This project examines the hypothesis that sleep is regulated in part by humoral sleep regulatory substances (SRSs). We focus on interleukin-1 beta (IL1) and related SRSs. Second order hypotheses examined are: a) SRS levels depend on prior neural use and sleep; b) SRSs act locally to affect a sleep regulatory molecular network; c) SRSs act locally in the cerebral cortex as well as within known sleep regulatory circuits to induce sleep; d) changes in SRSs within the cortex activate pathways, such as the corticothalamic and basal forebrain-cortical pathways, known to be involved in sleep regulation. Each of the specific aims targets these hypotheses. In specific aim 1, we determine whether expressions of SRSs are activity-dependent and targeted to the activated areas. Further, we also determine sleep-dependency of SRSs expression. In specific aim 2, we examine the molecular network within which SRSs (IL1 and nerve growth factor [NGF]) act. We will determine their effects on other SRSs, negative feedback molecules (IL4 and IL10) and downstream effector molecules (nuclear factor kappa B and nitric oxide synthase). In specific aim 3, we will determine whether IL1 and NGF can induce localized EEG synchronization within the somatosensory cortex (SSctx), whether sleep deprivation-enhanced EEG delta power can be locally inhibited using IL1 and NGF inhibitors. In specific aim 4, we map some of the neuroanatomical connections of the cortical neurons activated by IL-1beta. An anterograde tracer, biotinylated dextran amine (BDA), or a retrograde tracer, Fluoro-gold (FG), will be iontophoresed into layer V of the SSctx. Co-localization of BDA or FG with Fos-immunoreactivity (IR), or IL-1beta-IR or NGF-IR. will be determined. Successful completion of the aims will: a) help establish whether SRS production is sleep and activity dependent; b) define a sleep molecular network; c) determine whether sleep intensity is a localized property of cortical neuronal groups and d) elucidate some of the pathways by which cortical neuronal groups interact with sleep regulatory circuits. Anticipated results will help establish a unique view of biochemical sleep mechanisms and will thereby significantly impact sleep medicine and sleep research.