title: Surgical preparation of mice for recording cardiorespiratory parameters in vivo.
abstract: BACKGROUND
  The explosion in the use of genetically modified mouse strains to investigate function in biology has an enormous potential to expand on pharmacological studies traditionally conducted in rats. A key limitation to date is the inability to record from multiple nerves in an anaesthetised mouse for long periods.
  
  
  METHODS
  Here we describe an in vivo preparation that maintains mice in a suitable physiological state, under anaesthesia, for at least 6 hr and also enables multiple cardiorespiratory recordings over that time.
  
  
  RESULTS
  Using the method described, blood pressure, heart rate, phrenic nerve activity, splanchnic nerve activity and heart rate were able to be recorded for hours in an anaesthetised, paralysed and mechanically ventilated mouse.
  
  
  CONCLUSIONS
  Existing anaesthetised mouse preparations are limited by difficulties in maintaining mice under anaesthesia for long periods. This time constraint therefore limits the surgical time and number of cardiorespiratory variables recorded. It also limits the type of stimuli that can be administered and the length of recorded responses. The method described here optimises these variables to overcome these challenges.
  
  
  CONCLUSIONS
  In summary, we report an approach that enables physiological and pharmacological studies previously undertaken in larger animals or 'reduced' preparations, to be conducted in vivo in mice. We anticipate that the use of this preparation will enable a deeper understanding of genetic variation, and allow a much greater level of phenotypic characterisation in genetically modified mice.
authors: Australian School of Advanced Medicine, 2 Technology Place, Macquarie University, Sydney, NSW 2109, Australia; The Heart Research Institute and The University of Sydney, 7 Eliza St, Newtown 2042, Australia. Electronic address: melissa.farnham@hri.org.au.
authors: Melissa M J
authors: MM
authors: Farnham
authors: Department of Physiology and Pharmacology, Hotchkiss Brain Institute and Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, 3330 Hospital Dr. N.W., Calgary, Alberta T2N4N1, Canada.
authors: Edward T
authors: ET
authors: O'Connor
authors: Department of Physiology and Pharmacology, Hotchkiss Brain Institute and Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, 3330 Hospital Dr. N.W., Calgary, Alberta T2N4N1, Canada.
authors: Richard J A
authors: RJ
authors: Wilson
authors: The Heart Research Institute and The University of Sydney, 7 Eliza St, Newtown 2042, Australia.
authors: Paul M
authors: PM
authors: Pilowsky
mesh_terms: D000758:Anesthesia / Q000379:methods*; D000818:Animals; D001784:Blood Gas Analysis; D001794:Blood Pressure; D002404:Catheterization; D004594:Electrophysiology / Q000379:methods*; D005260:Female; D006339:Heart Rate; D051379:Mice; D018345:Mice, Knockout; D008839:Microelectrodes; D023421:Models, Animal; D009407:Nerve Block; D010791:Phrenic Nerve; D012121:Respiration, Artificial / Q000379:methods*; D013153:Splanchnic Nerves; D013514:Surgical Procedures, Operative / Q000379:methods*; D050916:TRPV Cation Channels / Q000235:genetics / Q000378:metabolism; D013997:Time Factors
chemical_list: D050916:TRPV Cation Channels; C493921:TRPV1 protein, mouse
keywords: Anaesthesia; Blood pressure; Phrenic nerve; Sympathetic nerve activity; Ventilation