As gene expression studies
considerably benefit from better knowledge about where in the nervous system the relevant phenotypic differentiations are most likely to occur (Shaw and Danley 2003), our results will also contribute to research efforts to obtain a genic understanding of speciation in crickets (Ellison et al. 2011) and also other acoustically communicating insects such as Drosophila (Rideout et al. 2007; von Philipsborn et al. 2011). Conflict of Interest The authors declare that there is no conflict of interest. Role of authors: All authors had full access to all the data in the study and take responsibility for the integrity Inhibitors,research,lifescience,medical of the data and the accuracy of the data analysis. Study concept and design: B. H., S. S. Acquisition of data: S. S. Analysis and interpretation of data: S. S., B. H. Drafting of the manuscript: S. S., B. H. Administrative, technical, and material support: B. H., Inhibitors,research,lifescience,medical S. S. Obtained funding: B. H.
A multitude of human movements is characterized by different muscles that act together at one joint. Synergists are defined as muscles which actively provide an additive contribution to a particular function during a contraction (Basmajian and Luca 1985). The contributions of muscle activities that act across a joint depend on the Inhibitors,research,lifescience,medical direction of contraction and the force (Buchanan et al. 1986; Ashe 1997). Each synergy comprised the coordinated
activations of specific muscle groups that included synchronized bursts of electromyografic (EMG) activity for some muscles and asynchronous increases and decreases in EMG activity for other muscles (Enoka 2008). A large number of studies investigated the recruitment patterns Inhibitors,research,lifescience,medical of synergistic muscles in different muscle groups. These Inhibitors,research,lifescience,medical recruitment patterns are both controlled by the descending drives from supraspinal centers
(Ashe 1997) and by the neural circuitry in the spinal cord (Tresch et al. 1999). A common approach to study control strategies of synergistic muscle activity is to impair one muscle of a muscle group (Sacco et al. 1997; Akima et al. of 2002; Kinugasa et al. 2005; de Ruiter et al. 2008). Neuromuscular electrical stimulation (NMES) is an appropriate tool to decrease the activity of one muscle locally (Adams et al. 1993; Vanderthommen et al. 2000). NMES is defined as SN 38 series of intermittent stimuli to superficial skeletal muscles, with the main objective to trigger visible muscle contractions due to the activation of the intramuscular nerve branches (Maffiuletti 2010). Akima et al. (2002) examined the muscle activity in the muscle heads of the m. quadriceps femoris at 50% of maximal voluntary contraction (MVC). Between the trials, the m. vastus lateralis was fatigued using NMES for 30 min. It was observed that the muscle activity of the unfatigued muscles was increased compared with the baseline. Thereby, the intended movement task could still be accomplished.