División de Neurociencias. Instituto de Fisiología Celular. Universidad Nacional Autónoma de México. Circuito Exterior, Ciudad Universitaria, 04510 Mexico City, Mexico.
Learn Mem. 2021 Aug 16;28(9):270-276. doi: 10.1101/lm.052720.120. Print 2021 Sep.
It has been reported that during chemotherapy treatment, some patients can experience nausea before pharmacological administration, suggesting that contextual stimuli are associated with the nauseating effects. There are attempts to reproduce with animal models the conditions under which this phenomenon is observed to provide a useful paradigm for studying contextual aversion learning and the brain structures involved. This manuscript assessed the hippocampus involvement in acquiring and maintaining long-term conditioned place avoidance (CPA) induced by a gastric malaise-inducing agent, LiCl. Our results demonstrate that a reliable induction of CPA is possible after one acquisition trial. However, CPA establishment requires a 20-min confinement in the compartment associated with LiCl administration. Interestingly, both hippocampal regions seem to be necessary for CPA establishment; nonetheless, inactivation of the ventral hippocampus results in a reversion of avoidance and turns it into preference. Moreover, we demonstrate that activation of dorsal/ventral hippocampal NMDA receptors after CS-US association is required for long-term CPA memory maintenance.
据报道，在化疗治疗期间，一些患者在药物治疗前会出现恶心，这表明环境刺激与恶心效应有关。人们试图在动物模型中重现这种现象出现的条件，为研究情境性厌恶学习和涉及的大脑结构提供一个有用的范例。本文评估了海马体在习得和维持由胃部不适诱导剂 LiCl 引起的长期条件性位置回避（CPA）中的作用。我们的结果表明，在一次获得试验后，可靠地诱导 CPA 是可能的。然而，CPA 的建立需要在与 LiCl 给药相关的隔室中禁闭 20 分钟。有趣的是，似乎两个海马区域对于 CPA 的建立都是必需的；然而，腹侧海马体的失活会导致回避反应的逆转，并使其转变为偏好。此外，我们证明，在 CS-US 关联后，背侧/腹侧海马 NMDA 受体的激活对于长期的 CPA 记忆维持是必需的。
