Nanowire transistor arrays for mapping neural circuits in acute brain slices

Abstract

Revealing the functional connectivity in natural neuronal networks is central to understanding circuits in the brain. Here, we show that silicon nanowire field-effect transistor (Si NWFET) arrays fabricated on transparent substrates can be reliably interfaced to acute brain slices. NWFET arrays were readily designed to record across a wide range of length scales, while the transparent device chips enabled imaging of individual cell bodies and identification of areas of healthy neurons at both upper and lower tissue surfaces. Simultaneous NWFET and patch clamp studies enabled unambiguous identification of action potential signals, with additional features detected at earlier times by the nanodevices. NWFET recording at different positions in the absence and presence of synaptic and ion-channel blockers enabled assignment of these features to presynaptic firing and postsynaptic depolarization from regions either close to somata or abundant in dendritic projections. In all cases, the NWFET signal amplitudes were from 0.3-3 mV. In contrast to conventional multielectrode array measurements, the small active surface of the NWFET devices, ∼0.06 μm 2 , provides highly localized multiplexed measurements of neuronal activities with demonstrated sub-millisecond temporal resolution and, significantly, better than 30 μm spatial resolution. In addition, multiplexed mapping with 2D NWFET arrays revealed spatially heterogeneous functional connectivity in the olfactory cortex with a resolution surpassing substantially previous electrical recording techniques. Our demonstration of simultaneous high temporal and spatial resolution recording, as well as mapping of functional connectivity, suggest that NWFETs can become a powerful platform for studying neural circuits in the brain.

Recent advances in large-scale assembly of semiconducting inorganic nanowires and nanofibers for electronics, sensors and photovoltaics

“…Furthermore, high-density arrays of nanowire FETs can be used to map signals with high spatial resolution at the subcellular level. [190][191][192][193][194] These advances may have broad applications in fundamental biophysical studies of cellular function, drug assays and prosthetic devices.…”

“…[181][182][183][184][185][186][187][188][189][190][191][192][193][194][195][196][197] The principle of biological detection based on nanowire FETs is very simple. For example, when a single virus particle binds to an antibody receptor linked to the surface of a nanowire FET detector, it yields a conductance change due to the change in nanowire surface charge; when the virus particle subsequently unbinds, the conductance returns to the baseline.…”

Thermal analysis of injectable, cellular-scale optoelectronics with pulsed power

“…Stretchable electronics opened new avenues for electronic circuits, light-emitting diodes (LEDs), sensors and other components with the ability to bend, twist and stretch, for wrapping the external surfaces of soft tissues (e.g. brain, skin and heart) [1][2][3][4][5][6][7][8]. A shortcoming of such device architectures is that they do not provide the ability to insert electronic/optoelectronic systems into precise locations of biological tissues.…”

Assembly and integration of semiconductor nanowires for functional nanosystems

“…More generally, interfacing multiple NW inputs and outputs to neurons and neural networks enables the stimulation, inhibition, or reversibly blocking of signal propagation along specific pathways while simultaneously mapping signal flow throughout the network. This approach could not only be used to investigate synaptic processing in neural networks and to explore hybrid circuits for information processing [77], but be useful for developing flexible realtime cellular assays, for example, for drug discovery and testing. …”