Does conditioning influence the increase of heart rate and body temperature as provoked by handling in the mouse?

K. Kramer1, A. Mulder2, H. van de Weerd3, V. Baumans3, C. van Heijningen4, R. Remie2, H.P. Voss1 and B. van Zutphen3

1Department of Safety and Environmental Affairs, Free University, Amsterdam, The Netherlands
2Department of Laboratory Animal Science, Solvay Pharmaceuticals b.v., Weesp, The Netherlands
3Department of Laboratory Animal Science, Utrecht University, Utrecht, The Netherlands
4Laboratory for Physiology, ICaR-VU, Free University, Amsterdam, The Netherlands

Animals subjected to various laboratory procedures and environmental changes will react to new situations with changes in their physiological responses. Handling of mice or offering them a new environment such as a new cage with clean bedding results in an acute increase in heart rate (HR) [2,3] and body temperature (BT) [1]. Radio-telemetry with an implantable transmitter provides an accurate and reliable way for obtaining these physiological measurements from awake and freely moving animals in their own environment. Previously we found that the HR of freely moving mice, implanted with an electrocardiogram (ECG) transmitter, increased from 400-450 beats per minute (bpm), measured in their home cages at rest, to 750-800 bpm measured after handling and/or placing the animals in a new cage [2]. BT, also measured with the radio-telemetry technique, increased with 1.5 ºC after handling [1]. HR has been reported as an indicator for animal welfare and stress and has been used as a physiological parameter in testing the conditioned response in rats.

Handling of rats and mice is a common procedure in the laboratory animal house. The purpose of the present study was to investigate whether conditioning of the mouse with an acoustic stimulus (10 kHz, 60 dB), will reduce the effect of handling on HR and BT. Preliminary results seem to indicate that there is no adaptation of the animal to repeated handling, as would be reflected by a decrease of the response of HR and/or BT. Also no evident conditioning effect of the acoustic stimulus could be shown.

References

  1. Clement; J.C., Mills, P; Brockway, B.P. (1989). Use of telemetry to record body temperature and activity in mice. Journal of Pharmacological Methods, 21, 129-140.
  2. Kramer, K.; van Acker, S.A.B.E.; Voss, H.P.; Grimbergen, J.A.; van der Vijgh, W.J.F.; Bast, A. (1993). Use of telemetry to record electrocardiogram and heart rate in freely moving mice. Journal of Pharmacological and Toxicological Methods, 209-215.
  3. Kramer, K. (2000). Aplications and Evaluation of Radio-telemetry in Small Laboratory Animals. Doctoral thesis, Utrecht University. ISBN 90-393-2313-5.

Poster presented at Measuring Behavior 2000, 3rd International Conference on Methods and Techniques in Behavioral Research, 15-18 August 2000, Nijmegen, The Netherlands

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