Time course of dorsal and ventral hippocampal involvement in the expression of trace fear conditioning
Time course of dorsal and ventral hippocampal involvement in the expression of trace fear conditioning
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DOI：
10.1016/j.nlm.2013.05.009
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发表时间：
2013-11-01
影响因子：
2.7
通讯作者：
Otto, Tim
中科院分区：
文献类型：
--
作者：
Cox, David;Czerniawski, Jennifer;Otto, Tim
虽然许多早期研究表明，海马体损伤会减弱近期任务的表达，但不会削弱远程训练任务的表达能力，但越来越多的证据表明，海马体损伤或失活往往会损害各种训练测试间隔的记忆能力。总的来说，这些数据表明，海马参与存储或回忆先前获得的记忆的时间过程可能会根据海马分区和所考虑的特定学习任务而有所不同。本研究检查了背侧（DH）和腹侧（VH）海马体对先前获得的微量恐惧条件反射的贡献，这是巴甫洛夫条件反射的一种形式，其中最初中性线索的偏移和厌恶刺激的开始由时间（痕迹）间隔分开。具体而言，在微量恐惧条件反射后 1、7、28 或 42 天进行测试之前，将盐水或 GABA-A 激动剂蝇蕈醇注入 DH 或 VH 中。结果显示出明显的分离：预测试 DH 失活在任何时间点均未损害表现，而预测试 VH 失活则在所有时间点损害表现。重要的是，预测试 VH 失活对先前获得的延迟条件反射的表现没有影响，这表明在微量条件反射中观察到的缺陷不能归因于冻结反应的表现缺陷。总的来说，这些数据表明，VH（而不是 DH）仍然是一个神经解剖学位点，对于长时间内回忆或表达微量恐惧条件反射至关重要。 (C) 2013 年，爱思唯尔公司出版。
While a number of early studies demonstrated that hippocampal damage attenuates the expression of recent, but not remotely trained tasks, an emerging body of evidence has shown that damage to, or inactivation of, the hippocampus often impairs recall across a wide range of training testing intervals. Collectively, these data suggest that the time course of hippocampal involvement in the storage or recall of previously-acquired memories may differ according to hippocampal subregion and the particular learning task under consideration. The present study examined the contributions of dorsal (DH) and ventral (VH) hippocampus to the expression of previously-acquired trace fear conditioning, a form of Pavlovian conditioning in which the offset of an initially neutral cue or cues and the onset of an aversive stimulus is separated by a temporal (trace) interval. Specifically, either saline or the GABA-A agonist muscimol was infused into DH or VH prior to testing either I, 7, 28, or 42 days after trace fear conditioning. The results revealed a marked dissociation: pre-testing inactivation of DH failed to impair performance at any time-point, while pre-testing inactivation of VH impaired performance at all time-points. Importantly, pretesting inactivation of VH had no effect on the performance of previously-acquired delay conditioning, suggesting that the deficits observed in trace conditioning cannot be attributed to a deficit in performance of the freezing response. Collectively, these data suggest that VH, but not DH, remains a neuroanatomical locus critical to the recall or expression of trace fear conditioning over an extended period of time. (C) 2013 Published by Elsevier Inc.