An Integrated μLED Optrode for Optogenetic Stimulation and Electrical Recording

Abstract

In this letter, we developed an integrated neural probe prototype for optogenetic stimulation by microscale light-emitting diode (μLED) and simultaneous recording of neural activities with microelectrodes on a single-polyimide platform. Optogenetics stimulates in vivo neural circuits with high-cellular specificity achieved by genetic targeting and precise temporal resolution by interaction of light-gated ion channels with optical beam. In our newly developed optrode probe, during optogenetic stimulation of neurons, continuous sensing of neuronal activities in vicinity of the activation site can provide feedback to stimulation or examine local responses in signal pathways. In the device, focusing the light from the μLED was achieved with an integrated photo-polymerized lens. The efficacy of the optrode for cortical stimulation and recording was tested on mice visual cortex neurons expressing channelrhodopsin-2. Stimulation intensity and frequency-dependent spiking activities of visual cortex were recorded. Our device has shown advantages over fiber-coupled laser-based optrode in terms of closed-loop integration, single-implant compactness and lower electrical power requirements, which would be clinically applicable for future prosthetic applications in personalized medicine.

Optical delivery of multiple opsin-encoding genes leads to targeted expression and white-light activation

“…Furthermore, the expression of chloride-channel opsin (halorhodopsin, NpHR 6 ) in longer-persisting cone photoreceptors has shown promise for vision restoration 6 . The optogenetic activation method is very promising because it requires only a low intensity of light, which can be delivered by a light-emitting diode or laser [7][8][9][10] . In addition, optogenetic approaches offer several advantages over electrical stimulation, such as cellular specificity, high temporal and spatial resolution, and minimal invasiveness [7][8][11][12][13][14] .…”

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

“…An example of a need for this type of functionality in neuroscience is in optogenetics, where localized delivery of light into the depth of the brain allows cell type selective control of cellular signalling and neural systems [9,10]. Strategies exploiting passive penetrating electrodes or optical fibres with interconnections to externally located electronics control/acquisition systems or light sources are valuable but suffer from challenges associated with tissue lesioning during insertion, persistent irritation that follows, and extreme engineering difficulties in thermal management [3,11,12]. Recently, Kim et al [13] developed injectable, wireless devices that incorporate arrays of microscale, inorganic light-emitting diodes (µ-ILEDs) with lateral dimensions 100 × 100 µm 2 and thicknesses of 6.45 µm (approx.…”

Hybrid intracerebral probe with integrated bare LED chips for optogenetic studies

“…On the one hand, the use of the Si stiffener ensures an improved probe rigidity for implantation in cerebral tissue, while on the other hand, it renders the probe surface relatively smooth despite the fact that LEDs protrude by 50 µm from the surface of the PI substrate. This is expected to minimize tissue response in comparison with devices with more rugged topography (Cao et al 2013). The implementation of commercial bare LEDs rather than custommade devices leads to a pronounced decrease in development time and fabrication cost compared to more advanced approaches using thin-film LED technologies (Ayub et al 2016;Goßler et al 2014;Scharf et al 2016;Wu et al 2015).…”