In-situ monitoring of neurochemicals is of vital importance for the understanding of brain functions.Microelectrode-based photoelectrochemical(PEC) sensing has emerged as a promising tool for in vivo analysis since it...In-situ monitoring of neurochemicals is of vital importance for the understanding of brain functions.Microelectrode-based photoelectrochemical(PEC) sensing has emerged as a promising tool for in vivo analysis since it inherits the merits of both optical and electrochemical methods. However, the in-situ excitation of photoactive materials on the photoelectrode in living body is still a challenge because of limited tissue penetration depth of light. To circumvent this problem, we herein developed an implantable optical fiber(OF)-based microelectrode for in vivo PEC analysis. The working electrode was constructed by coating Au film as conducting layer and CdS@ZnO as photoactive material on a micron-sized OF,which was free of the limitation of light penetration in biological tissues. Further decoration of an antibiofouling layer on the surface made the sensor robust in biosamples. It was successfully applied for monitoring Cu^(2+) level in three different brain regions in the rat model of cerebral ischemia/reperfusion.展开更多
The subthalamic nucleus(STN)is considered the best target for deep brain stimulation treatments of Parkinson’s disease(PD).It is difficult to localize the STN due to its small size and deep location.Multichannel micr...The subthalamic nucleus(STN)is considered the best target for deep brain stimulation treatments of Parkinson’s disease(PD).It is difficult to localize the STN due to its small size and deep location.Multichannel microelectrode arrays(MEAs)can rapidly and precisely locate the STN,which is important for precise stimulation.In this paper,16-channel MEAs modified with multiwalled carbon nanotube/poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate)(MWCNT/PEDOT:PSS)nanocomposites were designed and fabricated,and the accurate and rapid identification of the STN in PD rats was performed using detection sites distributed at different brain depths.These results showed that nuclei in 6-hydroxydopamine hydrobromide(6-OHDA)-lesioned brains discharged more intensely than those in unlesioned brains.In addition,the MEA simultaneously acquired neural signals from both the STN and the upper or lower boundary nuclei of the STN.Moreover,higher values of spike firing rate,spike amplitude,local field potential(LFP)power,and beta oscillations were detected in the STN of the 6-OHDA-lesioned brain,and may therefore be biomarkers of STN localization.Compared with the STNs of unlesioned brains,the power spectral density of spikes and LFPs synchronously decreased in the delta band and increased in the beta band of 6-OHDA-lesioned brains.This may be a cause of sleep and motor disorders associated with PD.Overall,this work describes a new cellular-level localization and detection method and provides a tool for future studies of deep brain nuclei.展开更多
Artificial facial nerve prostheses are thought to restore eye-closed function in peripheral facial paralysis patients.At present,however,there is no adequate quantitative or qualitative information regarding myoelectr...Artificial facial nerve prostheses are thought to restore eye-closed function in peripheral facial paralysis patients.At present,however,there is no adequate quantitative or qualitative information regarding myoelectric signal（MES）features for healthy orbiculads oculi muscle（OOM）.The present study analyzed MES features of normal OOM in rabbits during the natural continuous eye-opening（N1）state,natural continuous eye-closing（N2）state,natural blink（N3）state,and evoked eye-closing（E）state according to time domain and frequency domain analysis.Results showed that OOM electrical activities in N1 and N2 states,as well as myoelectric amplitude,were low and stable.Nevertheless,during N3 and E states,OOM electrical activities were significantly increased and amplitude was much higher in the E state than in the N3 state.In the time domain,differences in MES peak absolute potential were not significant between N1 and N2 states,in the frequency domain,differences in power spectral density peak frequency of electromyogram signals were significant between two sets of four OOM movement states.These results suggest that OOM significantly contracts and induces eyelid-closing action.In addition,OOM is diastolic during the N1state.A N2 state does not require continuous intensive OOM contraction.Moreover,distinctions of quantitative information in time and frequency domain features of MES can be used as an OOM reference to identify muscle movement patterns.展开更多
Anesthesia plays a crucial role in regulating physiological states during medical procedures,but its effects on neural activity remain incompletely understood,particularly at the prefrontal cortical level.The prefront...Anesthesia plays a crucial role in regulating physiological states during medical procedures,but its effects on neural activity remain incompletely understood,particularly at the prefrontal cortical level.The prefrontal cortex is essential for various cognitive and motor functions,yet high-spatiotemporal-resolution electrodes at the cellular level remain challenging to develop,which has hindered the acquisition of detailed electrophysiological data from anesthetized subjects.Here,we design a 16-channel silicon-based microelectrode array(MEA),which,after modification with platinum black nanoparticles,exhibits significantly reduced impedance(22.5 kΩ)and increased phase(−33.5°),enhancing its electrical performance and electrophysiological signal detection capabilities.Using this modified MEA,we have recorded cellular-level neural activity during the recovery process of a rhesus macaque following prolonged anesthesia.Over a 660 s period,we observed a gradual increase in the neuronal firing rate in the F7 area,along with distinctive patterns in local field potentials across different frequency bands.Notably,power in the δ and θ bands increased continuously during recovery,highlighting their potential role in the transition from anesthesia to wakefulness.Our findings provide new insights into the dynamic recovery process of cortical neurons and offer a powerful tool for high-spatiotemporal-resolution neural monitoring in nonhuman primates.展开更多
L-glutamate,the most common excitatory neurotransmitter in the mammalian central nervous system(CNS),is associated with a wide range of neurological diseases.Because neurons in CNS communicate with each other both ele...L-glutamate,the most common excitatory neurotransmitter in the mammalian central nervous system(CNS),is associated with a wide range of neurological diseases.Because neurons in CNS communicate with each other both electrically and chemically,dualmode(electric and chemical)analytical techniques with high spatiotemporal resolution are required to better understand glutamate function in vivo.In the present study,a silicon-based implantable microelectrode array(MEA)composed of both platinum electrochemical and electrophysiological microelectrodes was fabricated using micro-electromechanical system.In the MEA probe,the electrophysiological electrodes have a low impedance of 0.018 MΩat 1 kHz,and the electrochemical electrodes show a sensitivity of 56 pAμM^(−1) to glutamate and have a detection limit of 0.5μM.The MEA probe was used to monitor extracellular glutamate levels,spikes and local field potentials(LFPs)in the striatum of anaesthetised rats.To explore the potential of the MEA probe,the rats were administered to KCl via intraperitoneal injection.K+significantly increases extracellular glutamate levels,LFP low-beta range(12–18 Hz)power and spike firing rates with a similar temporal profile,indicating that the MEA probe is capable of detecting dual-mode neuronal signals.It was concluded that the MEA probe can help reveal mechanisms of neural physiology and pathology in vivo.展开更多
基金financially supported by the National Natural Science Foundation of China(Nos.21625503 and 21906047)Natural Science Fund for Creative Research Groups of Hubei Province of China(No.2020CFA035)。
文摘In-situ monitoring of neurochemicals is of vital importance for the understanding of brain functions.Microelectrode-based photoelectrochemical(PEC) sensing has emerged as a promising tool for in vivo analysis since it inherits the merits of both optical and electrochemical methods. However, the in-situ excitation of photoactive materials on the photoelectrode in living body is still a challenge because of limited tissue penetration depth of light. To circumvent this problem, we herein developed an implantable optical fiber(OF)-based microelectrode for in vivo PEC analysis. The working electrode was constructed by coating Au film as conducting layer and CdS@ZnO as photoactive material on a micron-sized OF,which was free of the limitation of light penetration in biological tissues. Further decoration of an antibiofouling layer on the surface made the sensor robust in biosamples. It was successfully applied for monitoring Cu^(2+) level in three different brain regions in the rat model of cerebral ischemia/reperfusion.
基金funded by the National Natural Science Foundation of China(Nos.L2224042,T2293731,62121003,61960206012,61973292,62171434,61975206,and 61971400)the Frontier Interdisciplinary Project of the Chinese Academy of Sciences(No.XK2022XXC003)+2 种基金the National Key Research and Development Program of China(Nos.2022YFC2402501 and 2022YFB3205602)the Major Program of Scientific and Technical Innovation 2030(No.2021ZD02016030)the Scientific Instrument Developing Project of he Chinese Academy of Sciences(No.GJJSTD20210004).
文摘The subthalamic nucleus(STN)is considered the best target for deep brain stimulation treatments of Parkinson’s disease(PD).It is difficult to localize the STN due to its small size and deep location.Multichannel microelectrode arrays(MEAs)can rapidly and precisely locate the STN,which is important for precise stimulation.In this paper,16-channel MEAs modified with multiwalled carbon nanotube/poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate)(MWCNT/PEDOT:PSS)nanocomposites were designed and fabricated,and the accurate and rapid identification of the STN in PD rats was performed using detection sites distributed at different brain depths.These results showed that nuclei in 6-hydroxydopamine hydrobromide(6-OHDA)-lesioned brains discharged more intensely than those in unlesioned brains.In addition,the MEA simultaneously acquired neural signals from both the STN and the upper or lower boundary nuclei of the STN.Moreover,higher values of spike firing rate,spike amplitude,local field potential(LFP)power,and beta oscillations were detected in the STN of the 6-OHDA-lesioned brain,and may therefore be biomarkers of STN localization.Compared with the STNs of unlesioned brains,the power spectral density of spikes and LFPs synchronously decreased in the delta band and increased in the beta band of 6-OHDA-lesioned brains.This may be a cause of sleep and motor disorders associated with PD.Overall,this work describes a new cellular-level localization and detection method and provides a tool for future studies of deep brain nuclei.
基金the National Natural Science Foundation of China,No.60876082,81070779the grant from Shanghai Committee of Science and Technology,No.0852nm06600the "Shu Guang" Project supported by Shanghai Municipal Educa-tion Commission and Shanghai Education Devel-opment Foundation,No.08SG13
文摘Artificial facial nerve prostheses are thought to restore eye-closed function in peripheral facial paralysis patients.At present,however,there is no adequate quantitative or qualitative information regarding myoelectric signal（MES）features for healthy orbiculads oculi muscle（OOM）.The present study analyzed MES features of normal OOM in rabbits during the natural continuous eye-opening（N1）state,natural continuous eye-closing（N2）state,natural blink（N3）state,and evoked eye-closing（E）state according to time domain and frequency domain analysis.Results showed that OOM electrical activities in N1 and N2 states,as well as myoelectric amplitude,were low and stable.Nevertheless,during N3 and E states,OOM electrical activities were significantly increased and amplitude was much higher in the E state than in the N3 state.In the time domain,differences in MES peak absolute potential were not significant between N1 and N2 states,in the frequency domain,differences in power spectral density peak frequency of electromyogram signals were significant between two sets of four OOM movement states.These results suggest that OOM significantly contracts and induces eyelid-closing action.In addition,OOM is diastolic during the N1state.A N2 state does not require continuous intensive OOM contraction.Moreover,distinctions of quantitative information in time and frequency domain features of MES can be used as an OOM reference to identify muscle movement patterns.
基金sponsored by the National Key R&D Program of China(Grant Nos.2022YFC2402500 and 2022YFB3205602)the National Natural Science Foundation of China(Grant Nos.62121003,T2293730,T2293731,62333020,62171434,62471291)+2 种基金the Major Program of Scientific and Technical Innovation 2030(Grant No.2021ZD02016030)the Joint Foundation Program of the Chinese Academy of Sciences(Grant No.8091A170201)the Scientific Instrument Developing Project of the Chinese Academy of Sciences(Grant No.PTYQ2024BJ0009).
文摘Anesthesia plays a crucial role in regulating physiological states during medical procedures,but its effects on neural activity remain incompletely understood,particularly at the prefrontal cortical level.The prefrontal cortex is essential for various cognitive and motor functions,yet high-spatiotemporal-resolution electrodes at the cellular level remain challenging to develop,which has hindered the acquisition of detailed electrophysiological data from anesthetized subjects.Here,we design a 16-channel silicon-based microelectrode array(MEA),which,after modification with platinum black nanoparticles,exhibits significantly reduced impedance(22.5 kΩ)and increased phase(−33.5°),enhancing its electrical performance and electrophysiological signal detection capabilities.Using this modified MEA,we have recorded cellular-level neural activity during the recovery process of a rhesus macaque following prolonged anesthesia.Over a 660 s period,we observed a gradual increase in the neuronal firing rate in the F7 area,along with distinctive patterns in local field potentials across different frequency bands.Notably,power in the δ and θ bands increased continuously during recovery,highlighting their potential role in the transition from anesthesia to wakefulness.Our findings provide new insights into the dynamic recovery process of cortical neurons and offer a powerful tool for high-spatiotemporal-resolution neural monitoring in nonhuman primates.
基金This work was sponsored by the Major National Scientific Research Plan(Grant Nos.2011CB933202 and 2014CB744605)the NSFC(Grant Nos.61125105 and 61471342)+1 种基金the Beijing Science and Technology Plan(Grant Nos.Z141100000214002 and Z141102003414014)the Key Programs of the Chinese Academy of Sciences(Grant No.KJZD-EW-L11-2).
文摘L-glutamate,the most common excitatory neurotransmitter in the mammalian central nervous system(CNS),is associated with a wide range of neurological diseases.Because neurons in CNS communicate with each other both electrically and chemically,dualmode(electric and chemical)analytical techniques with high spatiotemporal resolution are required to better understand glutamate function in vivo.In the present study,a silicon-based implantable microelectrode array(MEA)composed of both platinum electrochemical and electrophysiological microelectrodes was fabricated using micro-electromechanical system.In the MEA probe,the electrophysiological electrodes have a low impedance of 0.018 MΩat 1 kHz,and the electrochemical electrodes show a sensitivity of 56 pAμM^(−1) to glutamate and have a detection limit of 0.5μM.The MEA probe was used to monitor extracellular glutamate levels,spikes and local field potentials(LFPs)in the striatum of anaesthetised rats.To explore the potential of the MEA probe,the rats were administered to KCl via intraperitoneal injection.K+significantly increases extracellular glutamate levels,LFP low-beta range(12–18 Hz)power and spike firing rates with a similar temporal profile,indicating that the MEA probe is capable of detecting dual-mode neuronal signals.It was concluded that the MEA probe can help reveal mechanisms of neural physiology and pathology in vivo.
