Appendix 252: How do they siphon neurons? (w/ 9 Related Scientific Abstracts, Sabrina Wallace, Feb. 14, 2024)

A) Optogenetics:

“The most dramatic applications of fluorescent sensor pro­teins come from the GCaMP family of Ca2þ indicators (Fig. 2 B).

The concentration of this ion blips upward every time a neuron fires.

Expression of GCaMP-based reporters in the brains of worms, flies, fish, and mice has led to spec­tacular movies of the coordinated activation patterns of thousands of neurons.

Within the last year, scientists have started to engineer more complex combinations of functions into GFP-based optogenetic tools.

For instance, the calcium-modulated pho­toactivatable ratiometric integrator (CaMPARI) protein starts life as a fluorescent calcium indicator, and, in the simultaneous presence of neural activity and violet illumi­nation, converts from green to red (9).

This behavior lets one record a photochemical imprint of the calcium level in a large volume of tissue at a defined moment in time. One can then image the tissue at leisure, with high resolu­tion in space, to map this snapshot of activity.”

https://cohenweb.rc.fas.harvard.edu/Publications/Cohen_Optogenetics_Review_BPJ_2016.pdf

B) Recent progress in human body energy harvesting for smart bioelectronic system

a b s t r a c t

From every heartbeat to every footstep, human beings dissipate energy all the time. Researchers are trying to harvest energy from the human body and convert it into electricity, which can be supplied to electronic medical devices closely related to human health.

Such an energy recycling form is currently a research hotspot in the fields of energy harvesting and bioelectronics. This review firstly summarizes the distribution and characteristics of three primary energy sources contained in the human body, including thermal energy, chemical energy, and mechanical energy.

Afterwards, the applicable energy harvesting technologies and corresponding working
mechanisms for different energy sources are introduced. Some typical demos and practical applications of each type of human body energy harvesting technology are also presented. Specifically, the advantages and critical issues of different energy harvesting technologies are summarized, and corresponding promising solutions are also provided. Besides, the interaction strategies between various energy harvesting devices and the human body are summarized from the aspects of wearable and implantable applications.

Finally, the concept of a self-powered closed-loop bioelectronic system (SCBS) is put forward for the first time, which organically combines portable electronic devices, implantable electronic medical devices, energy harvesting devices, and the human body. The prospect of symbiosis between the SCBS and the human body is provided. The demands and future development trends of the SCBS are also discussed.

https://sci-hub.se/downloads/2021-05-31/35/zou2021.pdf?download=true

Originally article find by Vanilla Bean.

C) “Scientists at CU Boulder have tapped into a poltergeist-like property of electrons to design devices that can capture excess heat from their environment—and turn it into usable electricity.
The researchers have described their new “optical rectennas” in a paper published today in the journal Nature Communications. These devices, which are too small to see with the naked eye, are roughly 100 times more efficient than similar tools used for energy harvesting. And they achieve that feat through a mysterious process called “resonant tunneling”—in which electrons pass through solid matter without spending any energy. “

“Rectennas (short for “rectifying antennas”), she explained, work a bit like car radio antennas. But instead of picking up radio waves and turning them into tunes, optical rectennas absorb light and heat and convert it into power.”
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“Moddel is looking forward to the day when rectennas sit on top of everything from solar panels on the ground to lighter-than-air vehicles in the air: “If you can capture heat radiating into deep space, then you can get power anytime, anywhere.”

https://www.colorado.edu/today/2021/05/18/optical-rectennas

D) Optogenetic control of mitochondrial metabolism and Ca2+ signaling by mitochondria-targeted opsins

Key mitochondrial functions such as ATP production, Ca+ uptake and release, and substrate accumulation depend on the proton electrochemical gradient (ΔμH+) across the inner membrane.

Al­though several drugs can modulate ΔμH+ , their effects are hardly reversible, and lack cellular specificity and spatial resolution. Al­though channelrhodopsins are widely used to modulate the plasma membrane potential of excitable cells, mitochondria have thus far eluded optogenetic control.

Here we describe a toolkit of optometabolic constructs based on selective targeting of channelr­hodopsins with distinct functional properties to the inner mito­chondrial membrane of intact cells.

We show that our strategy enables a light-dependent control of the mitochondrial membrane potential (Δψm) and coupled mitochondrial functions such as ATP synthesis by oxidative phosphorylation, Ca+ dynamics, and respi­ratory metabolism.

By directly modulating Δψm, the mitochondria­targeted opsins were used to control complex physiological processes such as spontaneous beats in cardiac myocytes and glucose-dependent ATP increase in pancreatic β-cells. Furthermore, our optometabolic tools allow modulation of mitochondrial functions in single cells and defined cell regions.

https://www.pnas.org/doi/pdf/10.1073/pnas.1703623114

E) (Method to pump cells full of Ca+ for optogenetic neuron mapping)

by The American Society for Biochemistry and Molecular Biology, Inc.

Stimulation of Capacitative Calcium Entry in HL-60 Cells by Nanosecond Pulsed Electric Fields

“Nanosecond pulsed electric fields (nsPEFs) are hypothesized to affect intracellular structures in living cells providing a new means to modulate cell signal transduction mechanisms.

The effects of nsPEFs on the release of internal calcium and activation of calcium influx in HL-60 cells were investigated by using real time fluorescent microscopy with Fluo-3 and fluorometry with Fura-2. nsPEFs induced an increase in intracellular calcium levels that was seen in all cells.

With pulses of 60 ns duration and electric fields between 4 and 15 kV/cm, intracellular calcium increased 200–700 nM, respectively, above basal levels ( 100 nM), while the uptake of propidium iodide was absent.

This suggests that increases in intracellular calcium were not because of plasma membrane electroporation. nsPEF and the purinergic agonist UTP induced calcium mobilization in the presence and absence of extracellular calcium with similar kinetics and appeared to target the same inositol 1,4,5-trisphosphate- and thapsigargin-sensitive calcium pools in the endoplasmic reticulum.

For cells exposed to either nsPEF or UTP in the absence of extracellular calcium, there was an electric field-dependent or UTP dose-dependent increase in capacitative calcium entry when calcium was added to the extracellular media. These findings suggest that nsPEFs, like ligand-mediated responses, release calcium from similar internal calcium pools and thus activate plasma membrane cal- cium influx channels or capacitative calcium entry.”

https://www.jbc.org/action/showPdf?pii=S0021-9258%2820%2966658-3

F) Genetically targeted magnetic control of the nervous system

Optogenetic and chemogenetic actuators are critical for deconstructing the neural correlates of behavior. However, these tools have several limitations, including invasive modes of stimulation or slow on/off kinetics. We have overcome these disadvantages by synthesizing a single-component, magnetically sensitive actuator, “Magneto,” comprising the cation channel TRPV4 fused to the paramagnetic protein ferritin. We validated noninvasive magnetic control over neuronal activity by
demonstrating remote stimulation of cells using in vitro calcium imaging assays, electrophysiological recordings in brain slices, in vivo electrophysiological recordings in the brains of freely moving mice, and behavioral outputs in zebrafish and mice.

As proof of concept, we used Magneto to delineate a causal role of striatal dopamine receptor 1 neurons in mediating reward behavior in mice. Together our results present Magneto as an actuator capable of remotely controlling circuits associated with complex animal behaviors.

https://rifters.com/real/articles/Genetically-targeted-magnetic-control-of-the-nervous-system.pdf

G) Piezoelectric Nanoparticle-Assisted Wireless Neuronal Stimulation

ABSTRACT

Tetragonal barium titanate nanoparticles (BTNPs) have been exploited as nanotransducers owing to their piezoelectric properties, in order to provide indirect electrical stimulation to SH-SY5Y neuron-like cells.

Following application of ultrasounds to cells treated with BTNPs, fluorescence imaging of
ion dynamics revealed that the synergic stimulation is able to elicit a significant cellular response in terms of calcium and sodium fluxes; moreover, tests with appropriate blockers demonstrated that voltage-gated membrane channels are
activated.

The hypothesis of piezoelectric stimulation of neuron-like cells was supported by lack of cellular response in the presence of cubic nonpiezoelectric
BTNPs, and further corroborated by a simple electroelastic model of a BTNP subjected to ultrasounds, according to which the generated voltage is compatible with the values required for the activation of voltage-sensitive channels.

https://pubs.acs.org/doi/pdf/10.1021/acsnano.5b03162?download=true

H) mmWave/5G RFID Systems for Long-Range Wireless Sensing and Remote Localization Applications

Introduction
In recent years, the tremendous growth in the demand for consumer electronics combined with the advances in the area of millimeter-waves (mmWave) has enabled great improvement in the field of Internet of Things (IoT), which is consequently paving the way for our societies to make the idea of Smart Cities possible. Some applications that lie under the ‘Smart Cities’ scope include structural health monitoring, ubiquitous biochemical and health monitoring, positioning and localization applications, as well as low-cost energy harvesting devices. In addition, the realm of virtual reality (VR) has also drawn tremendous attention among regular consumers, increasing the need for improving our current technologies related to digital twins in order to map physical objects into the digital world.
In this regard, Radio Frequency Identification (RFID) based technologies represent an adequate solution to satisfy the needs brought by the advances in IoT applications, as they allow to wirelessly read multiple sensor nodes in a highly- efficient manner. Particularly with backscatter RFID, a user is capable of communicating with a sensor tag using minimal amounts of power, as the tag uses the signal sent by the reader to operate and communicate back. In addition, RFID technology allows one to construct a network of multiple sensor tags than can be continuously monitored for a wide range of applications. And as 5G capabilities become more available, it is possible design miniaturized RFID tags that operate at mmWave frequencies. In this paper, we briefly summarize some of the most
recent advances in wireless sensing and remote localization applications that operate at mmWave frequencies.

https://eps.ieee.org/images/files/Rf_THz__TC_article_mm_Wave_5G_RFID_Systems_for_Long-Range_Wireless_Sensing_and_Remote_Localization_Applications.pdf

I) Cardiac optogenetics: regulating brain states via the heart()

Cardiac optogenetics allows light-mediated excitation of the heart with high spatiotemporal resolution and in a cell-type- specific manner. Optogenetic stimulation of cardiomyocytes has been successfully achieved in vitro and in anesthetized mice,5 enabling precise cardiac pacing with light. However, mostly owing to the technical difficulties of light-delivery in a contracting organ, cardiac optogenetics had not yet been applied in freely moving animals, a prerequisite that needs to be met to study the causal influence of heart dynamics on brain function and behaviour.

Could heart rate be tuned in a specific manner to attenuate the pathological impact of psychiatric disorders such as anxiety or depression? By optogenetically stimulating cardiomyocytes Hsueh and colleagues could impose strong tachycardia, which caused enhanced anxiety-like behaviour. The opposite effect would be desirable to potentially treat emotional disorders associated with high sympathetic tone via downregulation of heart function and resulting interoception. In the long run, this could be achieved via specific optogenetic cardio-inhibitory approaches but in order to do so, we need a better understanding of how the heart conveys signals to the brain, and vice versa.

https://www.nature.com/articles/s41392-023-01582-6.pdf

Original PDF find by Vanilla Bean.

J) Generation of electrical power under human skin by subdermal solar cell arrays for implantable bioelectronic devices

2016
Korea

Photoelectric
Photovoltaic devices (IPV)
Energy harvesting strategies:
Wireless energy transmission
Electrochemical reaction
Mechanical motion

https://www.sciencedirect.com/science/article/abs/pii/S0956566316311320