Ambrogi Lorenzini C G, Baldi E, Bucherelli C, Sacchetti B, Tassoni G
Arch Ital Biol. 1998 Nov;136(4):279-96.
By means of permanent lesion techniques it has been possible to ascertain whether a given subcortical neural structure is involved in memory processing. These results, however, are useful only to build a topography of memory, i.e. to provide information only on the "where" such processes take place. Memory being, per se, a temporal process, organized in at least three putative phases (acquisition, consolidation, retrieval) it is of paramount importance to know not only the "where", but also the "when", and, possibly, the "how long" of a given site involvement. The fully reversible inactivation technique has been employed to assess the chronological involvement of subcortical sites. By means of the stereotaxic administration of tetrodotoxin (TTX) it has been possible to inactivate known volumes of nervous tissue for given periods of time. In this way, it has been possible to measure the amnesic effects (disruption of the performance of a passive avoidance response, PAR) after inactivation of discrete neural sites. The data so far obtained by these means are presented and discussed. The comparison of results is justified by the constancy of the experimental subjects (young adult male rats of the same age), the surgical interventions, and the conditioning paradigm (passive avoidance responding in the light-dark box). The parabrachial nuclei, substantia nigra, ventral hippocampus, dorsal hippocampus, nucleus basalis magnocellularis, amygdala, globus pallidus, nucleus caudate-putamen (anterior, median, posterior), medial septal area and nucleus accumbens have been investigated. From these studies, data have been acquired on all three phases of memorization. The most detailed findings concern consolidation. In particular, it was shown that the functional integrity duration necessary to avoid amnesic damages varies greatly from site to site, from at least 15 min to no less than 48 hours. The results confirm and amplify previous experimental work, by defining the chronology of mnemonic involvement of many neural sites. The results are discussed in terms of comparison between sites and connectivity between the investigated sites and other sites or neuronal systems.
通过永久性损伤技术，已能够确定特定的皮层下神经结构是否参与记忆处理。然而，这些结果仅有助于构建记忆的地形图，即仅提供有关这些过程“发生位置”的信息。记忆本身是一个时间过程，至少由三个假定阶段（获取、巩固、检索）组成，因此不仅要知道给定部位参与的“位置”，还要知道“时间”以及可能的“时长”，这至关重要。已采用完全可逆失活技术来评估皮层下部位的时间参与情况。通过立体定向给予河豚毒素（TTX），已能够在给定时间段内使已知体积的神经组织失活。通过这种方式，已能够测量离散神经部位失活后的遗忘效应（被动回避反应，PAR的表现破坏）。展示并讨论了迄今为止通过这些方法获得的数据。结果的比较基于实验对象（相同年龄的年轻成年雄性大鼠）、手术干预和条件范式（明暗箱中的被动回避反应）的一致性。已对臂旁核、黑质、腹侧海马、背侧海马、大细胞基底核、杏仁核、苍白球、尾状核 - 壳核（前、中、后）、内侧隔区和伏隔核进行了研究。从这些研究中，已获取了关于记忆所有三个阶段的数据。最详细的发现涉及巩固。特别是，研究表明避免遗忘损伤所需的功能完整性持续时间因部位而异，从至少15分钟到不少于48小时不等。这些结果通过确定许多神经部位记忆参与的时间顺序，证实并扩展了先前的实验工作。根据各部位之间的比较以及所研究部位与其他部位或神经元系统之间的连接性对结果进行了讨论。
