Urocanic acid (UCA) is an endogenous small molecule that is elevated in skin, blood and brain after sunlight exposure, mainly playing roles in the periphery systems. Few studies have investigated the role of UCA in the central nervous system. In particular, its role in memory consolidation and reconsolidation is still unclear. In the present study, we investigated the effect of intraperitoneal injection of UCA on memory consolidation and reconsolidation in a novel object recognition memory (ORM) task. In the consolidation version of the ORM task, the protocol involved three phases: habituation, sampling and test. UCA injection immediately after the sampling period enhanced ORM memory performance; UCA injection 6 h after sampling did not affect ORM memory performance. In the reconsolidation version of the ORM task, the protocol involved three phases: sampling, reactivation and test. UCA injection immediately after reactivation enhanced ORM memory performance; UCA injection 6 h after reactivation did not affect ORM memory performance; UCA injection 24 h after sampling without reactivation did not affect ORM memory performance. This UCA-enhanced memory performance was not due to its effects on nonspecific responses such as locomotor activity and exploratory behavior. The results suggest that UCA injection enhances consolidation and reconsolidation of an ORM task, which further extends previous research on UCA effects on learning and memory.

尿烷酸 (UCA) 是一种内源性小分子，在阳光照射后会在皮肤、血液和大脑中升高，主要在外周系统中起作用。很少有研究调查 UCA 在中枢神经系统中的作用。尤其是其在记忆巩固和再巩固中的作用尚不清楚。在本研究中，我们研究了腹腔注射 UCA 对新物体识别记忆 (ORM) 任务中记忆巩固和再巩固的影响。在 ORM 任务的整合版本中，协议涉及三个阶段：习惯化、采样和测试。采样周期后立即注入 UCA 增强了 ORM 内存性能；采样后 6 小时注入 UCA 不会影响 ORM 内存性能。在ORM任务的再整合版本中，该协议涉及三个阶段：采样、重新激活和测试。重新激活后立即注入 UCA 增强了 ORM 内存性能；重新激活后 6 h 注入 UCA 不影响 ORM 内存性能；在没有重新激活的情况下采样后 24 小时注射 UCA 不会影响 ORM 内存性能。这种 UCA 增强的记忆性能不是由于其对非特异性反应（如运动活动和探索行为）的影响。结果表明，UCA 注射增强了 ORM 任务的巩固和再巩固，这进一步扩展了先前关于 UCA 对学习和记忆影响的研究。在没有重新激活的情况下采样后 24 小时注射 UCA 不会影响 ORM 内存性能。这种 UCA 增强的记忆性能不是由于其对非特异性反应（如运动活动和探索行为）的影响。结果表明，UCA 注射增强了 ORM 任务的巩固和再巩固，这进一步扩展了先前关于 UCA 对学习和记忆影响的研究。在没有重新激活的情况下采样后 24 小时注射 UCA 不会影响 ORM 内存性能。这种 UCA 增强的记忆性能不是由于其对非特异性反应（如运动活动和探索行为）的影响。结果表明，UCA 注射增强了 ORM 任务的巩固和再巩固，这进一步扩展了先前关于 UCA 对学习和记忆影响的研究。