人们普遍认为,某些类型的学习涉及海马突触的结构和功能变化。细胞粘附分子神经细胞粘附分子(NCAM),其聚唾液酸形成聚唾液酸为NCAM(PSA-NCAM),和L1是这些变化的主要调节因素。另一方面,追踪眨眼调理,联想运动学习任务,需要海马回路的积极参与。然而,NCAM的参与,PSA-NCAM,和L1在这种类型的学习是不完全已知的。这里,我们的目的是研究在获得痕量眨眼调节过程中海马中这种神经细胞粘附分子可能的时间序列修饰。要做到这一点,NCAM的海马表达,PSA-NCAM,在调节过程中,在三个不同的时间点评估L1:在一个(初始采集)之后,三(部分采集),和六个(完整的习得)条件化范式。条件刺激(CS)是一个弱电脉冲,与非条件刺激隔开250毫秒的时间间隔(US,强电脉冲)。在海马中发现了这些粘附分子的采集依赖性调节。在最初获得条件眨眼范例期间(训练1天和3天后12小时),L1和PSA-NCAM的突触表达在配对的CS-US表现的对侧海马中短暂增加,然而,当联想学习完成时,这种增加消失了,但是发现了明显的和双侧的NCAM上调。总之,我们的发现显示了在采集过程中海马CAM表达的特定时间模式,强调NCAM的相关性,PSA-NCAM,和L1作为学习调节分子,关键地参与了关联运动记忆形成的重塑过程。
It is widely accepted that some types of learning involve structural and functional changes of hippocampal synapses. Cell adhesion molecules neural cell adhesion molecule (NCAM), its polysialylated form polysialic acid to NCAM (PSA-NCAM), and L1 are prominent modulators of those changes. On the other hand, trace eyeblink conditioning, an associative motor learning task, requires the active participation of hippocampal circuits. However, the involvement of NCAM, PSA-NCAM, and L1 in this type of learning is not fully known. Here, we aimed to investigate the possible time sequence modifications of such neural cell adhesion molecules in the hippocampus during the acquisition of a trace eyeblink conditioning. To do so, the hippocampal expression of NCAM, PSA-NCAM, and L1 was assessed at three different time points during conditioning: after one (initial acquisition), three (partial acquisition), and six (complete acquisition) sessions of the conditioning paradigm. The conditioned stimulus (CS) was a weak electrical pulse separated by a 250-ms time interval from the unconditioned stimuli (US, a strong electrical pulse). An acquisition-dependent regulation of these adhesion molecules was found in the hippocampus. During the initial acquisition of the conditioning eyeblink paradigm (12 h after 1 and 3 days of training), synaptic expression of L1 and PSA-NCAM was transiently increased in the contralateral hippocampus to the paired CS-US presentations, whereas, when the associative learning was completed, such increase disappeared, but a marked and bilateral upregulation of NCAM was found. In conclusion, our findings show a specific temporal pattern of hippocampal CAMs expression during the acquisition process, highlighting the relevance of NCAM, PSA-NCAM, and L1 as learning-modulated molecules critically involved in remodeling processes underlying associative motor-memories formation.