Figure 2
Image analysis for synapsin as protein of interest. (a) Example images of synaptosomes and cultured hippocampal neurons immunostained for synaptophysin, bassoon and synapsin. Scale bar = 10 µm (b) Automatic synapse selection by a custom-written Matlab routine in the areas indicated in the images in a. Synapse detection is based on the signal intensities of the synaptophysin staining (first channel). The selected synapses are numbered so fitted parameters (e.g. intensity) can later be assigned to the respective signals. Scale bar = 5 µm (c) Example of the Gaussian fits for the synapses indicated in panel b. The first image shows the original intensity data (scale in arbitrary units on the far right), the second image shows the model that is fitted to the data, and the third image indicates the residuals, i.e. the deviations of the data from the 2D Gaussian distribution. The R2 values of each fit are indicated on the right. Images are scaled in pixel. Scale bar = 800 nm (5 pixels) (d) Intensity histograms of all fitted synapses for the three channels (prior to final filtering).
