Synaptotagmin 7 (Syt7) is a high-affinity calcium sensor that is implicated in multiple aspects of synaptic transmission. Here, we study the influence of Syt7 on the climbing fiber (CF) to Purkinje cell (PC) synapse. We find that small facilitation and prominent calcium-dependent recovery from depression at this synapse do not rely on Syt7 and that Syt7 is not normally present in CFs. We expressed Syt7 in CFs to assess the consequences of introducing Syt7 to a synapse that normally lacks Syt7. Syt7 expression does not promote asynchronous release or accelerate recovery from depression. Syt7 decreases the excitatory postsynaptic current (EPSC) magnitude, consistent with a decrease in the initial probability of release (P_R). Syt7 also increases synaptic facilitation to such a large extent that it could not arise solely as an indirect consequence of decreased P_R. Thus, the primary consequence of Syt7 expression in CFs, which normally lack Syt7, is to promote synaptic facilitation.

Synaptotagmin 7 (Syt7) 是一种高亲和力钙传感器，与突触传递的多个方面有关。在这里，我们研究了 Syt7 对攀爬纤维 (CF) 到浦肯野细胞 (PC) 突触的影响。我们发现，该突触处的小促进作用和显着的钙依赖性抑郁恢复并不依赖于 Syt7，并且 Syt7 通常不存在于 CF 中。我们在 CF 中表达 Syt7，以评估将 Syt7 引入通常缺乏 Syt7 的突触的后果。 Syt7 表达不会促进异步释放或加速抑郁症的恢复。 Syt7 降低兴奋性突触后电流 (EPSC) 幅度，与初始释放概率 (P _R ) 的降低一致。 Syt7 还在很大程度上增加了突触促进，以至于它不能仅仅作为_PR降低的间接结果而出现。因此，通常缺乏 Syt7 的 CF 中 Syt7 表达的主要结果是促进突触促进。