Movement-dependent electrical stimulation for volitional strengthening of cortical connections in behaving monkeys.

Correlated activity of neurons can lead to long-term strengthening or weakening of the connections between them. In addition, the behavioral context, imparted by execution of physical movements or the presence of a reward, can modulate the plasticity induced by Hebbian mechanisms. In the present study, we have combined behavior and induced neuronal correlations to strengthen connections in the motor cortex of adult behaving monkeys.

Erratum: Addendum: Miniaturized Technologies for Enhancement of Motor Plasticity.

[This corrects the article on p. 30 in vol. 4, PMID: 27148525.

Miniaturized Technologies for Enhancement of Motor Plasticity.

The idea that the damaged brain can functionally reorganize itself - so when one part fails, there lies the possibility for another to substitute - is an exciting discovery of the twentieth century. We now know that motor circuits once presumed to be hardwired are not, and motor-skill learning, exercise, and even mental rehearsal of motor tasks can turn genes on or off to shape brain architecture, function, and, consequently, behavior. This is a very significant alteration from our previously static view of the brain and has profound implications for the rescue of function after a motor injury.

Generating arbitrary chemical patterns for multipoint dosing of single cells.

Living cells reside within anisotropic microenvironments that orchestrate a broad range of polarized responses through physical and chemical cues. To unravel how localized chemical signals influence complex behaviors, tools must be developed for establishing patterns of chemical gradients that vary over subcellular dimensions. Here, we present a strategy for addressing this critical need in which an arbitrary number of chemically distinct, subcellular dosing streams are created in real time within a microfluidic environment.

Dynamic remodeling of subcellular chemical gradients using a multi-directional flow device.

Elucidation of the mechanisms by which external chemical cues regulate polarized cellular behaviors requires tools that can rapidly recast chemical landscapes with subcellular resolution. Here, we describe an approach for creating steep microscopic gradients of cellular effectors at any desired position in culture that can be reoriented rapidly to evaluate dynamic responses. In this approach, micrometre pores are ablated in a membrane that supports cell adherence, allowing dosing reagent from an underlying reservoir to enter the cell-culture flow chamber as sharp streams that are directed at subcellular targets by using a system of paired sources and drains to specify flow direction.

Microscale transport and sorting by kinesin molecular motors.

As biomolecular detection systems shrink in size, there is an increasing demand for systems that transport and position materials at micron- and nanoscale dimensions. Our goal is to combine cellular transport machinery-kinesin molecular motors and microtubules-with integrated optoelectronics into a hybrid biological/engineered microdevice that will bind, transport, and detect specific proteins, DNA/RNA molecules, viruses, or cells. For microscale transport, 1.