Habituation is a non-associative form of learning characterized by a decremented response to repeated stimulation. It is typically framed as a process of selective attention, allowing animals to ignore irrelevant stimuli in order to free up limited cognitive resources. However, habituation can also occur to threatening and toxic stimuli, suggesting that habituation may serve other functions. Here we took advantage of a high-throughput Caenorhabditis elegans learning assay to investigate habituation to noxious stimuli. Using real-time computer vision software for automated behavioral tracking and optogenetics for controlled activation of a polymodal nociceptor, ASH, we found that neuropeptides mediated habituation and performed an RNAi screen to identify candidate receptors. Through subsequent mutant analysis and cell-type-specific gene expression, we found that pigment-dispersing factor (PDF) neuropeptides function redundantly to promote habituation via PDFR-1-mediated cAMP signaling in both neurons and muscles. Behavioral analysis during learning acquisition suggests that response habituation and sensitization of locomotion are parts of a shifting behavioral strategy orchestrated by pigment dispersing factor signaling to promote dispersal away from repeated aversive stimuli.

习惯是一种非关联性的学习形式，其特征是对重复刺激的反应减少。它通常被设计为选择性注意的过程，允许动物忽略无关的刺激，以释放有限的认知资源。然而，习惯性也可能发生于威胁性和毒性刺激，这表明习惯性可能还起到其他作用。在这里，我们利用了高通量秀丽隐杆线虫的优势学习测定法研究有害刺激的习惯性。使用实时计算机视觉软件进行自动的行为跟踪和光遗传学，以控制多式联运伤害感受器ASH的激活，我们发现神经肽介导了习性并进行了RNAi筛选以识别候选受体。通过随后的突变分析和细胞类型特异性基因表达，我们发现色素分散因子（PDF）神经肽冗余地通过PDFR-1介导的cAMP信号在神经元和肌肉中促进习惯化。学习习得过程中的行为分析表明，反应习惯和运动敏感性是由颜料分散因子信号传递来促使分散远离重复厌恶刺激而改变的行为策略的一部分。