Frey S, Bergado J A, Frey J U
Leibniz Institute for Neurobiology, Department of Neurophysiology, Brenneckestrasse 6, 39118 Magdeburg, Germany.
Neuroscience. 2003;118(4):1055-62. doi: 10.1016/s0306-4522(03)00029-0.
The prolonged maintenance of hippocampal long-term potentiation (LTP) seems to require heterosynaptic events during its induction. We have previously shown that stimulation of the basolateral nucleus of the amygdala (BLA) within a distinct time window can reinforce a transient early-LTP into a long-lasting late-LTP in the dentate gyrus (DG) in freely moving rats. We have shown that this reinforcement was dependent on beta-adrenergic and/or muscarinergic receptor activation and protein synthesis. However, since the BLA does not directly stimulate the DG the question remained by which inputs such heterosynaptic processes are triggered. We have now directly stimulated the medial septal pathway 15 min after induction of early-LTP in the DG and show that this input is capable of reinforcing early into late-LTP in a frequency-dependent manner. This septal reinforcement of DG LTP was dependent on beta-adrenergic receptor activation and protein synthesis. We suggest that the reinforcing effect of the BLA stimulation can, potentially, be mediated via the septal input to the DG, though it differs in its ability to induce or modulate functional plasticity.
海马体长期增强效应（LTP）的长期维持似乎在其诱导过程中需要异突触事件。我们之前已经表明，在一个特定的时间窗口内刺激杏仁核基底外侧核（BLA），可以将自由活动大鼠齿状回（DG）中的短暂早期LTP增强为持久的晚期LTP。我们已经表明，这种增强依赖于β-肾上腺素能和/或毒蕈碱能受体激活以及蛋白质合成。然而，由于BLA并不直接刺激DG，因此问题依然存在：这种异突触过程是由哪些输入触发的。我们现在在DG中诱导早期LTP 15分钟后直接刺激内侧隔区通路，并表明这种输入能够以频率依赖的方式将早期LTP增强为晚期LTP。DG LTP的这种隔区增强依赖于β-肾上腺素能受体激活和蛋白质合成。我们认为，BLA刺激的增强作用可能通过DG的隔区输入介导，尽管其诱导或调节功能可塑性的能力有所不同。
