A novel telemetric system to measure polysomnography biopotentials in freely moving animals

• Published in: Journal of neuroscience methods 2013-04, Vol.216 (2), p.79-86
• Main Authors: Zielinski, Mark R., Gerashchenko, Ludmila, Karpova, Svetlana A., Gerashchenko, Dmitry
• Format: Article
• Language: English
• ISSN: 0165-0270; 1872-678X
• DOI: 10.1016/j.jneumeth.2013.03.022

Mice are by far the most widely used species for scientific research including many studies involving biopotentials such as electroencephalogram (EEG) and electromyogram (EMG) signals for sleep analysis. Unfortunately, current methods for the analysis of these systems involve either tethered systems that are restrictive and heavy on the animal or wireless systems using transponders that are large relative to the animal and surgically invasive for implantation; thus natural behavior/activity is altered. Herein, we propose an inexpensive novel system for measuring electroencephalographic signals and other biopotentials in mice that allows for natural movement and evaluate it for the analysis of sleep architecture and EEG power during spontaneous sleep and sleep responses after sleep deprivation in mice. Vigilance states of non-rapid eye movement sleep (NREMS), rapid eye movement sleep (REMS), and wakefulness and EEG power and NREMS EEG delta power in the 0.5–4 Hz range (an indicator of sleep intensity) showed the typical diurnal rhythms found in mice using our new system and these values were similar to mice values using telemetry transponders. Mice that used the new system also demonstrated typical enhanced NREMS EEG delta power responses after sleep deprivation and few signal artifacts. Moreover, similar movement activity counts were found in the new system compared to a wireless system. This novel system for biopotential measuring can be used for polysomnography, infusion, microdialysate, and optogenetic studies providing a platform allowing reduced artifacts and a more natural moving environment for more accurate investigation of biological systems and pharmaceutical development.