Can the natural environment enhance developmental plasticity and adult adaptive behavior? Effects of naturalistic rearing environment on gene expression, adult brain organization, and behavior.

项目摘要 新大脑皮层是哺乳动物特有的特征，它有助于深刻的行为灵活性。其中的一部分 灵活性来自早期感觉和运动经验塑造新大脑皮层的能力， 允许有机体调整其感官系统以适应环境的具体问题和机会 它就是在那里长大的。这种发育可塑性允许动物随后产生适应行为， 在其整个生命周期内最好地满足其环境的变化需求。很早就已经确定了 感觉体验可以改变大脑皮层区域内的感觉或运动表征(皮质地图)、神经 反应特性，以及皮质和皮质下的连通性。然而，大多数研究都操纵了一种 在必然是非常受控和受限的环境中进行特定的刺激。此外，目前尚不清楚 如果给定环境(受限或高度可变)的动态性质的差异是导致 发育早期的大脑/行为改变，或者高度动态的环境可以增加能力 以进一步改变成年人的行为。在当前的计划中，我们利用UC的独特资源 戴维斯-田野围栏位于我们的河岸保护区，其大小是标准实验室笼子的3000倍。 这些田野围栏提供了一个高度丰富和充满活力的半自然环境，可以在其中饲养老鼠。我们会 量化半自然和实验室环境之间的触觉自然场景统计数据，使我们能够 量化两种养育刺激条件之间的差异，并随后测试每组 两组动物在发育过程中都经历了全套刺激。的多个功能 我们将比较实验大鼠和人工饲养的大鼠的大脑组织、基因表达和行为。 这些半自然的、高度丰富的条件。虽然这种半自然饲养可能会影响许多基因， 行为和大脑区域，我们关注与皮质发育、区域边界相关的基因 形成，和可塑性。我们将对发育中的动物进行采样，以量化基因表达在 关键时期，并将这种表达与相同队列(小个体)的成年表现联系起来 成年人需要感觉运动整合和协调的行为。我们将进一步量化神经 初级体感皮质(S1)的表型，研究体感，感受野形状，以及 皮质-皮质和皮质-丘脑的连接。我们认为这种模式将受到极大的影响，因为 野外围栏中可用的大空间将促进导航和社交活动的主动触觉探索 互动。这是第一项研究，调查早期接触丰富的自然刺激和 在自然环境中发生的极大增加的运动选择会影响基因表达、神经 表型和行为。

Project Summary The neocortex is a uniquely mammalian feature, one which facilitates profound behavioral flexibility. Part of this flexibility comes from the capacity of the neocortex to be shaped by early sensory and motor experience, allowing the organism to tune its sensory system to the specific problems and opportunities of the environment in which it is reared. This developmental plasticity allows an animal to then generate adaptive behavior that best meets the variable demands of its environment throughout its life. It has been well established that early sensory experience can alter the sensory or motor representation within a cortical field (cortical maps), neural response properties, and cortical and subcortical connectivity. However, most studies manipulate one particular stimulus in what are necessarily very controlled and restricted environments. Further, it is not known if the differences in the dynamic nature of a given environment (restricted or highly variable) are responsible for brain/behavior alterations early in development, or if a highly dynamic environment can increase the capacity for further change in adult behavior. In the current proposal, we take advantage of a unique resource at UC Davis – field pens located on our Riparian Reserve that are 3,000 times the size of a standard laboratory cage. These field pens provide a highly enriched and dynamic semi-natural environment in which to rear rats. We will quantify tactile natural scene statistics between the semi-natural and laboratory environments, allowing us to quantify differences between the two rearing stimulus conditions, and to subsequently test each group of animals with the full set of stimuli that both groups experienced during development. A number of features of brain organization, gene expression, and behavior will be compared between laboratory rats and rats reared in these semi-natural, highly enriched conditions. While this semi-natural rearing may affect numerous genes, behaviors, and brain regions, we focus on genes associated with cortical development, areal boundary formation, and plasticity. We will sample developing animals to quantify changes in gene expression during critical periods, and relate this expression to adult performance from the same cohort (litttermates) on behaviors that require sensorimotor integration and coordination in adults. We will further quantify neural phenotypes of primary somatosensory cortex (S1), investigating somatotopy, receptive field shape, and cortico-cortical and cortico-thalamic connections. We believe this modality will be highly impacted because the large space available in the field pens will promote active tactile exploration for navigation and social interaction. This is the first study that investigates how early exposure to the rich array of natural stimuli and vastly increased movement options occurring in a natural environment impacts gene expression, neural phenotypes, and behavior.