Noradrenergic dysfunction accelerates LPS-elicited inflammation-related ascending sequential neurodegeneration and deficits in non-motor/motor functions

Publication date: Available online 24 June 2019Source: Brain, Behavior, and ImmunityAuthor(s): Sheng Song, Qingshan Wang, Lulu Jiang, Esteban Oyarzabal, Natallia V. Riddick, Belinda Wilson, Sheryl S. Moy, Yen-Yu Ian Shih, Jau-Shyong HongAbstractThe loss of central norepinephrine (NE) released by neurons of the locus coeruleus (LC) occurs with aging, and is thought to be an important factor in producing the many of the nonmotor symptoms and exacerbating the degenerative process in animal models of Parkinson’s disease (PD). We hypothesize that selectively depleting noradrenergic LC neurons prior to the induction of chronic neuroinflammation may not only accelerate the rate of progressive neurodegeneration throughout the brain, but may exacerbate nonmotor and motor behavioral phenotypes that recapitulate symptoms of PD. For this reason, we used a “two-hit” mouse model whereby brain NE were initially depleted by DSP-4 one week prior to exposing mice to LPS. We found that pretreatment with DSP-4 potentiated LPS-induced sequential neurodegeneration in SNpc, hippocampus, and motor cortex, but not in VTA and caudate/putamen. Mechanistic study revealed that DSP-4 enhanced LPS-induced microglial activation and subsequently elevated neuronal oxidative stress in affected brain regions in a time-dependent pattern. To further characterize the effects of DSP-4 on non-motor and motor symptoms in the LPS model, physiological and behavioral tests were performed at different time points f...
Source: Brain, Behavior, and Immunity - Category: Neurology Source Type: research