Farovik Anja, Dupont Laura M, Arce Miguel, Eichenbaum Howard
Center for Memory and Brain, Boston University, Boston, Massachusetts 02215, USA.
J Neurosci. 2008 Dec 10;28(50):13428-34. doi: 10.1523/JNEUROSCI.3662-08.2008.
There is continuing controversy about the extent to which the rodent medial prefrontal cortical area (mPFC) is functionally homologous to the dorsolateral prefrontal cortex in humans and nonhuman primates. Previous studies have compared the effects of mPFC lesions in rats to those of dorsolateral prefrontal lesions in working memory, strategy switching, and temporal ordering. None, however, has examined the role of the rodent mPFC in recognition memory, wherein, in humans, dorsolateral prefrontal damage results in a deficit in source monitoring resulting in impaired recollection. In the present study, we examined recognition memory in rats with bilateral mPFC lesions (prelimbic/infralimbic regions; ibotenic acid) using a variant of a non-match-to-sample task with manipulations of response bias that allowed for a signal detection analysis that distinguishes recollection and familiarity contributions to recognition memory. Animals with medial prefrontal lesions had a modest overall deficit in recognition with no general change in their tendency to elicit "old" or "new" responses. Signal detection analyses indicated that rats with mPFC damage had a curvilinear and symmetrical receiver operating characteristic (ROC) curve, compared with a curvilinear and asymmetrical ROC curve in control subjects, indicating that mPFC damage severely reduced recollection-based performance, while sparing familiarity. The recollection failure was associated with an impaired ability to reject new items (increased false alarm rate), whereas the identification of old items (hit rate) was normal. This pattern of findings is similar to that observed in humans with dorsolateral prefrontal damage and is complementary to the selective deficit in hit rate observed after hippocampal damage.
啮齿动物的内侧前额叶皮质区域(mPFC)在功能上与人类和非人类灵长类动物的背外侧前额叶皮质的同源程度一直存在争议。先前的研究比较了大鼠mPFC损伤与背外侧前额叶损伤在工作记忆、策略转换和时间排序方面的影响。然而,尚无研究考察啮齿动物mPFC在识别记忆中的作用,而在人类中,背外侧前额叶损伤会导致源监测缺陷,进而损害回忆。在本研究中,我们使用一种非匹配样本任务的变体,对双侧mPFC损伤(边缘前区/边缘下区;鹅膏蕈氨酸)的大鼠进行识别记忆测试,并对反应偏差进行操作,从而进行信号检测分析,以区分回忆和熟悉度对识别记忆的贡献。内侧前额叶损伤的动物在识别方面总体上有适度的缺陷,但其引发“旧”或“新”反应的倾向没有普遍变化。信号检测分析表明,与对照组呈曲线且不对称的接收者操作特征(ROC)曲线相比,mPFC损伤的大鼠具有曲线且对称的ROC曲线,这表明mPFC损伤严重降低了基于回忆的表现,而熟悉度则未受影响。回忆失败与拒绝新项目的能力受损(误报率增加)有关,而识别旧项目(命中率)则正常。这一结果模式与背外侧前额叶损伤的人类中观察到的情况相似,并且与海马损伤后观察到的命中率选择性缺陷互为补充。