Behavioral and cellular dopamine D and D receptor-mediated synergy: Implications for L-DOPA-induced dyskinesia.

Individually, D1 and D3 dopamine receptors (DR and DR, respectively) have been implicated in L-DOPA-induced dyskinesia (LID). Of late, direct DR-DR interactions have been linked to LID yet remain enigmatic. Therefore, the current research sought to characterize consequences of putative DR-DR interactions in dyskinesia expression and in LID-associated downstream cellular signaling.

The impact of the P2X7 receptor antagonist A-804598 on neuroimmune and behavioral consequences of stress.

Stress leads to neuroinflammatory and behavioral consequences through upregulation of inflammatory-related cytokines within the central nervous system such as interleukin-1β (IL-1β), which may be indicative of microglial priming/activation. Evidence suggests that the P2X7 receptor (P2X7R) may play an important role in the synthesis and conversion of IL-1β. In a series of six experiments, adult male rats were intubated with a highly selective P2X7R antagonist (A-804598) before footshock exposure.

Stress-induced increases in hypothalamic IL-1: a systematic analysis of multiple stressor paradigms.

Exposure to stressors such as footshock, tailshock, and immobilization have been shown to induce hypothalamic IL-1 production, while other stressors such as restraint, maternal separation, social isolation, and predator exposure have no effect on hypothalamic IL-1 levels. This disparity of findings has led to considerable controversy regarding the ability of stressors to induce hypothalamic IL-1 expression. Thus, the goal of the following experiments was to examine hypothalamic IL-1 responses in adult male Sprague-Dawley rats following exposure to a diverse set of stressors.

Insulin-like growth factor-I diminishes the activation status and expression of the small GTPase Cdc42 in articular chondrocytes.

Insulin-like growth factor-I (IGF-I) is an important anabolic growth factor in the maintenance of articular cartilage phenotypic expression. Chondrocyte morphology is also tightly linked to phenotype. The small G-protein Cdc42 plays a key role in regulation of cell morphology and phenotypic expression in several cell types and, we show here, in articular chondrocytes.

Further characterization of high mobility group box 1 (HMGB1) as a proinflammatory cytokine: central nervous system effects.

High mobility group box 1 (HMGB1), an abundant, highly conserved cellular protein, is widely known as a nuclear DNA-binding protein. HMGB1 has been recently implicated as a proinflammatory cytokine because of its role as a late mediator of endotoxin lethality and ability to stimulate release of proinflammatory cytokines from monocytes. Production of central cytokines is a critical step in the pathway by which endotoxin and peripheral proinflammatory cytokines, including interleukin-1beta (IL-1) and tumor necrosis factor-alpha (TNF), produce sickness behaviors and fever.