Objective quantification of tremor in conscious unrestrained rats, exemplified with 5-hydroxytryptamine-mediated...

To accomplish an objective quantification of tremor in conscious unrestrained rats, a registration device based on accelerometry was developed. Tremor intensity was continuously recorded by a small piezoresistive accelerometer (Egal 125-10D, Entran Devices) mounted on the back of the freely moving rat. The accelerometer was connected to a Grass Polygraph, where the analog signal was quantified as arbitrary marks/min by a 7P10 integrating unit. The integrated signals were then further analyzed by a desk-top computer (Luxor ABC-80). By analyzing tremor response to central serotonergic system activation, the reproductibility as well as the advantages and limitations of this recording system were demonstrated.