Neuroprotectants attenuate hypobaric hypoxia-induced brain injuries in cynomolgus monkeys

Hypobaric hypoxia (HH) exposure can cause serious brain injury as well as life-threatening cerebral edema in severe cases. Previous studies on the mechanisms of HH-induced brain injury have been conducted primarily using non-primate animal models that are genetically distant to humans, thus hindering the development of disease treatment. Here, we report that cynomolgus monkeys (Macaca fascicularis) exposed to acute HH developed human-like HH syndrome involving severe brain injury and abnormal behavior. Transcriptome profiling of white blood cells and brain tissue from monkeys exposed to increasing altitude revealed the central role of the HIF-1 and other novel signaling pathways, such as the vitamin D receptor (VDR) signaling pathway, in co-regulating HH-induced inflammation processes. We also observed profound transcriptomic alterations in brains after exposure to acute HH, including the activation of angiogenesis and impairment of aerobic respiration and protein folding processes, which likely underlie the pathological effects of HH-induced brain injury. Administration of progesterone (PROG) and steroid neuroprotectant 5α-androst-3β,5,6β-triol (TRIOL) significantly attenuated brain injuries and rescued the transcriptomic changes induced by acute HH. Functional investigation of the affected genes suggested that these two neuroprotectants protect the brain by targeting different pathways, with PROG enhancing erythropoiesis and TRIOL suppressing glutamate-induced excitotoxicity. Thus, this study advances our understanding of the pathology induced by acute HH and provides potential compounds for the development of neuroprotectant drugs for therapeutic treatment.

Spatial and temporal patterns of amphibian species richness on Tianping Mountain,Hunan Province,China

DEAR EDITOR,Exploring species richness patterns across space and time can help in understanding species distribution and in formulating conservation strategies.Among taxa,amphibians are of utmost importance as they are highly sensitive to environmental changes due to their unique life histories(Zhong et al.,2018).Here,we investigated the spatial and temporal patterns of amphibian species richness on Tianping Mountain in China.Specifically,we established 10 transects at low to high elevations,and sampled amphibians in April,June,August,and October 2017.Our results demonstrated that amphibian species composition and richness varied significantly at both spatial and temporal scales and were associated with gradients of environmental change in microhabitats on Tianping Mountain.

Author Correction: Neuroprotectants attenuate hypobaric hypoxia-induced brain injuries in cynomolgus monkeys

Open Access This is an open-access article distributed under the terms of theCreative Commons Attribution Non-Commercial License(http:1/creativecommons.org/licenses/by-nc/4.0/).which permits unrestrictednon-commercial use,distribution.and reproduction in any medium.

Spatiotemporal patterns of anuran functional diversity in temperate montane forests

Functional diversity is an integrative approach to better understand biodiversity across space and time.In the present study,we investigated the spatiotemporal patterns(i.e.,elevation and season)and environmental determinants of anuran functional diversity on Tianping Mountain,northwest Hunan,China.Specifically,10 transects were established from low(300 m a.s.l.)to high(1492 m a.s.l.)elevations,and anuran communities were sampled in spring,early summer,midsummer,and autumn in 2017.Four functional diversity indices were computed for each transect in each season using ecomorphological functional traits.Our results demonstrated that these indices had contrasting responses to increasing elevations.However,they did not differ significantly among seasons in terms of temporal patterns.Interestingly,the unique spatiotemporal functional diversity patterns were impacted by distinct environmental variables,such as leaf litter cover,water temperature,number of trees,and water conductivity.