Martin K C, Casadio A, Zhu H, Yaping E, Rose J C, Chen M, Bailey C H, Kandel E R
Center for Neurobiology and Behavior, College of Physicians and Surgeons of Columbia University, New York, New York 10032, USA.
Cell. 1997 Dec 26;91(7):927-38. doi: 10.1016/s0092-8674(00)80484-5.
The requirement for transcription during long-lasting synaptic plasticity has raised the question of whether the cellular unit of synaptic plasticity is the soma and its nucleus or the synapse. To address this question, we cultured a single bifurcated Aplysia sensory neuron making synapses with two spatially separated motor neurons. By perfusing serotonin onto the synapses made onto one motor neuron, we found that a single axonal branch can undergo long-term branch-specific facilitation. This branch-specific facilitation depends on CREB-mediated transcription and involves the growth of new synaptic connections exclusively at the treated branch. Branch-specific long-term facilitation requires local protein synthesis in the presynaptic but not the postsynaptic cell. In fact, presynaptic sensory neuron axons deprived of their cell bodies are capable of protein synthesis, and this protein synthesis is stimulated 3-fold by exposure to serotonin.
在持久的突触可塑性过程中对转录的需求引发了一个问题，即突触可塑性的细胞单位是胞体及其细胞核还是突触。为了解决这个问题，我们培养了一个单一的、分叉的海兔感觉神经元，它与两个空间上分离的运动神经元形成突触。通过将5-羟色胺灌注到与一个运动神经元形成的突触上，我们发现单个轴突分支可以经历长期的分支特异性易化。这种分支特异性易化依赖于CREB介导的转录，并且仅在被处理的分支处涉及新突触连接的生长。分支特异性长期易化需要突触前而非突触后细胞中的局部蛋白质合成。事实上，剥夺了细胞体的突触前感觉神经元轴突能够进行蛋白质合成，并且这种蛋白质合成在暴露于5-羟色胺时会被刺激3倍。
