Microglial cells have emerged as crucial players in synaptic plasticity during development and adulthood, and also in neurodegenerative and neuroinflammatory conditions. Here we found that decreased levels of Sirtuin 2 (Sirt2) deacetylase in microglia affects hippocampal synaptic plasticity under inflammatory conditions. The results show that long-term potentiation (LTP) magnitude recorded from hippocampal slices of wild type mice does not differ between those exposed to lipopolysaccharide (LPS), a pro-inflammatory stimulus, or BSA. However, LTP recorded from hippocampal slices of microglial-specific Sirt2 deficient (Sirt2 −) mice was significantly impaired by LPS. Importantly, LTP values were restored by memantine, an antagonist of N-methyl-D-aspartate (NMDA) receptors. These results indicate that microglial Sirt2 prevents NMDA-mediated excitotoxicity in hippocampal slices in response to an inflammatory signal such as LPS. Overall, our data suggest a key-protective role for microglial Sirt2 in mnesic deficits associated with neuroinflammation.

Background: In 2010, changes were made to the shift pattern of neurology residents for cover in the Emergency Department at a university hospital. This resulted in a decrease in the number of emergency hours worked by neurology specialists and allowed for a natural quasi-experiment. Aim: We aimed to evaluate if changes to the number of emergency hours worked by neurology residents and specialist neurologists, (intervention) altered the number or pattern of admitted stroke mimics (SMs). Methods: Observational retrospective study from January 2007 to December 2013. Time of intervention was set as August 2010. We used a segmented linear regression - ARIMA - to evaluate changes in the temporal pattern of admitted SMs. A statistical correlation between the number of emergency hours worked by neurology residents and the number of admitted SMs was calculated using the Pearson Correlation Coefficient. Results: Of the 2,552 patients admitted to the stroke unit, 290 were SMs (11.4%). After August 2010, there was an increase in the number of admitted SMs (p = 0.003). After 2010, the most frequent SM diagnosis changed from a psychiatric condition to peripheral vertigo. A positive correlation was found between the number of hours worked primarily by neurology residents and the number of admitted SMs (Pearson correlation coefficient = 0.94; p = 0.002). Conclusions: Changes in the pattern of Emergency Department shifts were associated with an increase in the rate of admitted SMs and with a higher number of mimics with a final diagnosis of peripheral vertigo.