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R4831 --> Intermittent Hypoxia (IH) is a well‐recognized trait of untreated sleep apnea. We have recently demonstrated that mitigating oxidative stress induced by IH prevents impairments to hippocampal NMDAr‐dependent LTP, hippocampal adult neurogenesis, spatial learning and memory. As these processes are also dependent on metabolic activity, the changes of metabolism caused by IH could also contribute to the impairment of synaptic plasticity and adult neurogenesis. The objective of this on‐going study is to assess mitochondrial respiration in hippocampal tissue after ten days of IH (IH10). We assessed hippocampal mitochondrial respiration using Seahorse XF24 Extracellular Flux Analyzer technology. The tissue biopsies (Diameter: 1mm, thickness: 350 μm) were prepared from hippocampal brain slices originating from control mice or mice exposed to IH10. Preliminary experiments indicate that the basal O2 consumption rate (OCR) tended to decrease in IH10 (control: 202 ± 15 pmol/min, n=8 vs. IH: 126 ± 39 pmol/min n=4, P=0.05) and maximal OCR induced by FCCP was decreased in IH10 (control: 278 ± 29 pmol/min vs. IH10: 126 ± 39 pmol/min, P<0.05). These findings suggest IH impaired mitochondrial function in the hippocampus. ATP‐linked OCR induced by oligomycin and proton leak were not altered by IH10. Interestingly, the proportion of non‑mitochondrial OCR in control was smaller than IH10 (control: 13 ± 1 % vs. IH10: 20 ± 5 %, P<0.05). Such a difference in non‐mitochondrial OCR may reflect a state favoring enhanced reactive oxygen species production independent of mitochondrial origin. In conclusion, our study provides greater insights into the molecular basis by which untreated sleep apnea accelerates neurodegeneration in conditions such as Alzheimer's disease. [ABSTRACT FROM AUTHOR]

Around the world and across taxa, subterranean mammals show remarkable convergent evolution in morphology (e.g., reduced external ears, small eyes, shortened limbs and tails). This is true of sensory systems as well (e.g., loss of object vision and high frequency hearing). The naked mole-rat (Heterocephalus glaber) displays these typical subterranean features, but also has unusual characteristics even among subterranean mammals. Naked mole-rats are cold-blooded, completely furless, very long-lived (> 30 years), and eusocial (like termites). They also live in large colonies, which is very unusual for subterraneans. Their cortical organization has reduced area for visual processing, utilizing 30% more cortex for tactile processing. They are extremely tolerant to oxygen deprivation, and can recover from 18 min of anoxia. Their pain pathway is reduced and they feel no pain from acidosis. They are the only rodent tested to date whose pheromone-detecting vomeronasal organ shows no postnatal growth. These features may be a result of this species' "extreme subterranean lifestyle" that combines living underground and living in large colonies. Many respiring animals cramped together in unventilated burrows elevates CO 2 levels, high enough to cause acidosis pain, and depletes O 2 concentrations low enough to kill other mammals. The naked mole-rat may be an extreme model of adaptation to subterranean life and provides insights into the complex interplay of evolutionary adaptations to the constraints of subterranean living. Anat Rec, 2018. © 2018 American Association for Anatomy., (© 2018 American Association for Anatomy.)