HEMATOLOGIC REFERENCE INTEVALS FOR SPIDER MONKEYS (ATELES GEOFFROYI) IN MANAGED CARE WITH RESPECT TO SEX AND AGE.

The determination of health status in spider monkeys (Ateles geoffroyi) that are held in managed care requires periodic evaluation. The present study obtained baseline data on hematologic values, body weight, and length in A. geoffroyi. A total of 118 individuals from three housing centers were included in the study and grouped into two categories by age (92 adults, 26 juveniles) and sex (46 males, 72 females). Body weight, red blood cell (RBC) counts, and hemoglobin counts were significantly higher in adult males than in adult females. No differences in length were found between sex and age groups. The present findings indicate that hematologic values by age and sex in A. geoffroyi are similar to those reported in other spider monkey populations in both managed care and the wild. These results will be useful as a reference for young individuals and adults in future studies of the health of this species.

Does lipopolysaccharide-based neuroinflammation induce microglia polarization?

Lipopolysaccharide (LPS) is a potent immunogen when administered locally and/or systemically. The peripheral immunization with LPS could contribute to the progression of neurological diseases because a strong link between neuroinflammation and dopaminergic degeneration has been found. The switch between the survival and neuronal death in substantia nigra could be related to M1 (neurotoxic) and M2 (neuroprotective) microglia phenotypes. In this review, we present the current findings about microglia roles, biomarkers, and natural or synthetic immune modulators determined in the LPS-based murine model.

Lipopolysaccharide-based endotoxemia produce toxicity in peripheral organs and microglia migration in a dose-dependent manner in rat substantia nigra.

The peripheral inflammatory stimulus could induce cell damage in peripheral organs and activate microglial cells in the brain. One such stimulus was given to adult male Wistar rats by injecting different concentrations of lipopolysaccharide (LPS; 50, 300, 500 g/kg and 5 mg/kg i.p.). To verify the systemic effect of the LPS administration, the serum content of C-reactive protein (CRP), the variation of body weight and cellular changes in the spleen, liver and kidney were determined. Motor impairment was evaluated by rotarod and open field tests. Microglia activation and dopaminergic degeneration was confirmed by immunolabelling for CD11b/c (microglia) and tyrosine hydroxylase (TH), respectively. The cell counting was performed in substantia nigra pars compacta (SNpc), microglial activation was explored in SNpc, substantia nigra pars reticulata (SNpr), substantia nigra pars compacta dorsal (SNcd) and the ventral tegmental area (VTA). For the statistical analysis, one-way ANOVA followed by Tukey post hoc test (p ≤ 0.05) was used. On day 7 post intraperitoneal administration of LPS, cellular atrophy was detected in the liver, kidney and spleen at 5 mg/kg, without significant changes in CRP levels. Body weight loss and motor impairment was present only on day 1 post LPS administration. The dosage of 500 g/kg and 5 mg/kg of LPS caused the loss of dopaminergic neurons (40%) in SNpc and microglia migration in a dose-dependent manner in SNcd, SNpc and SNpr. LPS-induced endotoxemia favours damage to the peripheral organs and microglial migration in a dose-dependent manner in rat substantia nigra.