Neuronal Network Topology Indicates Distinct Recovery Processes after Stroke.

Despite substantial recent progress in network neuroscience, the impact of stroke on the distinct features of reorganizing neuronal networks during recovery has not been defined. Using a functional connections-based approach through 2-photon in vivo calcium imaging at the level of single neurons, we demonstrate for the first time the functional connectivity maps during motion and nonmotion states, connection length distribution in functional connectome maps and a pattern of high clustering in motor and premotor cortical networks that is disturbed in stroke and reconstitutes partially in recovery. Stroke disrupts the network topology of connected inhibitory and excitatory neurons with distinct patterns in these 2 cell types and in different cortical areas. These data indicate that premotor cortex displays a distinguished neuron-specific recovery profile after stroke.

Characterization of the geometry of negative dielectrophoresis traps for particle immobilization in digital microfluidic platforms.

This paper studies the effect of dielectrophoresis on particle manipulation and immobilization in digital microfluidic (DMF) devices. The dimensions of negative dielectrophoresis (nDEP) traps in the form of circular and square shapes are characterized using numerical and experimental approaches. These efforts will result in defining lifting and trapping zones, the ratio of which is shown to remain constant for trap sizes larger than 40 µm. As a result, a limiting constant K based on the ratio of the particle diameter to the trap size is introduced to identify the status of particle trapping prior to running numerical models or experiments. The results show that K must be less than 0.63 for trapping the particles on the nDEP traps. This study will also result in optimizing the trap size for single particle immobilization which is important for cell printing and growth applications.