Saviane Chiara, Silver R Angus
University College London, London, UK.
Methods Mol Biol. 2007;403:303-17. doi: 10.1007/978-1-59745-529-9_19.
The functional properties of central synapses are difficult to study because they can be modulated either presynaptically or postsynaptically, each connection has multiple contacts and release at each contact is stochastic. Moreover, studying central synapses with electrophysiology is complicated by the fact that synapses are often remote from the recording site and signals are often difficult to resolve above the noise. This together with the fact that central synapses often have few release sites and have nonuniform quantal parameters makes classical quantal analysis methods difficult to apply. Here, we discuss an alternative approach, multiple-probability fluctuation analysis (MPFA), which can be used to estimate nonuniform quantal parameters from fits of the relationship between the variance and mean amplitude of postsynaptic responses, recorded at different release probabilities. We illustrate the experimental protocols and the analysis procedure that should be followed to perform MPFA and interpret the estimated parameters.
中枢突触的功能特性难以研究，因为它们可在突触前或突触后受到调制，每个连接都有多个接触点，且每个接触点的释放是随机的。此外，用电生理学方法研究中枢突触很复杂，原因在于突触通常远离记录位点，信号往往难以在噪声之上分辨出来。再加上中枢突触通常释放位点较少且量子参数不均匀，使得经典的量子分析方法难以应用。在此，我们讨论一种替代方法，即多概率涨落分析（MPFA），它可用于根据在不同释放概率下记录的突触后反应的方差和平均幅度之间关系的拟合来估计不均匀的量子参数。我们阐述了进行MPFA并解释估计参数时应遵循的实验方案和分析程序。
