SLEEP REGULATION - INTERACTIONS AMONG CYTOKINES AND CLASSICAL NEUROTRANSMITTERS

The role of classical neurotransmitters in sleep regulation is amply d ocumented (Hobson and Steriade, 1986). In recent years evidence has be en gathered that immunoactive molecules, infectious agents and their c omponents, or cytokines play some part in sleep regulation (Krueger an d Obal, 1994; Opp et al., 1992; Moldofsky, 1994). Different cytokines possess hypnogenic properties when injected centrally or systemically to different animal species and their role in physiological sleep regu lation is currently under investigation. Little is known of how cytoki nes and classical neurotransmitters interact and of the relevance of t his interaction in sleep induction and maintenance. The present paper (i) reviews data on this topic; (ii) proposes a unitary interpretation whenever possible; and (iii) raises questions that might be addressed by future studies.