Bueno Ana Paula A, de Paiva Joselisa Péres Queiroz, Corrêa Moisés Dos Santos, Tiba Paula Ayako, Fornari Raquel Vecchio
Núcleo de Cognição e Sistemas Complexos, Centro de Matemática, Computação e Cognição, Universidade Federal do ABC, Santo André, SP, Brazil.
Núcleo de Cognição e Sistemas Complexos, Centro de Matemática, Computação e Cognição, Universidade Federal do ABC, Santo André, SP, Brazil.
Physiol Behav. 2017 Mar 15;171:175-180. doi: 10.1016/j.physbeh.2017.01.011. Epub 2017 Jan 9.
It is well established that corticosterone (CORT) enhances memory consolidation of emotionally arousing experiences. Despite emotional memories being usually referred to as well remembered for long periods, there are no studies that have investigated the effects of CORT in modulating the duration and specificity of memory. In the present study, we trained Wistar rats in a single-trial contextual fear conditioning protocol and injected CORT (0.3, 1.0 or 3.0mg/kg), immediately after training, to investigate its effects on memory consolidation. Rats were tested 2 and 29days after the training session or only 29days after training to assess recent or remote memory. Our results show that animals tested for recent memory discriminated the training context from a novel one, while those tested only for remote memory generalized the fear response to both contexts. Animals tested for remote memory after being tested for recent memory were able to discriminate both contexts. These results support the literature regarding memory specificity and duration. However, CORT treatment, even at the dose of 1.0mg/kg that effectively enhanced the plasmatic hormone levels, did not affect the strength or the specificity of memory in either recent or remote memory tests. We hypothesize that the lack of effect of CORT treatment could be due to the low arousing training experience of the single-trial protocol which, despite being sufficient to induce significant recent and remote memory consolidation, may not be sufficient to allow the memory-enhancing effect of CORT.
皮质酮（CORT）能增强对情绪唤起经历的记忆巩固，这一点已得到充分证实。尽管情绪记忆通常被认为能被长期清晰记住，但尚无研究调查CORT在调节记忆持续时间和特异性方面的作用。在本研究中，我们采用单次试验情境恐惧条件反射方案训练Wistar大鼠，并在训练后立即注射CORT（0.3、1.0或3.0mg/kg），以研究其对记忆巩固的影响。在训练 session 后的第2天和第29天或仅在训练后的第29天对大鼠进行测试，以评估近期或远期记忆。我们的结果表明，测试近期记忆的动物能将训练情境与新情境区分开来，而仅测试远期记忆的动物则将恐惧反应泛化到两种情境。在测试近期记忆后再测试远期记忆的动物能够区分两种情境。这些结果支持了关于记忆特异性和持续时间的文献。然而，即使是1.0mg/kg剂量的CORT治疗有效提高了血浆激素水平，在近期或远期记忆测试中也未影响记忆的强度或特异性。我们推测，CORT治疗无效可能是由于单次试验方案的唤醒训练经验较低，尽管这足以诱导显著的近期和远期记忆巩固，但可能不足以产生CORT的记忆增强作用。
