Apoptosis and Extracellular ATP Concentration. Proportion of Caspase 3 positive cells post-heat shock, MLO-Y4 osteocytes and B35 neurons combined (left). Relative concentration of ATP in cell medium from both sides of the device (heated and unheated) after 1,6, and 12 h, normalized by unheated control within the Mμn at respective timepoints for both MLO-Y4 osteocytes and B35 neurons respectively (right). *indicates significant difference from unheated control. # indicates significant difference from opposing side of the Mμn post-heat shock, p < 0.05