Use of superfused synaptosomes to understand the role of receptor–receptor interactions as integrative mechanisms in nerve terminals from selected brain region

Synaptosomes are sealed presynaptic nerve terminals obtained by homogenizing selected brain regions under iso-osmotic conditions. This preparation has been extensively used to study the mechanism of neurotransmitter release in vitro because they preserve the biochemical, morphological, and electrophysiological properties of the synapse. This allows an unequivocal interpretation of results obtained under accurately specified experimental conditions. By using superfused synaptosome technique, it is possible to individuate the co-localization of different receptors on the same nerve endings and the presence of synergistic/antagonistic interactions between them. The latter opportunity renders superfused synaptosome technique particularly suitable to understand the functional role of receptor–receptor interactions at the presynaptic level. This chapter is mainly focused on a general description of the technique and on its application to investigate the functional relevance of receptor–receptor interactions in regulating neurotransmitter release from selected brain region nerve terminals.