Wireless optoelectronic photometers for monitoring neuronal dynamics in the deep brain

Abstract

Capabilities for recording neural activity in behaving mammals have greatly expanded our understanding of brain function. Some of the most sophisticated approaches use light delivered by an implanted fiber-optic cable to optically excite genetically encoded calcium indicators and to record the resulting changes in fluorescence. Physical constraints induced by the cables and the bulk, size, and weight of the associated fixtures complicate studies on natural behaviors, including social interactions and movements in environments that include obstacles, housings, and other complex features. Here, we introduce a wireless, injectable fluorescence photometer that integrates a miniaturized light source and a photodetector on a flexible, needle-shaped polymer support, suitable for injection into the deep brain at sites of interest. The ultrathin geometry and compliant mechanics of these probes allow minimally invasive implantation and stable chronic operation. In vivo studies in freely moving animals demonstrate that this technology allows high-fidelity recording of calcium fluorescence in the deep brain, with measurement characteristics that match or exceed those associated with fiber photometry systems. The resulting capabilities in optical recordings of neuronal dynamics in untethered, freely moving animals have potential for widespread applications in neuroscience research.

High-density multi-fiber photometry for studying large-scale brain circuit dynamics

“…For example, high-density fiber arrays could expand the use of fiber optics in fMRI experiments [40][41][42] and thereby contribute to a better understanding of the relationship between neuronal, glial, and vascular dynamics. A combination with extracellular silicon probes 6 or emerging optoelectronic neural probes 43,44 may provide new possibilities for relating individual neuron activity to larger-scale population activity 45 , even up to the mesoscale 46 . Similarly, the combination with multi-site neurochemical recordings 47 would allow studies of how neuromodulator activity impacts brainwide neural network dynamics.…”

A wireless, implantable optoelectrochemical probe for optogenetic stimulation and dopamine detection

“…1d), which is ready for implantation into the deep tissue of animal brains. Compared with other possible device geometries like physically bonded fibers/wires 37,38 or laterally placed thin-film sensors 14,39,40 , the vertically stacked device structure is more advantageous because: 1)…”

“…Representative examples include our recently developed optoelectronic probes for wireless optogenetic stimulation and fluorescence recording in freely moving rodents [11][12][13][14][15] . Besides electrical pulses and calcium flows, neurotransmitters, which comprise a plethora of chemicals like dopamine, glutamate, serotonin, etc., are of critical importance and direct relevance in neural activities and brain functions 16,17 .…”

Investigation of Low‐Current Direct Stimulation for Rehabilitation Treatment Related to Muscle Function Loss Using Self‐Powered TENG System

“…Various implantable devices are developed for healthcare monitoring purpose, such as chemical sensors to detect glucose and lactate, [1,2] flexible electronics to record electrophysiological signals, [3] optoelectronic photometers to monitor neuronal dynamics, [4] and pressure sensors for blood flow monitoring [5] and orthopedic applications. Various implantable devices are developed for healthcare monitoring purpose, such as chemical sensors to detect glucose and lactate, [1,2] flexible electronics to record electrophysiological signals, [3] optoelectronic photometers to monitor neuronal dynamics, [4] and pressure sensors for blood flow monitoring [5] and orthopedic applications.…”