RT Journal Article SR Electronic T1 Protective effect of hypothermia on brain potassium homeostasis during repetitive anoxia in Drosophila melanogaster JF The Journal of Experimental Biology JO J. Exp. Biol. FD The Company of Biologists Ltd SP 4157 OP 4165 DO 10.1242/jeb.074468 VO 215 IS 23 A1 Rodríguez, Esteban C. A1 Robertson, R. Meldrum YR 2012 UL http://jeb.biologists.org/content/215/23/4157.abstract AB Oxygen deprivation in nervous tissue depolarizes cell membranes, increasing extracellular potassium concentration ([K+]o). Thus, [K+]o can be used to assess neural failure. The effect of temperature (17, 23 or 29°C) on the maintenance of brain [K+]o homeostasis in male Drosophila melanogaster (w1118) individuals was assessed during repeated anoxic comas induced by N2 gas. Brain [K+]o was continuously monitored using K+-sensitive microelectrodes while body temperature was changed using a thermoelectric cooler (TEC). Repetitive anoxia resulted in a loss of the ability to maintain [K+]o baseline at 6.6±0.3 mmol l−1. The total [K+]o baseline variation (Δ[K+]o) was stabilized at 17°C (−1.1±1.3 mmol l−1), mildly rose at 23°C (17.3±1.4 mmol l−1), and considerably increased at 29°C (332.7±83.0 mmol l−1). We conclude that (1) reperfusion patterns consisting of long anoxia, short normoxia and high cycle frequency increase disruption of brain [K+]o baseline maintenance, and (2) hypothermia has a protective effect on brain K+ homeostasis during repetitive anoxia. Male flies are suggested as a useful model for examining deleterious consequences of O2 reperfusion with possible application for therapeutic treatment of stroke or heart attack. ADanoxic depolarization[K+]iintracellular potassium concentration[K+]oextracellular potassium concentrationΔ[K+]ototal [K+]o baseline variationMRmetabolic ratePORpercentage of recoveryΔPORtotal percentage of recovery variationRNSreactive nitrogen speciesROSreactive oxygen speciesSDspreading depressionTECthermoelectric coolertrecoverytime to recoverytsurgetime to surge