Beta-adrenergic receptor activation primes microglia cytokine production

Exaggerated pro-inflammatory cytokine production by primed microglia is thought to mediate pathology during stress, aging, and neurodegeneration. Recently, it was demonstrated that beta-adrenergic receptor (beta-AR) antagonism prevents priming of microglia in mice exposed to chronic stress. To determine if beta-AR stimulation is sufficient to prime microglia, rats were intra-cerebroventricularly administered isoproterenol (beta-AR agonist) or vehicle and 24 h later hippocampal microglia were placed in culture with media or LPS. Prior isoproterenol treatment significantly enhanced IL-1 beta and IL-6, but not TNF-alpha production following LPS stimulation. These data suggest that central beta-AR stimulation is sufficient to prime microglia cytokine responses. (C) 2012 Elsevier B.V. All rights reserved.