General Health & Activity Levels

Several customized behavioral tests are offered to phenotype mouse and rat models and evaluate effects of compounds in different in vivo models.

New behavioral tests are continuously developed and validated.

Irwin Test

The Irwin test is a general health check for rodentsThe Irwin test is a general health check for rodents.

Using the Irwin test in mice, physical characteristics and conspicuities, sensorimotor reflexes and motor abilities will be checked by an experienced observer.

Physical characteristics:

  • Body weight
  • Body temperature
  • Existence of whiskers
  • Constitution of the fur and eyes
  • Individual remarks (e.g. bites or other lesions)

Sensorimotor reflexes:

  • Whiskers-orienting reflex
  • Righting reflex
  • Ear twitch reflex
  • Eye blink reflex
  • Pupillary reflex

Motor abilities:

  • Vertical pole test
  • Wire suspension test

Using the Irwin test in rats, physical characteristics and sensorimotor reflexes are measured as in mice (see above).

Additionally rats are tested in the following tests:

  • Inclined layer test (tilted platform test, balance)
  • grasping reflex (sensorimotor reflex)
  • chimney test (spatial orientation)
  • cliff hanging (muscle strength)

Irwin Test figureBody weight of 6-month old 5xFAD transgenic mice. Body weights separated by sex. 5xFAD: n = 12 (6 male and 6 female); nTg: n = 12 (6 male and 6 female). Mean +SEM. T-test. **p<0.01; ***p<0.001.

Nest Building Test

Nesting behavior is a simple and versatile behavioral test suitable for the evaluation of motor deficits. Nest building is an intrinsic behavior performed by male and female rodents that requires fine motor skills.

Nest Building Behavior Mice

To test the individual Nest Building Behavior, mice are individually housed in cages containing wood chip bedding and one square of pressed cotton (`nestlet´). No other nesting material (e.g. wood wool) is provided. The following morning the manipulation of the nestlet and the constitution of the built nest are assessed manually according to a five-point scale.

Nest buliding behavior figureNest building behavior in 2-, 3- and 6-month old Line 61 α-Synuclein transgenic mice compared to non-transgenic littermates. Tg: n = 13-15, nTg: n = 11-15; *** p<0.001; Data are shown as mean + SEM. Two way ANOVA, Bonferroni’s posthoc test.

 

 

 

 

 

Nest buliding behavior

Nest Building Behavior Rats

The ability of rats to build nests is assessed by offering the animals sterile nesting material that is placed into the metal grid next to the food pellets.

In the evening, rats are provided with nesting material. The following morning, the quantitative amount of nesting material that was actively pulled into the cage, as well as the quality of the nest is assessed. The unused nesting material is thus weighed and recorded, and photographs of the nests are taken and analyzed manually by an experienced experimenter.

Open Field Test

Open field imageThe Open Field Test is used to analyse rodents for changes in activity and anxiety.

A Plexiglas Open Field (TSE-System®) is used to test the activity of rodents. Infrared photo beams detect movements on the ground but also rearing (standing on the hind paws). Testing is performed under standard room lighting conditions in naïve animals. The number of fecal boli is counted as measure of emotionality. A tracking system automatically measures the activity, hyperactivity, rearing, thigmotaxis, and distance traversed. Only the amount of fecal boli is measured manually.

Open field behavior of MK-801 treated C57Bl/6 mice. Left graph represents the distance traversed of MK801 treated animals compared to sham treated controls.Open field behavior of MK-801 treated C57Bl/6 mice. Left graph represents the distance traversed of MK801 treated animals compared to sham treated controls. MK801 treated mice show increased locomotion starting 20 minutes after treatment. Right graph represents the hyperactivity level of MK801 treated animals compared to sham treated controls. MK801 treated mice show increased hyperactivity level starting 20 minutes after treatment. Data are shown as mean ± SEM. Two way ANOVA. **p<0.01;***p<0.001.

 

Poke Hole Test

Poke Hole test imageThe hole-board apparatus offers a simple method of measuring the responses of a rodent to a novel environment. Hole-board exploration takes advantage of the curious nature of rodents and their tendency to poke their noses into holes.

The investigation of curiosity behavior is performed in open field boxes. Nose pokes into a hole interrupt the infrared beams just below the edge of each hole. Number and duration of the nose pokes are automatically calculated for each animal during a defined period. The latency to the first nose poke is also measured.

Poke Hole Test of 5-8-month old TMHT Tau transgenic mice. Latency to poke the nose into a hole in secondsPoke Hole Test of 5-8-month old TMHT Tau transgenic mice. Latency to poke the nose into a hole in seconds. Mean + SEM; Tg: n = 14-16; ntg: n = 8-9; T-test; *p<0.05.

 

Ultrasound Vocalization (USV)

The ability of rodents to communicate via ultrasound is investigated under different conditions. Possible alterations in the USV repertoire are assessed in rodent pups at early ages (P4–P13). Moreover, automated USV recordings can be performed in the same animal during adulthood and/ or while confronted with different conflict situations like social interaction in the Three Chamber social test or Reeperbahn test.