Predator odors are non-intrusive natural stressors of high ethological relevance. The objective of this study was to investigate the processing of a chronic, life-threatening stimulus during repeated prolonged presentation to Brandts voles. One hundred and twenty voles were tested by repeated presentation of cat feces in a defensive withdrawal apparatus. Voles exposed to feces for short periods showed more avoidance, more concealment in the hide box, less contact time with the odor source, more freezing behavior, less grooming, more jumping, and more vigilant rearing than did non-exposed voles, and those exposed for longer periods. Serum levels of adrenocorticotropic hormone and corticosterone increased significantly when animals were repeatedly exposed to cat feces for short periods. The behavioral and endocrine responses habituated during prolonged presentation of cat feces. ?fosB mRNA expression level was highest in voles exposed to cat feces for 6 and 12 consecutive days, and subsequently declined in animals exposed to cat feces for 24days. We therefore conclude that the behavioral and endocrine responses to repeated exposure to cat feces undergo a process of habituation, while ?fosB changes in the medial hypothalamic region exhibit sensitization. We propose that habituation and sensitization are complementary rather than contradictory processes that occur in the same individual upon repeated presentation of the same stressor.
Predator odors are non-intrusive natural stressors of high ethological relevance. Animals are daily challenged with stressors of varying intensity and it is essential for their survival to respond to a wide range of threats. Behavioral and hormonal responses and changes in the level of medial hypothalamic c-fos mRNA were examined in Brandts voles (Lasiopodomys brandtii) exposed to the feces of a domestic cat (Felis catus) stored for different periods. One hundred voles were tested in the defensive withdrawal apparatus. The voles showed an aversion to freshly collected cat feces, indicated by high levels of flight-related behaviors, increased freezing behavior, and more vigilant rearing compared to old feces. The serum levels of adrenocorticotropic hormone and corticosterone significantly increased when the voles were exposed to fresh cat feces. The level of c-fos mRNA in the medial hypothalamic region was highest in the individuals exposed to fresh cat feces. All of these behavioral, endocrine and c-fos-mRNA responses were lower when voles were subjected to older cat feces. We conclude that these responses depend on volatile chemical constituents of cat feces rather than their physical characteristics and that this accounts for the lower responses to feces stored for longer periods.
The objectives of the study are to analyze the clinical and pathological features of 35 Chinese patients with late onset lupus nephritis (LN) in a single center. All the LN patients followed-up in our lupus clinic center from 1986 to 2008 were enrolled in this retrospective study. Thirty-five patients with a disease onset beyond the age of 50 years were identified. One hundred systemic lupus erythematosus (SLE) patients who had their disease onset before the age of 50 years were randomly recruited as controls. All of them received renal biopsy. The histological classifications were categorized according to 2003 International Society of Nephrology/Renal Pathology Society (ISN/RPS) classification. All of patients were Han Chinese. The mean age of onset of SLE for late onset and the control groups were 55.7 ± 6.5 years (range: 50-76) and 28.9 ± 7.6 years (range:18-48).The female to male ratio was smaller in the late onset SLE group, 2.9-1, compared with 7.3-1 in the control. The patients with hypertension in late onset LN were much more than that in control group. The renal histological classes showed no significant difference between the two groups. Classes IV, V, IV + V were common in late onset LN patients. There were no significant differences in extra renal manifestations except for a lower prevalence of malar rash, a higher leukopenia and skin vasculitis in the late onset patients. As to the immunological features, serum antineutrophil cytoplasmic antibodies (ANCA) and SSA positivity were more common in late onset LN patients. The patients with hypertension in late onset LN were much more than that in control group. The renal histological classes showed no significant difference between the two groups. Leukopenia and serum ANCA were more common. The results suggest a more severity of the disease in late onset LN.
Interleukin-22 (IL-22), an IL-10 family cytokine, mediates the crosstalk between leukocytes and epithelial cells. Previous studies reported that IL-22 expresses in mouse brain, and the rat PC12 cells are responsive to IL-22 stimulation. However, the biological roles of IL-22 in neuronal cells remain largely unknown. We show here that IL-22 activates Stat3, p38 mitogen-activated protein kinases (MAPK), and Akt pathways and inhibits Erk/MAPK pathway in naïve PC12 cells. We further demonstrate that IL-22 protects naïve PC12 cells from serum starvation-induced cell death via the Jak1/Stat3 and Akt pathways. We also show that IL-22 has no effects on naïve PC12 cell proliferation and cannot protect naïve PC12 cells from 1-methyl-4-phenylpyridinium (MPP(+))-induced cytotoxicity. However, IL-22 exerts a dose-dependent protective effect on MPP(+)-induced neurodegeneration in nerve growth factor-differentiated PC12 cells. Overall, our data suggest that IL-22 might play a role in neurological processes. To our knowledge, this is the first report showing that IL-22 confers a neuroprotective function, which may provide a new therapeutic option for treatment of neurodegenerative diseases.
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