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Single-Cell Photothermal Neuromodulation for Functional Mapping of Neural Networks
摘要： Photothermal neuromodulation is one of the emerging technologies being developed for neuroscience studies because it can provide minimal-invasive control of neural activity in the deep brain with sub-millimeter precision. However, single cell modulation without genetic modification still remains a challenge, hindering its path to the broad application. Here, we introduce a nanoplasmonic approach to inhibit single neural activity with high temporal resolution. Low intensity of near infrared (NIR) was focused at single cell size on gold nanorod (GNR) integrated microelectrode array platform, generating photothermal effect underneath a target neuron for photothermal stimulation. We found that the photothermal stimulation modulates the spontaneous activity of a target neuron in an inhibitory manner. Single neuron inhibition was fast and highly reliable without thermal damage, and it can induce changes in network firing patterns, potentially suggesting their application for in vivo circuit modulation and functional connectomes.
关键词： photothermal effects,local surface plasmonic resonance,neuromodulation,gold nanorod,neuron
更新于2025-09-23 15:23:52
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A wireless closed-loop system for optogenetic peripheral neuromodulation
摘要： The fast-growing field of bioelectronic medicine aims to develop engineered systems that can relieve clinical conditions by stimulating the peripheral nervous system. This type of technology relies largely on electrical stimulation to provide neuromodulation of organ function or pain. One example is sacral nerve stimulation to treat overactive bladder, urinary incontinence and interstitial cystitis (also known as bladder pain syndrome). Conventional, continuous stimulation protocols, however, can cause discomfort and pain, particularly when treating symptoms that can be intermittent (for example, sudden urinary urgency). Direct physical coupling of electrodes to the nerve can lead to injury and inflammation. Furthermore, typical therapeutic stimulators target large nerve bundles that innervate multiple structures, resulting in a lack of organ specificity. Here we introduce a miniaturized bio-optoelectronic implant that avoids these limitations by using (1) an optical stimulation interface that exploits microscale inorganic light-emitting diodes to activate opsins; (2) a soft, high-precision biophysical sensor system that allows continuous measurements of organ function; and (3) a control module and data analytics approach that enables coordinated, closed-loop operation of the system to eliminate pathological behaviours as they occur in real-time. In the example reported here, a soft strain gauge yields real-time information on bladder function in a rat model. Data algorithms identify pathological behaviour, and automated, closed-loop optogenetic neuromodulation of bladder sensory afferents normalizes bladder function. This all-optical scheme for neuromodulation offers chronic stability and the potential to stimulate specific cell types.
关键词： optogenetics,closed-loop system,bladder function,wireless implant,bioelectronic medicine,neuromodulation
更新于2025-09-23 15:23:52
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Intracortical neural stimulation with untethered, ultrasmall carbon fiber electrodes mediated by the photoelectric effect
摘要： Objective: Neural stimulation with tethered, electrically activated probes is damaging to neural tissue and lacks good spatial selectivity and stable chronic performance. The photoelectric effect, which converts incident light into electric potential and heat, provides an opportunity for a tetherless stimulation method. We propose a novel stimulation paradigm that relies on the photoelectric effect to stimulate neurons around a free-floating, ultrasmall (7-8μm diameter) carbon fiber probe. Methods: A 2-photon microscope induced photo-stimulation with a laser. Chronoamperometry and chronopotentiometry were used to characterize the electrochemical properties of photo-stimulation, while the fluorescence of Rhodamine-B was used to quantify temperature changes. Results: Photo-stimulation caused a local cathodic potential pulse with minimal leakage current. Stimulation induced voltage deflections of 0.05 - 0.4V in vitro, varying linearly with the power of the laser source (5 – 40 mW). Temperature increases in the immediate vicinity of the electrode were limited to 2.5°C, suggesting that this stimulation modality can be used without inducing heat damage. Successful stimulation was supported in vivo by increased calcium fluorescence in local neurons at stimulation onset in a transgenic GCaMP-3 mouse model. Furthermore, cells activated by photo-stimulation were closer to the electrode than in electrical stimulation under similar conditions, indicating increased spatial precision. Conclusion: Our results support the hypothesis that the proposed photoelectric method is effective for neural stimulation. Significance: Photoelectric stimulation is precise and avoids the need for a potentially destructive tether, making it a promising alternative to electrical stimulation.
关键词： GCaMP,electrochemistry,neuromodulation,photovoltaic effect,2-photon microscopy,temperature-dependent,fluorescence
更新于2025-09-23 15:23:52
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[IEEE 2018 Photonics in Switching and Computing (PSC) - Limassol, Cyprus (2018.9.19-2018.9.21)] 2018 Photonics in Switching and Computing (PSC) - WDM PON Receivers Enhanced by Integrated SOAs
摘要： Transcranial stimulation of the brain can be achieved by pulses of magnetic field delivered by a large electric coil. However, application of such pulses by rapidly moving small permanent magnets could offer several advantages in terms of ease of use, safety, multifocality, and portability. We have, therefore, developed a wearable brain stimulator consisting of small neodymium magnets that are spun at high speed by electric motors mounted on a cap. Here, we describe the operation of the stimulator and present initial evidence that its stimulation of the cerebral cortex produces physiological effects. We first physically tested the electromagnetic induction pattern produced by our stimulator compared with conventional transcranial magnetic stimulation. We then recorded the effects of stimulation of the primary motor cortical representation of the intrinsic muscles of the thumb including abductor pollicis brevis (APB). We studied these effects on spontaneously occurring electromyographic fasciculation potentials or spontaneous motor unit potentials (sMUPs) known to occur in healthy adult human subjects in resting APB, and compared them with the effects of sham stimulation. We found that while a single stimulus cannot elicit a motor-evoked potential, repetitive stimulation delivered by our stimulator modulates sMUP activity. This transcranial rotating permanent magnet stimulation could, therefore, produce neuromodulation at a single or multiple closely spaced cortical sites.
关键词： Brain stimulation,neuromodulation,medical treatment
更新于2025-09-23 15:19:57
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Optogenetic modulation of cortical neurons using Organic Light Emitting Diodes (OLEDs)
摘要： Approach - Cultured mouse cortical neurons were transfected with light-sensitive opsins such as blue-light sensitive channel-rhodopsin (ChR2) and green-light sensitive chimeric channel-rhodopsin (C1V1tt) and stimulated using blue and green OLEDs (with 455 and 520 nm peak emission spectra respectively) at a power of 1 mW/mm2 under pulsed conditions. vivo in a transgenic mouse model. Significance - The above results indicate the feasibility of generating sufficient luminance from OLEDs to perform neuromodulation both in vitro and in vivo. This opens up the possibility of developing thin, flexible OLED films with multiple stimulation sites that can conform to the shape of the neuronal targets in the brain or the peripheral nervous system. However, stability of these OLEDs under chronic conditions still needs to be carefully assessed with appropriate packaging approaches. Main results - We demonstrate neuromodulation and optostimulus-locked, single unit-neuronal activity in neurons expressing stimulating opsins (34 units on n=4 MEAs, each with 16 recordable channels). We also validated the optostimulus-locked response in preliminary experiments in a channel-rhodopsin expressing transgenic mouse model, where at least three isolatable single neuronal cortical units respond to OLED stimulation.
关键词： C1V1tt,Neuromodulation,Channel-rhodopsin,OLEDs,Optogenetics
更新于2025-09-19 17:13:59
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[IEEE 2019 IEEE Eurasia Conference on IOT, Communication and Engineering (ECICE) - Yunlin, Taiwan (2019.10.3-2019.10.6)] 2019 IEEE Eurasia Conference on IOT, Communication and Engineering (ECICE) - Mobile Phone Audio Combined with Self-Made Laser Light Transmission Frequency Wireless Actuated Electromagnetic Lock
摘要： Caloric vestibular stimulation (CVS) to elicit the vestibulo-ocular reflex has long been used in clinical settings to aid in the diagnosis of balance disorders and to confirm the absence of brainstem function. While a number of studies have hinted at the potential therapeutic applications of CVS, the limitations of existing devices have frustrated that potential. Current CVS irrigators use water or air during short-duration applications; however, this approach is not tenable for longer duration therapeutic protocols or home use. Here, we describe a solid-state CVS device we developed in order to address these limitations. This device delivers tightly controlled time-varying thermal waveforms, which can be programmed through an external control unit. It contains several safety features, which limit patients to the prescribed waveform and prevent the potential for temperature extremes. In this paper, we provide evidence that CVS treatment with time-varying, but not constant temperature waveforms, elicits changes in cerebral blood flow physiology consistent with the neuromodulation of brainstem centers, and we present results from a small pilot study, which demonstrate that the CVS can safely and feasibly be used longitudinally in the home setting to treat episodic migraine. Together, these results indicate that this solid-state CVS device may be a viable tool for non-invasive neuromodulation.
关键词： Caloric vestibular stimulation,brainstem,migraine,cerebral blood flow,neuromodulation
更新于2025-09-19 17:13:59