Direct Assessment of Temperature Sensitivity of the TRPM2 Channel with the Patch Clamp Technique

The transient receptor potential (TRP) family of ion channels contains a large array of receptors of pain, taste, or temperature. Thus far, several TRP channels have been confirmed as warm or cold sensors; however, the exact molecular mechanism of heat detection remains obscure. The methods of investigation of temperature sensitivity involve several different techniques, e.g., in vivo experiments, fluorescence-based Ca²⁺ measurements, and electrophysiology. Here we describe an electrophysiological configuration that allows the direct assessment of the temperature sensitivity of the TRPM2 channel by measuring the temperature dependence of microscopic and macroscopic currents, apparent ligand binding affinities, and the gating parameters of the channel under the precise control of temperature and activating ligand concentrations. The technique described here may be adapted to explore temperature sensitive behavior of various other ion channels.