Age‐dependent cognitive and behavioral deterioration may arise from defects in different components of the nervous system, including those of neurons, synapses, glial cells, or a combination of them. We find that AFD, the primary thermosensory neuron of Caenorhabditis elegans, in aged animals is characterized by loss of sensory ending integrity, including reduced actin‐based microvilli abundance and aggregation of thermosensory guanylyl cyclases. At the functional level, AFD neurons in aged animals are hypersensitive to high temperatures and show sustained sensory‐evoked calcium dynamics, resulting in a prolonged operating range. At the behavioral level, senescent animals display cryophilic behaviors that remain plastic to acute temperature changes. Excessive cyclase activity of the AFD‐specific guanylyl cyclase, GCY‐8, is associated with developmental defects in AFD sensory ending and cryophilic behavior. Surprisingly, loss of the GCY‐8 cyclase domain reduces these age‐dependent morphological and behavioral changes, while a prolonged AFD operating range still exists in gcy‐8 animals. The lack of apparent correlation between age‐dependent changes in the morphology or stimuli‐evoked response properties of primary sensory neurons and those in related behaviors highlights the importance of quantitative analyses of aging features when interpreting age‐related changes at structural and functional levels. Our work identifies aging hallmarks in AFD receptive ending, temperature‐evoked AFD responses, and experience‐based thermotaxis behavior, which serve as a foundation to further elucidate the neural basis of cognitive aging.

中文翻译：

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秀丽隐杆线虫的热敏神经元反应特性和形态以及热出租车行为的年龄依赖性变化。

年龄相关的认知和行为恶化可能源于神经系统不同组成部分的缺陷，包括神经元，突触，神经胶质细胞或它们的组合。我们发现AFD，秀丽隐杆线虫的主要热感觉神经元，在老年动物中，其特征是感觉末梢完整性的丧失，包括基于肌动蛋白的微绒毛减少和热感觉鸟苷酰环化酶的聚集。在功能水平上，年老动物的AFD神经元对高温过敏，并表现出持续的感觉诱发的钙动力学，从而延长了手术范围。在行为水平上，衰老的动物表现出低温行为，这种行为对急性温度变化仍然具有可塑性。AFD特异性鸟苷酰环化酶GCY-8的过度环化酶活性与AFD感官末端和嗜冷行为的发育缺陷有关。出乎意料的是，GCY-8环化酶结构域的缺失减少了这些年龄相关的形态和行为变化，而gcy-8仍然存在延长的AFD操作范围动物。初级感觉神经元的形态或刺激诱发的反应特性与相关行为之间的年龄相关变化之间缺乏明显的相关性，这凸显了在结构和功能水平上解释与年龄相关的变化时，对衰老特征进行定量分析的重要性。我们的工作确定了AFD接受结局，温度诱发的AFD响应和基于经验的热出租车行为中的衰老标志，它们是进一步阐明认知衰老的神经基础的基础。