Neuropeptides and other mediators in the central nervous system.

Some general principles of peptide and other transmitter actions in the CNS may be applicable to determining how central, autonomic, or blood-borne transmitter signals may regulate the responsiveness of the cells of the immune system. For the resolution of how and where transmitters act in the CNS, research in cellular neurobiology has made substantial recent progress in three specific areas of work: neuronal connectivity, synaptic mechanisms, and neuronal transmitters, Together, the new circuits, new transmitters, and new receptor mechanisms provide a rich repertoire of signaling mechanisms that transcend earlier notions of "classical" excitatory or inhibitory transmission modes and that are pertinent to regulation of immune response mechanisms.