Daily jaw muscle activity in freely moving rats measured with radio-telemetry

Kawai Nobuhiko

Tanaka Eiji

Langenbach Geerling E. J.

van Wessel Tim

Brugman Peter

Sano Ryota

van Eijden Theo M. G. J.

Tanne Kazuo

European Journal of Oral Sciences

The jaw muscle activity of rats has been investigated for specific tasks. However, the daily jaw muscle use remains unclear. The purpose of the present study was to examine daily jaw muscle activity and its variability over time in the rat (n=12) by the use of radio-telemetry. A telemetric device was implanted for the continuous recording of masseter and digastric muscle activity. Daily muscle use was characterized by calculation of the total time each muscle was active (duty time), the number of bursts, and the average length of bursts. All parameters were estimated for activities exceeding various levels (5-90%) of the day's peak activity. Daily muscle use remained constant for 4 wk. At the low activity level, the duty time and burst number of the digastric were higher than that of the masseter significantly (p<0.01), while the opposite was true at the high activity level (p<0.05). No significant intermuscular correlation was observed between the number of bursts of the masseter and digastric muscle but the inter-individual variation of both muscles changed depending on the level of activation. These findings suggested that the masseter and digastric muscle showed a differential active pattern depending on activity level.

EMG

telemetry

rat

masseter

digastric

Medical sciences [ 490 ]

eng

Blackwell Publishing

Copyright (c) 2007 Blackwell Publishing. The definitive version is available at www.blackwell-synergy.com

[ISSN] 0909-8836

[DOI] 10.1111/j.1600-0722.2007.00424.x

[NCID] AA11033550

[DOI] http://dx.doi.org/10.1111/j.1600-0722.2007.00424.x