(#99126. The fibers in this montage (green, labeled with a tracer) show swellings very close to spines on a dendrite filled with a dye called Neurobiotin (red). The left upper picture is a so-called extended focus image: all 60 frames of the Z-series are compressed into one flat image. The right upper picture you will see animated every second image of the Z-series once you place the mouse cursor over the image. The picture left is a 3D reconstruction of the circled area, showing the contact in detail.
On the left is a movie that you can play. Its size is 5.5 megabytes. It shows a rotation and further zooms in on the structures displayed above
The (red) terminal on the left is very close to the green dendrite. On this movie the assembly is rotated to give you a better view (2.7 megabytes)
 
Making use of all three channels of the confocal microscope, one can study colocalization of three markers. This rotation shows how these three markers are interrelated: red (synaptophysin) inside the blue axon terminals, green (postsynaptic density protein) outside or on the edges (7.7 Mb)
Last but not least: 3D reconstruction of a fiber (red) with three swellings on its path. The left swelling contains the second marker (green) indicating the presence of synaptophysin, a protein associated with synaptic vesicles. You are looking here at an axon terminal!