Cortical Plasticity Induced by Short-Term Multimodal Musical Rhythm Training

Performing music is a multimodal experience involving the visual, auditory, and somatosensory modalities as well as the motor system. Therefore, musical training is an excellent model to study multimodal brain plasticity. Indeed, we have previously shown that short-term piano practice increase the magnetoencephalographic (MEG) response to melodic material in novice players. Here we investigate the impact of piano training using a rhythmic-focused exercise on responses to rhythmic musical material. Musical training with non musicians was conducted over a period of two weeks. One group (sensorimotor-auditory, SA) learned to play a piano sequence with a distinct musical rhythm, another group (auditory, A) listened to, and evaluated the rhythmic accuracy of the performances of the SA-group. Training-induced cortical plasticity was evaluated using MEG, comparing the mismatch negativity (MMN) in response to occasional rhythmic deviants in a repeating rhythm pattern before and after training. The SA-group showed a significantly greater enlargement of MMN and P2 to deviants after training compared to the A- group. The training-induced increase of the rhythm MMN was bilaterally expressed in contrast to our previous finding where the MMN for deviants in the pitch domain showed a larger right than left increase. The results indicate that when auditory experience is strictly controlled during training, involvement of the sensorimotor system and perhaps increased attentional recources that are needed in producing rhythms lead to more robust plastic changes in the auditory cortex compared to when rhythms are simply attended to in the auditory domain in the absence of motor production

In vivo longitudinal study of rodent skeletal muscle atrophy using ultrasonography

Muscle atrophy is a widespread ill condition occurring in many diseases, which can reduce quality of life and increase morbidity and mortality. We developed a new method using non-invasive ultrasonography to measure soleus and gastrocnemius lateralis muscle atrophy in the hindlimb-unloaded rat, a well-Accepted model of muscle disuse. Soleus and gastrocnemius volumes were calculated using the conventional truncated-cone method and a newly-designed sinusoidal method. For Soleus muscle, the ultrasonographic volume determined in vivo with either method was linearly correlated to the volume determined ex-vivo from excised muscles as muscle weight-To-density ratio. For both soleus and gastrocnemius muscles, a strong linear correlation was obtained between the ultrasonographic volume and the muscle fiber cross-sectional area determined ex-vivo on muscle cryosections. Thus ultrasonography allowed the longitudinal in vivo evaluation of muscle atrophy progression during hindlimb unloading. This study validates ultrasonography as a powerful method for the evaluation of rodent muscle atrophy in vivo, which would prove useful in disease models and therapeutic trials

Novel Al2O3–SiO2 aerogel/porous zirconia composite with ultra-low thermal conductivity

Highly porous zirconia fibers networks with a quasi-layered microstructure were successfully fabricated using vacuum squeeze moulding. The effects of inorganic binder content on the microstructure, room-temperature thermal and mechanical properties of fibrous porous zirconia ceramics were systematically investigated. Al2O3-SiO2 aerogel was impregnated into fibrous porous ceramics, and the microstructures, thermal and mechanical properties of Al2O3-SiO2 aerogel/porous zirconia composites were also studied. Results show that the Al2O3-SiO2 aerogel/porous zirconia composites exhibited higher compressive strength (i.e., 1.22 MPa in the z direction) and lower thermal conductivity [i.e., 0.049 W/(m/K)]. This method provides an efficient way to prepare high-temperature thermal insulation materials