Fig. 5.

Hypothermia reduced ryanodine receptor-mediated Ca²⁺ induced Ca²⁺ release. (A) Prior to caffeine-mediated RyR stimulation, baseline 340/380 ratio values from both treatment groups were not significantly different with values of 0.28±0.01 in the 31°C group and 0.34±0.01 in the 37°C group (black bars). Upon stimulation with 37°C caffeine, 340/380 ratios peaked to 0.72±0.05. When stimulated with 31°C caffeine, neurons exhibited a diminished response with a peak ratio of 0.44±0.04 (grey bars). *P<0.001 compared to 37°C baseline, **P<0.05 compared to 37°C baseline, #P<0.001 between 31°C and 37°C peaks, one way ANOVA followed by post-hoc Tukey test, n=10 plates per group. (B) Representative pseudocolor images obtained from baseline neuron (left panel), neuron stimulated with 37°C caffeine (top right panel), and neuron stimulated with 31°C caffeine (bottom right panel). Neurons exhibited elevated [Ca²⁺]_i upon 37°C stimulation and a diminished response to 31°C stimulation.