Long-term potentiation (LTP) in the hippocampus is the most studied form of synaptic plasticity. Temporal integration of synaptic inputs is essential in synaptic plasticity and is assumed to be achieved through Ca²⁺ signaling in neurons and astroglia. However, whether these two cell types play different roles in LTP remain unknown. Here, we found that through the integration of synaptic inputs, astrocyte inositol triphosphate (IP₃) receptor type 2 (IP₃R2)-dependent Ca²⁺ signaling was critical for late-phase LTP (L-LTP) but not early-phase LTP (E-LTP). Moreover, this process was mediated by astrocyte-derived brain-derived neurotrophic factor (BDNF). In contrast, neuron-derived BDNF was critical for both E-LTP and L-LTP. Importantly, the dynamic differences in BDNF secretion play a role in modulating distinct forms of LTP. Moreover, astrocyte- and neuron-derived BDNF exhibited different roles in memory. These observations enriched our knowledge of LTP and memory at the cellular level and implied distinct roles of astrocytes and neurons in information integration.

海马体中的长时程增强 (LTP) 是研究最多的突触可塑性形式。突触输入的时间整合在突触可塑性中是必不可少的，并且被认为是通过神经元和星形胶质细胞中的Ca ^{2+信号传导来实现的。}然而，这两种细胞类型是否在 LTP 中发挥不同的作用仍然未知。在这里，我们发现通过整合突触输入，星形胶质细胞肌醇三磷酸 (IP ₃ ) 受体 2 型 (IP ₃ R2) 依赖性 Ca ²⁺信号传导对晚期 LTP (L-LTP) 至关重要，但对早期 LTP (E-LTP) 则不然。此外，这一过程是由星形胶质细胞衍生的脑源性神经营养因子 (BDNF) 介导的。相反，神经元衍生的 BDNF 对 E-LTP 和 L-LTP 都至关重要。重要的是，BDNF 分泌的动态差异在调节不同形式的 LTP 中发挥作用。此外，星形胶质细胞和神经元衍生的 BDNF 在记忆中表现出不同的作用。这些观察丰富了我们在细胞水平上对 LTP 和记忆的了解，并暗示了星形胶质细胞和神经元在信息整合中的不同作用。