Comparative Effects of Heterologous TRPV1 and TRPM8 Expression in Rat Hippocampal Neurons
Figure 5
Agonist-induced toxicity in transfected neurons.
(A) An example TRPV1-transfected neuron designated “unhealthy” (arrow) in the same field as a “healthy” non-transfected neuron (arrowhead). Syn-YFP fluorescence (left panel) and phase contrast (right panel) images are shown. Note the swollen cell body of the unhealthy cell. Scale bar represents 30 µm. (B) Transfected neurons treated 4 hr with 500 nM capsaicin, 25 µM D-APV, and 1 µM NBQX in culture media with (2 mM) or without (0 mM plus 500 µM EGTA) calcium were assessed as “healthy” or “unhealthy” by a naïve observer. Significantly fewer TRPV1-transfected neurons treated in calcium were healthy than either YFP-transfected neurons treated in calcium or TRPV1-transfected neurons treated without calcium (ANOVA, p<0.01; post hoc Tukey test, p<0.05). (C) Transfected neurons treated 4 hr with 100 µM menthol, 25 µM D-APV, and 1 µM NBQX in culture media with or without calcium were assessed as “healthy” or “unhealthy” as in (B). There was no significant change in health of TRPM8-transfected neurons compared to YFP-transfected neurons regardless of whether or not they were exposed to extracellular calcium. Error bars represent SEM.
