Preparatory cortical and spinal settings to counteract anticipated and non-anticipated perturbations

Publication date: 4 December 2017 Source:Neuroscience, Volume 365 Author(s): Michael Wälchli, Craig D. Tokuno, Jan Ruffieux, Martin Keller, Wolfgang Taube Little is known about how the central nervous system prepares postural responses differently in anticipated compared to non-anticipated perturbations. To investigate this, participants were exposed to translational and rotational perturbations presented in a blocked (anticipated) and a random (non-anticipated) design. The preparatory setting (‘central set’) was measured by H-reflexes, motor-evoked potentials (MEPs), and short-interval intracortical inhibition (SICI) shortly before perturbation onset in the soleus of 15 healthy adults. Additionally, the behavioral consequences of differential preparatory settings were analyzed by comparing the short- (SLR), medium- (MLR), and long-latency response (LLR) of the soleus after anticipated and non-anticipated rotations and translations. H-reflexes elicited before perturbation were different between conditions (p =0.023) with larger amplitudes in anticipated translations compared to anticipated rotations (37.0%; p =0.048). Reduced SICI was found in the three conditions containing perturbations compared to static standing (p <0.001). Muscular responses assessed after perturbations remained unchanged for the SLR and MLR, whereas the LLR was decreased in anticipated rotations (−36.2%; p =0.002) and increased in anticipated translations (16.7%; p =0.046) compared ...
Source: Neuroscience - Category: Neuroscience Source Type: research