tuning in rd1 mice, a model of photoreceptor degeneration, that go blind by approximately one month of age. In contrast, placing sighted animals in darkness significantly impairs HD cell tuning. We find that blind mice use olfactory cues to maintain stable HD tuning and that prior visual experience leads to refined HD cell tuning in blind rd1 adult mice compared to congenitally blind animals. Finally, in the absence of both visual and olfactory cues, the HD attractor network remains intact but the preferred firing direction of HD cells drifts over time. These findings demonstrate flexibility in how the brain uses diverse sensory information to generate a stable directional representation of space.
视觉在指导大脑的空间导航系统方面起着至关重要的作用。然而,对于视觉丧失如何影响空间信息的神经元编码,人们知之甚少。在这里,我们通过记录小鼠丘脑前背核中的头方向(HD)细胞,发现 rd1 小鼠(一种光感受器退化的模型)在大约一个月大时失明,但仍保持稳定和强大的 HD 调谐。相比之下,将有视力的动物置于黑暗中会显著损害 HD 细胞的调谐。我们发现,失明的老鼠利用嗅觉线索来维持稳定的 HD 调谐,并且与先天失明的动物相比,先前的视觉体验会导致盲 rd1 成年老鼠的 HD 细胞调谐更加精细。最后,在没有视觉和嗅觉线索的情况下,HD 吸引子网络仍然完整,但 HD 细胞的首选发射方向会随时间漂移。这些发现表明,大脑在利用各种感官信息生成稳定的空间方向表示方面具有灵活性。