title: A simple method for fast temperature changes and its application to thermal activation of TRPV1 ion channels.
abstract: BACKGROUND
  Thermally activated ion channels function as molecular thermometers and participate in other physiological important functions. The mechanism by which they acquire their exquisite temperature sensitivity is unknown and is currently an area of intense research. For this reason, there is a need for diverse methods to deliver controlled temperature stimuli.
  
  
  METHODS
  We have developed a simple, inexpensive and reliable method to deliver temperature pulses to small volumes surrounding the recording area, which can be either a patch-clamp pipette containing a cell-free membrane with thermally activated channels or a whole cell attached to a pipette.
  
  
  RESULTS
  Here we developed a micro-heater based on resistive heating of a copper filament enclosed in a glass capillary that is capable of delivering fast and localized temperature changes. We validated the performance of the micro-heaters by analyzing the heat-induced activation of TRPV1 thermoTRP channels recorded in inside-out patches and demonstrate the use of the micro-heaters.
  
  
  CONCLUSIONS
  The micro-heaters we introduce here are compact, easy to fabricate and to operate. In contrast with bulk solution heaters commercially available, our method is extremely affordable and simple to operate. To the best of our knowledge there are no other similar, commercially available heating methods.
  
  
  CONCLUSIONS
  The micro-heater method is simple and should provide a straightforward and rapid experimental tool to study mechanisms in thermally activated ion channels.
authors: Departamento de Fisiología, Facultad de Medicina, Universidad Nacional Autónoma de México (UNAM), México City 04510, Mexico. Electronic address: leon.islas@gmail.com.
authors: León D
authors: LD
authors: Islas
authors: Departamento de Fisiología, Facultad de Medicina, Universidad Nacional Autónoma de México (UNAM), México City 04510, Mexico.
authors: Victor
authors: V
authors: De-la-Rosa
authors: Departamento de Fisiología, Facultad de Medicina, Universidad Nacional Autónoma de México (UNAM), México City 04510, Mexico.
authors: Beatriz
authors: B
authors: Rodríguez-Cortés
authors: Departamento de Fisiología, Facultad de Medicina, Universidad Nacional Autónoma de México (UNAM), México City 04510, Mexico.
authors: Gisela E
authors: GE
authors: Rangel-Yescas
authors: Sección de Bioelectrónica, CINVESTAV-IPN, México City 07360, Mexico.
authors: David
authors: D
authors: Elias-Viñas
mesh_terms: D000818:Animals; D003198:Computer Simulation; D003300:Copper; D055615:Electrical Equipment and Supplies; D004573:Electrolytes; D004867:Equipment Design; D005898:Glass; D057809:HEK293 Cells; D006801:Humans; D008564:Membrane Potentials / Q000502:physiology; D008962:Models, Theoretical; D018408:Patch-Clamp Techniques / Q000295:instrumentation / Q000379:methods*; D010812:Physical Stimulation / Q000295:instrumentation / Q000379:methods*; D051381:Rats; D012996:Solutions; D050916:TRPV Cation Channels / Q000235:genetics / Q000378:metabolism*; D013696:Temperature; D014162:Transfection
chemical_list: D004573:Electrolytes; D012996:Solutions; D050916:TRPV Cation Channels; C493922:Trpv1 protein, rat; D003300:Copper
keywords: Heat activation; Ion channels; Patch-clamp; Resistive heating; TRPV1 channel; ThermoTRPs