Evolution of optogenetic microdevices

Abstract

Abstract. Implementation of optogenetic techniques is a recent addition to the neuroscientists' preclinical research arsenal, helping to expose the intricate connectivity of the brain and allowing for on-demand direct modulation of specific neural pathways. Developing an optogenetic system requires thorough investigation of the optogenetic technique and of previously fabricated devices, which this review accommodates. Many experiments utilize bench-top systems that are bulky, expensive, and necessitate tethering to the animal. However, these bench-top systems can make use of power-demanding technologies, such as concurrent electrical recording. Newer portable microdevices and implantable systems carried by freely moving animals are being fabricated that take advantage of wireless energy harvesting to power a system and allow for natural movements that are vital for behavioral testing and analysis. An investigation of the evolution of tethered, portable, and implantable optogenetic microdevices is presented, and an analysis of benefits and detriments of each system, including optical power output, device dimensions, electrode width, and weight is given. Opsins, light sources, and optical fiber coupling are also discussed to optimize device parameters and maximize efficiency from the light source to the fiber, respectively. These attributes are important considerations when designing and developing improved optogenetic microdevices.

Optical Control of Cardiac Function with a Photoswitchable Muscarinic Agonist

“…Unlike optogenetics, photopharmacology rely on the use of exogenous light-regulated small molecules that can photocontrol native targets and that could be tested and approved using standard drug development procedures. [8][9][10][11][12][13][14][15] These molecules can be used in combination with devices that deliver light to specific locations in the body 7,[16][17][18] in order to remotely control drug dosing and duration of action. Since the activity of drugs is structure-dependent, reversible photoresponsive drugs are obtained by the rational introduction of a molecular photoswitch into the structure of a bioactive compound.…”

Tools for Controlling Activity of Neural Circuits Can Boost Gastrointestinal Research

“…Although for routine application of optogenetic it is still necessary tethering the experimental subject to lasers or LED light sources, ongoing lines of research also focus on the implementation of portable and implantable micro devices that can be carried by animals during enacted behavior (Kim et al, 2013 ; Montgomery et al, 2015 ; Park et al, 2015 ). While implementation and easy-access to such devices will be a major advance for the neuroscience field as a whole (for review see Kale et al, 2015 ), implantable and wireless devices will be crucial for a full incorporation of optogenetics into the gastrointestinal research.…”

Nanoparticle-Based and Bioengineered Probes and Sensors to Detect Physiological and Pathological Biomarkers in Neural Cells

“…To enhance these approaches, it might be attractive to adapt them for use in exciting new implantable wireless fluidic devices that have been developed for programmable in vivo pharmacology (Jeong et al, 2015 ), thereby providing an interesting alternative to established optogenetics techniques (Warden et al, 2014 ). Optogenetic approaches and their attractions and limitations have been extensively reviewed elsewhere (Williams and Deisseroth, 2013 ; Thompson et al, 2014 ; Fan and Li, 2015 ; Kale et al, 2015 ; Lüscher et al, 2015 ; Tonegawa et al, 2015 ; Webber et al, 2015 ).…”