Enhancement of extinction memory consolidation: The role of the noradrenergic and GABAergic systems within the basolateral amygdala
Enhancement of extinction memory consolidation: The role of the noradrenergic and GABAergic systems within the basolateral amygdala
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DOI：
10.1016/j.nlm.2005.12.008
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发表时间：
2006-09-01
影响因子：
2.7
通讯作者：
McGaugh, James L.
中科院分区：
文献类型：
--
作者：
Berlau, Daniel J.;McGaugh, James L.
以往的研究表明，基底外侧杏仁核（BLA）内的去甲肾上腺素能和GABA能影响调节恐惧条件反射记忆的巩固。本实验研究是否同样的调制影响参与调节的消退恐惧为基础的学习。为了研究这个问题，雄性Sprague道利大鼠植入单侧或双侧carmula针对BLA进行训练的上下文恐惧条件反射（CFC）的任务，24和48小时后给予灭绝训练。在每次消退后，他们立即接受GABA能拮抗剂荷包牡丹碱（50 ng）、β-肾上腺素受体拮抗剂普萘洛尔（500 ng）、荷包牡丹碱与普萘洛尔、去甲肾上腺素（NE）（0.3、1.0和3.0 μ g）、GABA能激动剂蝇蕈醇（125 ng）、NE与蝇蕈醇或对照溶液的BLA内输注。为了研究背侧海马（DH）的参与作为灭绝过程中BLA激活的可能靶点，通过植入DH的同侧carmula向其他动物输注蝇蕈醇（500 ng）。双侧BLA输注荷包牡丹碱显著增强了消退，输注到右侧BLA也是如此，但左侧BLA没有。右侧BLA注入心得安和荷包牡丹碱可阻断荷包牡丹碱引起的记忆增强作用。去甲肾上腺素输注到右BLA也增强了消光，这种作用并没有被蝇蕈醇的共同输注阻断。此外，向DH中注入蝇蕈醇不会减弱向BLA中注入去甲肾上腺素的记忆增强作用。这些研究结果提供的证据表明，与原始CFC学习，BLA内的去甲肾上腺素能激活调制CFC灭绝的巩固。研究结果还表明，BLA对灭绝的影响不是通过与背侧海马体的相互作用介导的，（c）2005 Elsevier Inc. All rights reserved.
Evidence from previous studies indicates that the noradrenergic and GABAergic influences within the basolateral amygdala (BLA) modulate the consolidation of memory for fear conditioning. The present experiments investigated whether the same modulatory influences are involved in regulating the extinction of fear-based learning. To investigate this issue, male Sprague Dawley rats implanted with unilateral or bilateral carmula aimed at the BLA were trained on a contextual fear conditioning (CFC) task and 24 and 48 h later were given extinction training. Immediately following each extinction session they received intra-BLA infusions of the GABAergic antagonist bicuculline (50 ng), the beta-adrenocepter antagonist propranolol (500 ng), bicuculline with propranolol, norepinephrine (NE) (0.3, 1.0, and 3.0 mu g), the GABAergic agonist muscimol (125 ng), NE with muscimol or a control solution. To investigate the involvement of the dorsal hippocampus (DH) as a possible target of BLA activation during extinction, other animals were given infusions of muscimol (500 ng) via an ipsilateral carmula implanted in the DH. Bilateral BLA infusions of bicuculline significantly enhanced extinction, as did infusions into the right, but not left BLA. Propranolol infused into the right BLA together with bicuculline blocked the bicuculline-induced memory enhancement. Norepinephrine infused into the right BLA also enhanced extinction, and this effect was not blocked by co-infusions of muscimol. Additionally, muscimol infused into the DH did not attenuate the memory enhancing effects of norepinephrine infused into the BLA. These findings provide evidence that, as with original CFC learning, noradrenergic activation within the BLA modulates the consolidation of CFC extinction. The findings also suggest that the BLA influence on extinction is not mediated by an interaction with the dorsal hippocampus, (c) 2005 Elsevier Inc. All rights reserved.