Fine-tuning neuromodulation by adenosine

In addition to its direct pre- and postsynaptic actions on neurones, adenos ine is rich in nuances of priming, triggering and inhibiting the action of several neurotransmitters and neuromodulators. These actions are mediated b y membrane adenosine receptors (A(1), A(2) and A(3)) and involve receptor-r eceptor interactions, which require, in most cases, the formation of an int ermediate second messenger. The harmonic way adenosine builds its influence at synapses to control neuronal communication is operated through fine-tun ing, 'synchronizing' or 'desynchronizing' receptor activation for neuropept ides such as calcitonin gene-related peptide and vasoactive intestinal pept ide, nicotinic acetylcholine autofacilitatory receptors, NMDA receptors, me tabotropic glutamate receptors, as well as its own adenosine receptors.