Long description

This is an image taken through an electron microscope showing the internal features in the region of a synapse. The image is highly magnified and contains a number of bubble-like structures of different sizes. One bubble to the lower left is the axon terminal of the presynaptic neuron. The scale indicates that it has a diameter of about half a micrometre. It is filled with numerous small round structures which are the synaptic vesicles containing neurotransmitters. Above and in close contact with this is part of a dendrite of postsynaptic neuron. It is filled with some darker blobs of varying sizes which are not labelled. Separating the pre- and postsynaptic neurons is a gap called the synaptic cleft. There are some other similar structures in the image which aren’t identified.