Prolonged anoxia can cause permanent damage to synaptic transmission in the mammalian CNS. We tested the hypothesis that lack of glucose is the major cause of irreversible anoxic transmission damage, and that anoxic synaptic transmission damage could be prevented by glycolysis in rat hippocampal slices. The evoked population spike (PS) was extracellularly recorded in the CA1 pyramidal cell laye...

Mammalian neurons are anoxia sensitive and rapidly undergo excitotoxic cell death when deprived of oxygen, mediated largely by Ca(2+) entry through over-activation of N-methyl-d-aspartate receptors (NMDARs). This does not occur in neurons of the anoxia-tolerant western painted turtle, where a decrease in NMDAR currents is observed with anoxia. This decrease is dependent on a modest rise in cyto...

Turtles of the genus Trachemys show a remarkable ability to survive prolonged anoxia. This is achieved by a strong metabolic depression, redistribution of blood flow and high levels of antioxidant defence. To understand whether nitric oxide (NO), a major regulator of vasodilatation and oxygen consumption, may be involved in the adaptive response of Trachemys to anoxia, we measured NO metabolite...

Oxygen depletion can lead to the collapse of benthic ecosystems, i.e. to dead zones, and large-scale biodiversity loss. Based on mortality and survival, we evaluated ranges of sensitivity and tolerance to hypoxia levels, duration of anoxia and H2S exposure across taxa and key life habits. Experiments were conducted on a sublittoral soft-bottom under realistic in situ conditions in a community s...

In the brain, oxygen is required for both the synthesis and the degradation of monoamine transmitters, so monoaminergic systems can be expected to be strongly affected by anoxia. However, crucian carp {Carassius carassius L.) may survive anoxia for many days or even weeks. In the present study, crucian carp were exposed to anoxia for 22, 76, and 160 h at 8°C. All survived and were found to excr...

The activation of the oxidative metabolism in plants under low oxygen conditions has prompted controversial views. The presence of a ROS component in the transcriptome in response to low oxygen has been observed and an overlap with heat stress has been proved. It has been also demonstrated that ROS are produced during both anoxia and heat, but the site of their production remain contentious. Me...

The present study was undertaken to determine whether vacuolar H+-pyrophosphatase (V-PPase) might replace vacuolar H+-ATPase under energy stress due to anoxia or chilling in anoxia-tolerant species such as rice (Oryza sativa L.) and corn (Zea mays L.). The relative transcript level of V-PPase in rice seedlings, like that of alcohol dehydrogenase 1, increased greatly under anoxia and declined ag...

Oxygen, an essential nutrient, is sensed by a multiple of cellular pathways that facilitate the responses to and survival of oxygen deprivation. The Caenorhabditis elegans embryo exposed to severe oxygen deprivation (anoxia) enters a state of suspended animation in which cell cycle progression reversibly arrests at specific stages. The mechanisms regulating interphase, prophase, or metaphase ar...

Many aerobic organisms encounter oxygen-deprived environments and thus must have adaptive mechanisms to survive such stress. It is important to understand how mitochondria respond to oxygen deprivation given the critical role they play in using oxygen to generate cellular energy. Here we examine mitochondrial stress response in C. elegans, which adapt to extreme oxygen deprivation (anoxia, less...

The extreme anoxia-tolerance of freshwater turtles under cold conditions is well documented, but little is known about their cardiac performance in such situations. Using chronic catheterization techniques, we measured systemic cardiac power output (PO(sys)), systemic cardiac output (Q(.)(sys)), heart rate (fh), systemic stroke volume (V(s,sys)), systemic resistance (R(sys)) and mean arterial p...