Cardiovascular function in response to environmental anoxia

Climate warming is leading to the creation and expansion of areas of reduced dissolved oxygen in the marine environment, termed “oceanic dead zones”. As surviving in oxygen limited environments is a challenge for most marine species, the spectacular anoxia (no oxygen) tolerance of the phylogenetically ancient hagfish is particularly interesting and relevant for predicting species persistence in areas that will likely experience reduced environmental oxygen. In this set of studies I discovered, not only that hagfish could persist in anoxia for >36 hr, but I also uncovered a number of diverse cardiovascular and biochemical phenotypes that permit survival in anoxia. These findings provide new insight into cardiovascular function, which has been traditionally viewed as a highly aerobic process.”

Related publications . Wilson CM, Roa JN, Cox GK, Tresguerres M, Farrell AP (2016). A tell-tale heart: The ancestral, anoxia-tolerant hagfish divulges novel heart rate control mechanism. J Exp Biol 219, 3227-3236.

. Gillis TE, Regan MD, Cox GK, Harter TS, Brauner CJ, Richards JG, Farrell AP (2015). Characterizing the metabolic capacity of the anoxic hagfish heart. J Exp Biol 218, 3754-3761.

. Wilson CM, Cox GK, Farrell AP (2014). The beat goes on: Cardiac pacemaking in extreme conditions. J Comp Physiol A. 186: 52-60.

. Farrell AP, Farrell ND, Jourdan H, Cox GK (2012). A perspective on the evolution of the coronary circulation in fishes and the transition to terrestrial life. In Ontogeny and Phylogeny of the Vertebrate Heart (ed. D. Sedmera and T. Wang), pp. 75-102. New York: Springer.

. Cox GK, Sandblom E, Richards JG and Farrell AP (2011). Anoxic survival of the Pacific hagfish (Eptatretus stoutii). J Comp Physiol B. 181, 361-371.

. Cox GK, Sandblom E and Farrell AP (2010). Cardiac responses to anoxia in the Pacific hagfish, Eptatretus stoutii. J Exp Biol 213, 3692-3698.

. Sandblom E, Cox GK, Perry SF and Farrell AP (2009). The role of venous capacitance, circulating catecholamines, and heart rate in the hemodynamic response to increased temperature and hypoxia in the dogfish. Am J Physiol Regulatory Integrative Comp Physiol 296,1547-1556.

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Georgina Cox
Postdoctoral Scholar

My research interests broadly center on cardiovascular responses to physiological and abiotic stress. I use a comparative approach to look for commonalities in how cardiovascular systems in animals that inhabit heterogeneous environments overcome physiological and abiotic stress.