Measuring Behavior 2005: Tanner et al.

Caffeine and Modafinil: Differentiation of changes in locomotor activity assessed by telemetry, video scoring and tracking.

R. Tanner, S. Loomis, A. Kulla and G. Gilmour

Eli Lilly and Company Ltd, Lilly Research Centre, Erl Wood Manor, Sunninghill Road, Windlesham, Surrey, UK

Of all stimulants, Caffeine has unarguably the most widespread use. However, its effects on cardiovascular parameters and its potential for tolerance have fuelled the development of other wake-promoting agents. One of these compounds is Modafinil. A differentiating finding between both drugs in rodents is that, despite their reliable and dose-dependent induction of wakefulness, Modafinil, in contrast to Caffeine and other stimulants, was reported to be devoid of prominent effects on the intensity of locomotor activity. In the present study the wake-promotion of Caffeine and Modafinil is quantified in Lister Hooded rats chronically instrumented for telemetric sleep EEG recordings. In addition to sleep and wake scores, activity, body temperature and heart rate were assessed in the same experiment. Activity measurements from the telemetry systems have been compared to visual analysis of behavior derived from digital video recordings and compared to activity scores from Caffeine- and Modafinil-treated animals based on video tracking (using EthoVision^® 2.2 Noldus Information Technology bv, The Netherlands) in activity cages. The analysis of activity assessed by essentially three different systems highlights important aspects of the interpretation of locomotor data. All experiments were performed under the UK Animals (Scientific Procedures) Act 1986.

Paper presented at Measuring Behavior 2005 , 5^th International Conference on Methods and Techniques in Behavioral Research, 30 August - 2 September 2005, Wageningen, The Netherlands.