Training-induced restoration of topographic maps and vision during opticnerve regeneration

成熟的大脑和脊髓，或中枢神经系统（CNS），是极其复杂的。这种复杂性的后果是，在损伤后几乎没有自发的修复或再生。因此，脑损伤和截瘫或四肢瘫痪给个人和社会造成了极高的成本，据估计，澳大利亚每年的成本约为10亿美元。因此，最大的医学挑战之一是神经损伤后的功能恢复。然而，在过去十年中，最令人兴奋的进步之一是认识到成人中枢神经系统，特别是在受损后，确实具有修复能力，并且通过相关经验或特定训练产生的适当神经活动，在驱动修复过程中至关重要，从而产生有用的行为恢复。一个最明显的例子来自我们的实验室，我们最近表明，在视神经再生期间训练动物进行特定的视觉任务可以恢复有用的视力；未经训练的动物通过实验眼是看不见的。视觉系统的优势在于，它是中枢神经系统中相对简单的一部分，只有一类主要的神经细胞投射到明确的、可接近的大脑区域。该项目的意义在于，我们第一次能够在已识别的神经细胞及其连接中精确定位特定的训练诱导效应，而在其他中枢神经系统区域中，这一任务要困难得多。特别是，我们将研究通过训练诱导的分子，解剖和功能变化，并探索是否使用抑制性神经传递阻滞剂干预进一步提高训练的有益效果。了解神经损伤后训练的积极作用背后的神经细胞的变化，将对中枢神经系统损伤后改善恢复的康复策略的持续发展产生影响。

The mature brain and spinal cord, or central nervous system (CNS), are extremely complex. A consequence of such complexity is that little if any spontaneous repair or regeneration occurs after damage. Brain injury and para- or quadriplegia thus inflict extremely high costs on the individual and to society, estimated at approximately $1 billion annually in Australia. One of the greatest medical challenges therefore is to restore function following neurotrauma. One of the most exciting advances, however, over the last decade is the recognition that the adult CNS, particularly after damage, does have a capacity for repair and that appropriate neural activity, produced either via relevant experience or specific training, is essential in driving the repair process to produce useful behavioural recovery. One of the clearest examples comes from our laboratory in which we have recently shown that training animals on specific visual tasks during optic nerve regeneration allows useful vision to be restored; untrained animals are blind via the experimental eye. The advantage of the visual system is that it is a relatively simple part of the CNS with one major class of nerve cell projecting to well defined and accessible brain regions. The significance of the project is that, for the first time, we are able pinpoint specific training-induced effects within identified nerve cells and their connections, a task that is much harder within other CNS regions. In particular, we will examine molecular, anatomical and functional changes that are induced via training and explore whether intervention with blockers of inhibitory neurotransmission further improves the beneficial effects of training. Understanding the changes in nerve cells that underlie the positive effects of training after neurotrauma will have implications for the continuing development of rehabilitation strategies for improved recovery after CNS injury.