Figure 1From: The acute neurotoxicity of mefloquine may be mediated through a disruption of calcium homeostasis and ER function in vitroEffects of mefloquine on ER calcium homeostasis. The effects of mefloquine on cytoplasmic calcium levels in rat neurons were investigated using confocal microscopy. Neurons were loaded with the calcium-sensitive dye Fluo-3 that was replaced with low-calcium Locke's buffer after 1 h. The neurons were scanned at 10 s intervals to measure baseline fluorescence prior to the addition of DMSO (0.2%) or mefloquine (Mef, 80 μM) followed by thapsigargin (Thaps, 1 μM). Arrows indicate additions after scans 2 and 37, respectively. Mefloquine increased cytoplasmic calcium and antagonized the pharmacological action of thapsigargin, suggesting that the drug mobilizes the ER calcium store. The lack of a subsequent glutamate response (Glu, 1 μM after scan 63) demonstrates the external medium was substantially devoid of free calcium, whilst the presence of a subsequent CaCl2 (1.6 mM after scan 67) response indicates that the neurons remain viable at the termination of the experiment.Back to article page