Malin Emily L, Ibrahim Deena Y, Tu Jessica W, McGaugh James L
Center for the Neurobiology of Learning and Memory, Department of Neurobiology and Behavior, University of California, Irvine, CA 92697-3800, USA.
Neurobiol Learn Mem. 2007 Feb;87(2):295-302. doi: 10.1016/j.nlm.2006.09.004. Epub 2006 Oct 31.
Previous findings suggest that the rostral anterior cingulate cortex (rACC) is involved in memory for emotionally arousing training. There is also extensive evidence that the basolateral amygdala (BLA) modulates the consolidation of emotional arousing training experiences via interactions with other brain regions. The present experiments examined the effects of posttraining intra-rACC infusions of the cholinergic agonist oxotremorine (OXO) on inhibitory avoidance (IA) retention and investigated whether the BLA and rACC interact in enabling OXO effects on memory. In the first experiment, male Sprague-Dawley rats were implanted with bilateral cannulae above the rACC and given immediate posttraining OXO infusions. OXO (0.5 or 3 ng) induced significant enhancement of retention performance on a 48-h test. In the second experiment, unilateral posttraining OXO infusions (0.5, 3.0 or 10 ng) enhanced retention when infused into rACC, but not caudal ACC, consistent with previous evidence that ACC is composed of functionally distinct regions. A third experiment investigated the effects of posttraining intra-rACC OXO infusions (0.5 or 10 ng) in rats with bilateral sham or NMDA-induced lesions of the BLA. The BLA lesions did not impair IA retention, but blocked the enhancement induced by posttraining intra-rACC OXO infusions. Lastly, unilateral NMDA lesions of rACC blocked the enhancement of IA retention induced by posttraining ipsilateral OXO infusions into the BLA. These findings support the hypothesis that the rACC is involved in modulating the storage of emotional events and provide additional evidence that the BLA modulates memory consolidation through interactions with efferent brain regions, including the cortex.
先前的研究结果表明，喙前扣带回皮质（rACC）参与了对情绪唤起训练的记忆。也有大量证据表明，基底外侧杏仁核（BLA）通过与其他脑区的相互作用来调节情绪唤起训练经历的巩固。本实验研究了训练后向rACC内注射胆碱能激动剂氧化震颤素（OXO）对抑制性回避（IA）记忆保持的影响，并探讨了BLA和rACC在使OXO对记忆产生作用的过程中是否相互作用。在第一个实验中，雄性Sprague-Dawley大鼠在rACC上方植入双侧套管，并在训练后立即注射OXO。在48小时的测试中，OXO（0.5或3纳克）显著提高了记忆保持表现。在第二个实验中，训练后单侧注射OXO（0.5、3.0或10纳克），注入rACC时能增强记忆保持，但注入尾侧ACC时则不能，这与之前关于ACC由功能不同的区域组成的证据一致。第三个实验研究了在双侧假手术或NMDA诱导的BLA损伤大鼠中，训练后向rACC内注射OXO（0.5或10纳克）的效果。BLA损伤并未损害IA记忆保持，但阻断了训练后向rACC内注射OXO所诱导的增强作用。最后，rACC的单侧NMDA损伤阻断了训练后同侧向BLA注射OXO所诱导的IA记忆保持增强。这些发现支持了rACC参与调节情绪事件存储的假说，并提供了额外的证据，表明BLA通过与包括皮质在内的传出脑区相互作用来调节记忆巩固。
