Open field test

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Small, round open field test box with relatively few fields

The open field test (roughly translated: test in open terrain ) is an internationally widespread, but only moderately standardized test arrangement for the quantitative representation of the exploratory behavior of test animals. The test was initially developed for rats , but was soon also used in mice . The open-field test is also used to that as humans fear designated avoidance measure of test animals; The measure of the excitement of the test animal is the number of dung balls.

With the help of open-field tests, differences between breeding lines and - within the breeding lines - between the sexes can be shown quantitatively. Furthermore, the calming, stimulating or anxiety-relieving effect of medication, alcohol and other drugs as well as hormones can be tested. More recently, the behavior of genetically modified animals has been tested in comparison with non-modified animals of the same origin.

methodology

The open field test is based on the behavioral observation that mice, rats, chicks and many other animals avoid entering an unknown, brightly lit open area that does not provide them with any cover or other forms of retreat. If they are nevertheless exposed in such an environment, their activity will move in the area of ​​tension between fearfulness, willingness to flee and exploration.

Open-field tests take place in a white plastic container, usually open at the top, with a floor space of approximately 1 meter × 1 meter. The base, which can also consist of a round container, is usually divided into 25 or 36 squares. Brightness, ambient noise and room temperature as well as all other possible influencing factors must be kept constant. After a test animal has been placed either in a corner, in the center or in a specific square (depending on the test program), all behaviors and all changes of location are recorded in a behavior log over a defined period of time and in their chronological order . Then, for example, the frequency of occurrence of each behavior, the distance covered in the test site, the speed of movement and the frequency with which certain areas (preferred squares, proximity to the outer wall) were visited, can also be calculated depending on the duration of the Stay in the test arrangement.

Since the animals get used to the new environment after a few minutes despite all the aversive stimuli , this test can only be carried out once for each animal. However, repetitions allow conclusions to be drawn about their memory . A single test often only takes five minutes; Depending on the question, it can be extended to 15 minutes and more. The longer an individual test takes, the more precisely those changes in behavior are recorded that can be interpreted as signs of habituation.

See also

literature

  • Todd D. Gould et al .: The Open Field Test. In: Mood and Anxiety Related Phenotypes in Mice. Volume 42 of the Neuromethods series , 2009, pp. 1-20, doi : 10.1007 / 978-1-60761-303-9_1
  • P. Koene et al .: The open-field: test of emotionality or an approach-avoidance conflict? In: Proceedings of the 37th International Congress of the ISAE. Brescia, Italy, June 24-28, 2003, Fondazione Iniziative Zooprofilattiche e Zootecniche, p. 86 ( full text (PDF) )
  • A. Ramos and P. Mormède (1998): Stress and emotionality: a multidimensional and genetic approach. In: Neurosci. Biobehav. Rev. Volume 22, 1998, pp. 33-57, doi : 10.1016 / S0149-7634 (97) 00001-8 PMID 9491939 .

Web links

Example of an Open Field Test ( Memento of October 24, 2007 on the Internet Archive ) ( University of Cincinnati )

Individual evidence

  1. ^ C. S Hall: Emotional behavior in the rat. I. Defecation and urination as measures of individual differences in emotionality. In: Journal of Comparative Psychology. Volume 18, No. 3, 1943, pp. 385-403
  2. ^ Victor H. Denenberg: Open-field Behavior in the Rat: What Does it Mean? In: Annals of the New York Academy of Sciences. Volume 159, 1969, pp. 852-859 (= Experimental Approaches to the Study of Emotional Behavior. ), Doi: 10.1111 / j.1749-6632.1969.tb12983.x
  3. ^ Nigel W. Bond and Eros L. di Giusto: Effects of prenatal alcohol consumption on open-field behavior and alcohol preference in rats. In: Psychopharmacologia. Volume 46, No. 2, 1976, pp. 163-165, doi: 10.1007 / BF00421386
  4. ↑ NN Barykina et al .: Effects of thyroid hormone deficiency on behavior in rat strains with different predisposition to catalepsy. In: Physiology & Behavior. Volume 75, No. 5, 2002, pp. 733-737, doi: 10.1016 / S0031-9384 (02) 00662-5
  5. ↑ for example: Dominguez et al .: Phenotypical and biochemical analysis of BACE1 and BACE2 deficient mice. On: www.jbc.org , 2005 (PDF; 3.4 MB)