Dorsal hippocampal contributions to unimodal contextual conditioning
Dorsal hippocampal contributions to unimodal contextual conditioning
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DOI：
10.1523/jneurosci.1056-06.2006
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发表时间：
2006-06-14
影响因子：
5.3
通讯作者：
Poon, Patrick
中科院分区：
文献类型：
--
作者：
Otto, Tim;Poon, Patrick
尽管人们普遍认为海马体并不直接参与外显条件刺激（CS）的恐惧习得，但海马体参与情境恐惧条件反射的程度仍不清楚。为了进一步表征海马体在情境恐惧条件反射中的潜在作用，本实验研究了海马体背侧兴奋毒性损伤对一种新的情境恐惧条件反射范式习得的影响，在这种范式中，单峰（嗅觉）线索用于消除单一行为训练室中离散“情境”的歧异。海马背侧选择性病变严重削弱嗅觉情境条件反射，但不影响对显性听觉或嗅觉CS的条件反射。其他实验表明，这些情境条件反射缺陷不能归因于病变引起的嗅觉知觉下降、“弱”条件反射形式的优先损害或过度活跃。因此，海马体似乎对明确非空间、单峰、时间和空间扩散的情境刺激的恐惧习得起重要作用。
Although there is general consensus that the hippocampus is not critically involved in the acquisition of fear conditioned to an explicit conditioned stimulus (CS), the extent to which the hippocampus participates in contextual fear conditioning remains unclear. To further characterize the potential role of the hippocampus in contextual fear conditioning, the present experiments examined the effect of excitotoxic lesions of dorsal hippocampus on the acquisition of a novel contextual fear conditioning paradigm in which a unimodal (olfactory) cue served to disambiguate discrete "contexts" within a single behavioral training chamber. Selective lesions of dorsal hippocampus severely attenuated olfactory contextual conditioning without affecting conditioning to an explicit auditory or olfactory CS. Additional experiments indicate that these contextual conditioning deficits cannot be attributed to a lesion-induced decrement in olfactory perception, a preferential impairment of "weak" forms of conditioning, or hyperactivity. Thus, the hippocampus appears to contribute importantly to the acquisition of fear conditioned to explicitly nonspatial, unimodal, temporally, and spatially diffuse contextual stimuli.