PDF(Pubmed)
Abstract：
Hippocampal networks required for associative memory formation are involved in cue- and context-dependent threat conditioning. The hippocampus is functionally heterogeneous at its dorsal and ventral poles, and recent investigations have focused on the specific roles required from each sub-region for associative conditioning. Cumulative evidence suggests that contextual and emotional information is processed by the dorsal and ventral hippocampus, respectively. However, it is not well understood how these two divisions engage in threat conditioning with cues of different sensory modalities. Here, we compare the involvement of the dorsal and ventral hippocampus in two types of threat conditioning: olfactory and auditory. Our results suggest that the dorsal hippocampus encodes contextual information and is activated upon recall of an olfactory threat memory only if contextual cues are relevant to the threat. Overnight habituation to the context eliminates dorsal hippocampal activation, implying that this area does not directly support cue-dependent threat conditioning. The ventral hippocampus is activated upon recall of olfactory, but not auditory, threat memory regardless of habituation duration. Concurrent activation of the piriform cortex is consistent with its direct connection with the ventral hippocampus. Together, our study suggests a unique role of the ventral hippocampus in olfactory threat conditioning.
摘要：
联想记忆形成所需的海马网络涉及线索和上下文相关的威胁条件。海马在背侧和腹侧两极的功能上是异质的，最近的调查集中在每个子区域所需的关联条件的具体作用。累积证据表明，上下文和情绪信息是由背侧和腹侧海马处理的，分别。然而,目前还不清楚这两个部门是如何利用不同感官模式的线索进行威胁调节的。这里,我们比较了背侧和腹侧海马受累于两种类型的威胁条件：嗅觉和听觉。我们的结果表明，背侧海马会编码上下文信息，并且只有在上下文提示与威胁相关的情况下，才会在回忆嗅觉威胁记忆时被激活。对环境的过夜习惯消除了背侧海马的激活，这意味着该区域不直接支持依赖线索的威胁条件。回忆起嗅觉后，腹侧海马被激活，但不是听觉，威胁记忆，无论习惯持续时间如何。梨状皮层的同时激活与其与腹侧海马体的直接连接是一致的。一起,我们的研究提示腹侧海马体在嗅觉威胁调节中的独特作用.
