Dityatev A, Dityateva G, Schachner M
Zentrum für Molekulare Neurobiologie, Universität Hamburg, Germany.
Neuron. 2000 Apr;26(1):207-17. doi: 10.1016/s0896-6273(00)81151-4.
To evaluate the contributions of the pre- versus postsynaptic expression of NCAM in regulation of synaptic efficacy, we cultured dissociated hippocampal cells from NCAM-deficient and wild-type mice in homo- and heterogenotypic combinations. Double recordings from synaptically coupled neurons maintained in heterogenotypic cocultures showed that synaptic strength of excitatory but not inhibitory synapses depended on expression of NCAM post- but not presynaptically. This correlated with higher levels of potentiation and synaptic coverage of NCAM-expressing neurons compared to NCAM-deficient neurons in heterogenotypic cocultures. Synaptic density was the same in homogenotypic cultures of NCAM-deficient and wild-type neurons as well as in heterogenotypic cocultures in which glutamate receptors were blocked. These observations indicate that the relative levels of postsynaptic NCAM expression control synaptic strength in an activity-dependent manner by regulating the number of synapses.
为了评估神经细胞黏附分子（NCAM）在突触前和突触后表达对突触效能调节的贡献，我们将来自NCAM缺陷型和野生型小鼠的海马解离细胞进行同型和异型组合培养。在异型共培养中对突触耦合神经元进行的双记录显示，兴奋性突触而非抑制性突触的突触强度取决于突触后而非突触前的NCAM表达。这与异型共培养中表达NCAM的神经元相比NCAM缺陷型神经元具有更高的增强水平和突触覆盖率相关。在NCAM缺陷型和野生型神经元的同型培养物中以及在谷氨酸受体被阻断的异型共培养物中，突触密度相同。这些观察结果表明，突触后NCAM表达的相对水平通过调节突触数量以活动依赖的方式控制突触强度。
