Sacchetti Benedetto, Baldi Elisabetta, Lorenzini Carlo Ambrogi, Bucherelli Corrado
Department of Neuroscience, University of Turin, Corso Raffaello 30, 10125, Turin, Italy.
Exp Brain Res. 2003 Oct;152(3):323-8. doi: 10.1007/s00221-003-1534-1. Epub 2003 Jul 31.
The aim of the present work was to investigate, by means of the reversible inactivation technique, the distinct roles of three neocortical sites, the Prefrontal (PFC), Frontal (FC) and Parietal (PAC) cortices, during memory consolidation of conditioned freezing to a tone, a defined conditioned stimulus (CS), and to the training context. Reversible tetrodotoxin inactivations were performed at increasing post-acquisition delays (0.25, 24 or 96 h). Retention testing was always performed 72 h after the inactivation procedure in order to avoid any possible influence on the retrieval phase. It was found that none of the three sites are involved in context freezing consolidation, but that FC and PAC are differentially involved in the consolidation of memory to the CS. FC inactivation was followed by retention impairment only when performed immediately after acquisition while PAC inactivation was followed by amnesia when performed both immediately after acquisition and 24 h later, but not when performed 96 h later. PFC inactivation was not followed by retention impairment at any of the employed delays. These findings show that some neocortical structures are involved in auditory-cued fear conditioning during the initial phases of the consolidation process.
本研究的目的是通过可逆失活技术，研究前额叶（PFC）、额叶（FC）和顶叶（PAC）皮质这三个新皮质位点在对音调（一种特定的条件刺激，CS）和训练环境的条件性僵立记忆巩固过程中的不同作用。在习得后不同延迟时间（0.25、24或96小时）进行可逆性河豚毒素失活处理。为避免对检索阶段产生任何可能的影响，失活程序后72小时始终进行记忆保持测试。结果发现，这三个位点均不参与环境性僵立巩固，但FC和PAC在对CS的记忆巩固中发挥不同作用。仅在习得后立即进行FC失活会导致记忆保持受损，而PAC失活在习得后立即进行以及24小时后进行均会导致遗忘，但在96小时后进行则不会。在所采用的任何延迟时间进行PFC失活均不会导致记忆保持受损。这些发现表明，在巩固过程的初始阶段，一些新皮质结构参与了听觉线索恐惧条件反射。
