Optogenetic Brain Interfaces

Abstract

Abstract-The brain is a large network of interconnected neurons where each cell functions as a nonlinear processing element. Unraveling the mysteries of information processing in the complex networks of the brain requires versatile neurostimulation and imaging techniques. Optogenetics is a new stimulation method which allows the activity of neurons to be modulated by light. For this purpose, the cell-types of interest are genetically targeted to produce light-sensitive proteins. Once these proteins are expressed, neural activity can be controlled by exposing the cells to light of appropriate wavelengths. Optogenetics provides a unique combination of features, including multi-modal control over neural function and genetic targeting of specific celltypes. Together, these versatile features combine to a powerful experimental approach, suitable for the study of the circuitry of psychiatric and neurological disorders.The advent of optogenetics was followed by extensive research aimed to produce new lines of light-sensitive proteins and to develop new technologies: for example, to control the distribution of light inside the brain tissue or to combine optogenetics with other modalities including electrophysiology, electrocorticography, nonlinear microscopy, and functional magnetic resonance imaging.In this paper, the authors review some of the recent advances in the field of optogenetics and related technologies and provide their vision for the future of the field.

Polymer Fiber Probes Enable Optical Control of Spinal Cord and Muscle Function In Vivo

“…With the introduction of optogenetics [8,9] , a method that permits on-demand excitation and inhibition of activity in optically-sensitized neurons with light pulses, integration of photonic modules into microelectronic neural recording probes yielded closed-loop sensor-actuator devices [10] . These probes often combined optical fibers with established neural recording technologies such as silicon miltielectrode arrays [11,12] , multitrodes [13,14] and tetrodes [15] .…”

Patterned Optogenetic Modulation of Neurovascular and Metabolic Signals

“…Optogenetics involves the insertion of light-sensitive opsins into the cell membrane to infer optical excitation or inhibition in neural cells. 1,2 The most commonly used techniques involve the use of optically driven cationic channels (e.g., channelrhodopsin-2 (ChR2)) to excite activity and ionic pumps (e.g., halorhodopsin and archaerhodopsin) to inhibit neural activity. As a genetic technique, promotors can be used to express opsins in specific cell types.…”

Angularly Resolved Deep Brain Fluorescence Imaging Using a Single Optical Fiber

“…It is important to consider the position of an optical fiber as well as the direction of light delivery during optogenetic stimulation [19,20] or other neuroscience experiments. The measured data clearly showed that the expression of fluorescence protein can diffuse in different directions with respect to the fibers main lobe of radiation.…”