Engram activation reinstates the susceptibility of consolidated memory traces to retrograde amnesia by functional blockade of parabrachial nuclei
Engram activation reinstates the susceptibility of consolidated memory traces to retrograde amnesia by functional blockade of parabrachial nuclei
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DOI：
10.1016/s0166-4328(05)80312-2
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发表时间：
1992-10
影响因子：
2.7
通讯作者：
C. Bucherelli;G. Tassoni
中科院分区：
文献类型：
--
作者：
C. Bucherelli;G. Tassoni
先前的研究表明，大鼠在明暗箱装置中获得的避暗被动回避反应（PAR）被臂旁核（PBN）的河豚毒素（TTX）灭活破坏24，但在获得试验后48小时未被破坏6，24。本实验表明，TTX诱导逆行性遗忘症，即使当应用于PBN 48小时后，PAR收购，只有当它是由一个30分钟的限制（灭绝）或在黑暗的隔间脚电击（再培训）之前。这些刺激，独立于他们的符号，诱导定量可比TTX干扰效果。尽管这些刺激太弱，无法在控制条件下修改PAR，但仍会发生这种情况。这个矛盾的发现表明，记忆痕迹的脆弱性可能不是一个简单的反函数，其近因，但它可能反映了参与记忆痕迹形成的神经回路的重新激活。只有当在应用破坏程序之前不久出现脑内线索刺激时，巩固的记忆痕迹才再次变得脆弱。
Previous studies have shown that in rats the acquisition of a step-through passive avoidance reaction (PAR) in the light-dark box apparatus is disrupted by tetrodotoxin (TTX) inactivation of the parabrachial nuclei (PBN) 24 but not 48 h after the acquisition trial6,24. The present experiment shows that TTX induces retrograde amnesia even when applied to the PBN 48 h after PAR acquisition only if it is preceded by a 30-min confinement (extinction) or by a footshock (retraining) in the dark compartment. These stimuli, independently of their sign, induce quantitatively comparable TTX disrupting effects. This happens notwithstanding the fact that these stimuli are too weak to modify PAR under control conditions. This paradoxical finding suggests that engram vulnerability may not be a simple inverse function of its recency but that it may reflect a reactivation of the neural circuits involved in memory trace formation. Consolidated engrams become again vulnerable only when contestual cue stimuli are presented shortly before the application of the disrupting procedure.