Gottmann Kurt
Institut für Neuro- und Sinnesphysiologie, Heinrich-Heine Universität, Düsseldorf, Germany.
J Neurosci Res. 2008 Feb 1;86(2):223-32. doi: 10.1002/jnr.21484.
Delicate control of the synaptic vesicle cycle is required to meet the demands imposed on synaptic transmission by the brain's complex information processing. In addition to intensively analyzed intrinsic regulation, extrinsic modulation of the vesicle cycle by the postsynaptic target neuron has become evident. Recent studies have demonstrated that several families of synaptic cell-adhesion molecules play a significant role in transsynaptic retrograde signaling. Different adhesion systems appear to specifically target distinct steps of the synaptic vesicle cycle. Signaling via classical cadherins regulates the recruitment of synaptic vesicles to the active zone. The neurexin/neuroligin system has been shown to modulate presynaptic release probability. In addition, reverse signaling via the EphB/ephrinB system plays an important role in the activity-dependent induction of long-term potentiation of presynaptic transmitter release. Moreover, the first hints of involvement of cell-adhesion molecules in vesicle endocytosis have been published. A general hypothesis is that specific adhesion systems might use different but parallel transsynaptic signaling pathways able to selectively modulate each step of the synaptic vesicle cycle in a tightly coordinated manner.
为满足大脑复杂信息处理对突触传递提出的要求，需要对突触小泡循环进行精细控制。除了对内在调节进行深入分析外，突触后靶神经元对小泡循环的外在调节也已变得明显。最近的研究表明，几个突触细胞粘附分子家族在跨突触逆行信号传导中发挥着重要作用。不同的粘附系统似乎专门针对突触小泡循环的不同步骤。通过经典钙粘蛋白的信号传导调节突触小泡向活性区的募集。纽蛋白/神经连接蛋白系统已被证明可调节突触前释放概率。此外，通过EphB/ephrinB系统的逆向信号传导在突触前递质释放的活动依赖性长时程增强诱导中起重要作用。此外，已经发表了关于细胞粘附分子参与小泡内吞作用的初步线索。一个普遍的假设是，特定的粘附系统可能使用不同但平行的跨突触信号通路，能够以紧密协调的方式选择性地调节突触小泡循环的每个步骤。
