Input-timing-dependent plasticity (ITDP) is a circuit-based synaptic learning rule by which paired activation of entorhinal cortical (EC) and Schaffer collateral (SC) inputs to hippocampal CA1 pyramidal neurons (PNs) produces a long-term enhancement of SC excitation. We now find that paired stimulation of EC and SC inputs also induces ITDP of SC excitation of CA2 PNs. However, whereas CA1 ITDP results from long-term depression of feedforward inhibition (iLTD) as a result of activation of CB1 endocannabinoid receptors on cholecystokinin-expressing interneurons, CA2 ITDP results from iLTD through activation of δ-opioid receptors on parvalbumin-expressing interneurons. Furthermore, whereas CA1 ITDP has been previously linked to enhanced specificity of contextual memory, we find that CA2 ITDP is associated with enhanced social memory. Thus, ITDP may provide a general synaptic learning rule for distinct forms of hippocampal-dependent memory mediated by distinct hippocampal regions.

中文翻译：

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海马CA2区输入-时间依赖性可塑性及其在社会记忆中的潜在作用。

输入时序依赖可塑性（ITDP）是基于电路的突触学习规则，通过该规则，对海马CA1锥体神经元（PNs）的内嗅皮层（EC）和Schaffer侧支（SC）输入的配对激活会产生SC的长期增强励磁。现在我们发现，成对的EC和SC输入的刺激还可以诱导CA2 PNs的SC激发的ITDP。然而，CA1 ITDP是由于表达胆囊收缩素的中间神经元上的CB1内源性大麻素受体活化而长期抑制前馈抑制（iLTD）产生的，而CA2 ITDP是iLTD是通过激活表达白蛋白的中间神经元上的δ阿片受体而产生的。此外，尽管CA1 ITDP先前已与上下文记忆的增强的特异性相关联，但我们发现CA2 ITDP与增强的社交记忆相关。因此，