Comparative Effects of Heterologous TRPV1 and TRPM8 Expression in Rat Hippocampal Neurons
Figure 1
TRPV1-transfected neurons respond strongly to the agonist capsaicin.
(A) Fluorescence image of a neuron in mass culture transfected with synaptophysin-YFP (Syn-YFP) and TRPV1. Scale bar denotes 100 µm. (B) Phase contrast image of the same field as (A). (C) Example of a Syn-YFP/TRPV1-transfected neuron recorded in cell-attached patch configuration in voltage-clamp mode during 5 s 500 nM capsaicin application (top trace) or 5 s 30 mM KCl application (bottom trace). Note that action potentials could be elicited by both treatments in the same cell. The suboptimal seal, evident in the slow current excursions, was characteristic of nearly all TRPV1-transfected neurons. (D) Example of a non-transfected neuron recorded under the same conditions as (C). Note that action potentials were only elicited during KCl application. (E) Example of a Syn-YFP/TRPV1-transfected neuron recorded in whole-cell voltage-clamp mode during 10 s acute 500 nM capsaicin or 30 mM KCl application. TRPV1-transfected neurons responded with robust currents to both capsaicin and KCl application. (F) Example of a non-transfected neuron recorded under the same conditions as (E). Non-transfected neurons never responded to capsaicin but always responded with robust KCl-induced currents.
