The use of animal models has been a major factor in the advancement of scientific and medical knowledge in virtually every biomedical field. Recent advances in genetics have provided the potential for even better models, particularly in gene-altered mice and rats. To fully exploit the potential of these models, the animals need to be evaluated on physiology as well as behavior and genotype. Unfortunately, the size of some rodents makes it difficult to use some established methods of recording physiological signals that involve invasive procedures and the implantation of electrodes. In addition, while these techniques have yielded valuable information regarding mechanisms, there are a number of limitations with applying them to behavioral questions. These include potential stress on the animal from surgery or restraint and the possibility that the recording technique can affect the parameter being measured, or the animals behavior. Current techniques that require surgery also may involve considerable labor in preparing and caring for chronically implanted animals. These limitations indicate the need for non-invasive techniques that can record physiological parameters. Our goal is to develop methodologies for non-invasive, non-contact monitoring of physiology and behavior in rodent animal models, and to assess their utility in determining arousal state (wakefulness and sleep). To accomplish these goals we will develop sensor applications and software for the non-invasive collection of heart rate, respiratory rate, body surface temperature and activity in rodents. We will assess pulse Doppler radar and/or ultrasonic sensors for acquiring heart rate, respiratory rate and activity, and we will develop infrared thermal imaging applications for acquiring body temperature. We will then validate non-invasively collected data for heart rate, respiratory rate, temperature and activity with data concurrently collected with established techniques. We will compare the data obtained with the sensor applications we develop with that obtained with established methodologies (e.g., telemetrically recorded heart rate, whole body plethysmography and diaphragm recordings for respiratory rate, telemetrically recorded temperature, and photobeam measurement of activity). Finally, we will determine if these signals can be used to reliably determine three arousal states (wakefulness, NREM and REM) by comparing state discrimination with non- invasively obtained signals to EEG based scoring of arousal states. This project has significance for public health because it can provide improved techniques for studies using animal models. The proposed applications have particular significance for studies of behavior and sleep. ? ? ?
| Zeng, Tao; Mott, Christopher; Mollicone, Daniel et al. (2012) Automated determination of wakefulness and sleep in rats based on non-invasively acquired measures of movement and respiratory activity. J Neurosci Methods 204:276-87 |
