Department of Anatomy and Neuroscience, University College Cork, Ireland.
Department of Anatomy and Neuroscience, University College Cork, Ireland; APC Microbiome Ireland, University College Cork, Ireland.
Neuropharmacology. 2019 Feb;145(Pt A):49-58. doi: 10.1016/j.neuropharm.2018.05.007. Epub 2018 May 14.
Adolescence is a critical period for postnatal brain maturation and a time during which there is increased susceptibility to developing emotional and cognitive-related disorders. Exercise during adulthood has been shown to increase hippocampal plasticity and enhance cognition. However, the impact of exercise initiated in adolescence, on brain and behaviour in adulthood is not yet fully explored or understood. The aim of this study was to compare the impact of voluntary exercise that was initiated either during adolescence or early adulthood on cognitive performance in hippocampal and amygdala-dependent fear conditioning tasks in adulthood. Adult (eight weeks old) and adolescent (four weeks old) male Sprague Dawley rats had access to a running wheel (exercise) or were left undisturbed (sedentary control) for seven weeks. Adult-initiated exercise enhanced both contextual and cued fear conditioning, while conversely, exercise that began in adolescence did not affect performance in these tasks. These behaviours were accompanied by differential expression of plasticity-related genes in the hippocampus and amygdala in adulthood. Specifically, adolescent-initiated exercise increased the expression of an array of plasticity related genes in the hippocampus including BDNF, synaptophysin, Creb, PSD-95, Arc, TLX and DCX, while adult-initiated exercise did not affect hippocampal plasticity related genes. Together results show that exercise initiated during adolescence has a differential effect on hippocampal and amygdala-dependent behaviour and neuronal plasticity compared to when exercise was initiated in adulthood. These findings reinforce adolescence as a period during which environmental influences have a distinct impact on neuronal plasticity and cognition. This article is part of the Special Issue entitled "Neurobiology of Environmental Enrichment".
青春期是大脑后天成熟的关键时期，也是易患情绪和认知相关障碍的时期。成年后进行锻炼已被证明可以增加海马体的可塑性并增强认知能力。但是，青春期开始的锻炼对成年期的大脑和行为的影响尚未得到充分探索或理解。本研究的目的是比较在成年期开始的自愿锻炼对海马体和杏仁核依赖的恐惧条件反射任务中认知表现的影响，这种锻炼分别在青春期或成年早期开始。成年（八周龄）和青春期（四周龄）雄性 Sprague Dawley 大鼠有机会使用跑步轮（运动）或保持安静（久坐对照）七周。成年开始的运动增强了情境和线索恐惧条件反射，而相反，青春期开始的运动则不会影响这些任务的表现。这些行为伴随着成年海马体和杏仁核中与可塑性相关的基因表达的差异。具体而言，青春期开始的运动增加了海马体中一系列与可塑性相关的基因的表达，包括 BDNF、突触小体蛋白、Creb、PSD-95、Arc、TLX 和 DCX，而成年开始的运动则不会影响海马体与可塑性相关的基因。这些结果表明，与成年开始的运动相比，青春期开始的运动对海马体和杏仁核依赖的行为和神经元可塑性有不同的影响。这些发现强调了青春期是环境影响对神经元可塑性和认知产生明显影响的时期。本文是特刊“环境丰富的神经生物学”的一部分。
