Figure 6: Behavioural characterization of TN-XXL transgenic mice and wild-type controls (WT).

(a) Hole board test. Distance covered, distance in time, resting, jumping, rearing behaviour and the number of nose pokes were analysed during a 30-min monitoring period. (b) Rotarod. Mice were placed on accelerating drums. The time at which an animal fell from the drum was measured. The increased latency from day 1 (d1) to day 2 (d2) and day 3 (d3) indicates motor learning behaviour. (c) Elevated plus maze (EPM). Time spent in open arm (TOA), entries in open arm (EOA) and locomotion as motility control was analysed. (d) Social interaction test (SI). Pairs of unfamiliar mice (n=7 pairs each) were placed into a new environment. The time of active contacts (sniffing, licking, close following, grooming) was recorded. (e) Acoustic startle response (ASR). To test for hyperarousal, startle stimuli consisted of white noise bursts of 75, 90, 105 and 115 dB were applied. (f) Fear conditioning test. Mice were placed into a shock chamber and a tone was presented followed by an electric foot shock. After conditioning, mice were exposed either to the tone in neutral environment (d1) or to the shock chamber without applying an electric shock (d2). Freezing behaviour served as a measure of fear memory. (g) Tail-suspension test. Mice were suspended by the tail from a metal rod and the immobility times during the last 4 min of the 6 min trial period was recorded. Data in all graphs are shown as mean±s.e.m. (sample sizes were 12–15 animals for each test).