Novelty triggers an increase in orienting behavior that is critical to evaluate the potential salience of unknown events. As novelty becomes familiar upon repeated encounters, this increase in response rapidly habituates as a form of behavioral adaptation underlying goal-directed behaviors. Many neurodevelopmental, psychiatric and neurodegenerative disorders are associated with abnormal responses to novelty and/or familiarity, although the neuronal circuits and cellular/molecular mechanisms underlying these natural behaviors in the healthy brain are largely unknown, as is the maladaptive processes that occur to induce impairment of novelty signaling in diseased brains. In rodents, the development of cutting-edge tools that allow for measurements of real time activity dynamics in selectively identified neuronal ensembles by gene expression signatures is beginning to provide advances in understanding the neural bases of the novelty response. Accumulating evidence indicate that midbrain circuits, the majority of which linked to dopamine transmission, promote exploratory assessments and guide approach/avoidance behaviors to different types of novelty via specific projection sites. The present review article focuses on midbrain circuit analysis relevant to novelty processing and habituation with familiarity.

新颖性引发定向行为的增加，这对于评估未知事件的潜在显着性至关重要。随着新奇事物在反复遇到时变得熟悉，这种反应的增加迅速成为一种行为适应形式，这种形式是目标导向行为的基础。许多神经发育、精神疾病和神经退行性疾病与对新鲜事物和/或熟悉事物的异常反应有关，尽管健康大脑中这些自然行为背后的神经元回路和细胞/分子机制在很大程度上是未知的，而导致损伤的适应不良过程也是如此患病大脑中的新奇信号。在啮齿动物中，允许通过基因表达特征测量选择性识别的神经元集合中的​​实时活动动态的尖端工具的开发开始在理解新奇反应的神经基础方面取得进展。越来越多的证据表明，中脑回路（其中大部分与多巴胺传输有关）促进探索性评估，并通过特定的投射部位将接近/回避行为引导到不同类型的新奇事物。本评论文章侧重于与新奇处理和熟悉熟悉相关的中脑回路分析。通过特定的投影站点促进探索性评估并指导对不同类型新奇事物的接近/回避行为。本评论文章侧重于与新奇处理和熟悉熟悉相关的中脑回路分析。通过特定的投影站点促进探索性评估并指导对不同类型新奇事物的接近/回避行为。本评论文章侧重于与新奇处理和熟悉熟悉相关的中脑回路分析。