Deep brain implantable microelectrode arrays for detection and functional localization of the subthalamic nucleus in rats with Parkinson’s disease

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.

Impaired Spatial Firing Representations of Neurons in the Medial Entorhinal Cortex of the Epileptic Rat Using Microelectrode Arrays

Epilepsy severely impairs the cognitive behavior of patients.It remains unclear whether epilepsy-induced cognitive impairment is associated with neuronal activities in the medial entorhinal cortex(MEC),a region known for its involvement in spatial cognition.To explore this neural mechanism,we recorded the spikes and local field potentials from MEC neurons in lithium-pilocarpine-induced epileptic rats using self-designed microelectrode arrays.Through the open field test,we identified spatial cells exhibiting spatially selective firing properties and assessed their spatial representations in relation to the progression of epilepsy.Meanwhile,we analyzed theta oscillations and theta modulation in both excitatory and inhibitory neurons.Furthermore,we used a novel object recognition test to evaluate changes in spatial cognitive ability of epileptic rats.After the epilepsy modeling,the spatial tuning of various types of spatial cells had suffered a rapid and pronounced damage during the latent period(1 to 5 d).Subsequently,the firing characteristics and theta oscillations were impaired.In the chronic period(>10 d),the performance in the novel object experiment deteriorated.In conclusion,our study demonstrates the detrimental effect on spatial representations and electrophysiological properties of MEC neurons in the epileptic latency,suggesting the potential use of these changes as a"functional biomarker"for predicting cognitive impairment caused by epilepsy.

Nanomaterial-based microelectrode arrays for in vitro bidirectional brain–computer interfaces:a review

A bidirectional in vitro brain–computer interface(BCI)directly connects isolated brain cells with the surrounding environment,reads neural signals and inputs modulatory instructions.As a noninvasive BCI,it has clear advantages in understanding and exploiting advanced brain function due to the simplified structure and high controllability of ex vivo neural networks.However,the core of ex vivo BCIs,microelectrode arrays(MEAs),urgently need improvements in the strength of signal detection,precision of neural modulation and biocompatibility.Notably,nanomaterial-based MEAs cater to all the requirements by converging the multilevel neural signals and simultaneously applying stimuli at an excellent spatiotemporal resolution,as well as supporting long-term cultivation of neurons.This is enabled by the advantageous electrochemical characteristics of nanomaterials,such as their active atomic reactivity and outstanding charge conduction efficiency,improving the performance of MEAs.Here,we review the fabrication of nanomaterial-based MEAs applied to bidirectional in vitro BCIs from an interdisciplinary perspective.We also consider the decoding and coding of neural activity through the interface and highlight the various usages of MEAs coupled with the dissociated neural cultures to benefit future developments of BCIs.

Detection of neuronal defensive discharge information transmission and characteristics in periaqueductal gray double-subregions using PtNP/PEDOT:PSS modified microelectrode arrays

Threatened animals respond with appropriate defensive behaviors to survive.It has been accepted that midbrain periaqueductal gray(PAG)plays an essential role in the circuitry system and organizes defensive behavioral responses.However,the role and correlation of different PAG subregions in the expression of different defensive behaviors remain largely unexplored.Here,we designed and manufactured a microelectrode array(MEA)to simultaneously detect the activities of dPAG and vPAG neurons in freely behaving rats.To improve the detection performance of the MEAs,PtNP/PEDOT:PSS nanocomposites were modified onto the MEAs.Subsequently,the predator odor was used to induce the rat’s innate fear,and the changes and information transmission in neuronal activities were detected in the dPAG and vPAG.Our results showed that the dPAG and vPAG participated in innate fear,but the activation degree was distinct in different defense behaviors.During flight,neuronal responses were stronger and earlier in the dPAG than the vPAG,while vPAG neurons responded more strongly during freezing.By applying high-performance MEA,it was revealed that neural information spread from the activated dPAG to the weakly activated vPAG.Our research also revealed that dPAG and vPAG neurons exhibited different defensive discharge characteristics,and dPAG neurons participated in the regulation of defense responses with burst-firing patterns.The slow activation and continuous firing of vPAG neurons cooresponded with the regulation of long-term freezing responses.The results demonstrated the important role of PAG neuronal activities in controlling different aspects of defensive behaviors and provided novel insights for investigating defense from the electrophysiological perspective.

Recent advances and research progress on microsystems and bioeffects of terahertz neuromodulation

Terahertz waves can interact with the nervous system of organisms under certain conditions.Compared to common optical modulation methods,terahertz waves have the advantages of low photon energy and low risk;therefore,the use of terahertz waves to regulate the nervous system is a promising new method of neuromodulation.However,most of the research has focused on the use of terahertz technology for biodetection,while relatively little research has been carried out on the biological effects of terahertz radiation on the nervous system,and there are almost no review papers on this topic.In the present article,we begin by reviewing principles and objects of research regarding the biological effects of terahertz radiation and summarizing the current state of related research from a variety of aspects,including the bioeffects of terahertz radiation on neurons in vivo and in vitro,novel regulation and detection methods with terahertz radiation devices and neural microelectrode arrays,and theoretical simulations of neural information encoding and decoding.In addition,we discuss the main problems and their possible causes and give some recommendations on possible future breakthroughs.This paper will provide insight and assistance to researchers in the fields of neuroscience,terahertz technology and biomedicine.

Progress and Focus of Journal of Remote Sensing in 2021-2022

Introduction of JRS.Remote sensing technology,which emerged in the 1960s,is an increasingly used support for understanding Earth’s past,present,and future and opened a new chapter for humankind to explore Earth[1].

基于L_(1/2)正则化理论的稀疏雷达成像

稀疏雷达成像旨在远低于奈奎斯特率采样下对稀疏场景实施高分辨率微波成像.本文概述作者在解决这一问题上的系统探索与创新实践.核心贡献包括:提出L_(1/2)正则化理论作为新的稀疏雷达成像理论,提出不直接基于雷达观测而基于雷达回波模拟算子重构的稀疏雷达成像新模型,提出以3D相变图分析为依据的稀疏雷达成像系统设计方法等.根据新的理论、模型和设计方法,研制了首部稀疏雷达原理样机并开展了机载实验.实验验证了所提新理论、新模型与新方法的正确性和可行性,展示广阔应用前景.

The First Engineering Journal from Nature Publishing Group:Microsystems & Nanoengineering

After extensive collaboration and detailed planning,the Nature Publishing Group(NPG)and the Institute of Electronics,Chinese Academy of Sciences(IECAS)are very proud to launch the co-published academic journal,Microsystems&Nanoengineering,onMay 28,2015.We consider it as a great honor to write this editorial for the birth of this journal.

Journal of Remote Sensing: A Platform to Promote International High-Quality Research and Innovation

Remote sensing(RS)is a fast-growing emerging interdisciplinary field focused on observing our planet and living environment.The number of publications in this field increases dramatically from about 921 documents in 1999 to 8,242 documents in 2019 according to the records in the Science Citation Index Expanded(SCI-EXPANDED)database.While there are many journals publishing new developments in RS,the space is still limited to cover the thousands of exciting articles each year to document the advancement in both RS science and technology.This journal,supported by the Science Partner Journal program,with editorial board members composed of internationally renowned scientists,is aimed at providing a new space to publish high-quality,online-only papers on RS theory,science,techniques,and applications that are related to the Earth systems.More importantly,unlike many RS journals where financial profit is also one of the main goals,this journal is solely focused on the communication and distribution of knowledge in RS.Articles are free to publish through June 2023 and will always be free to read for everyone.Authors are also strongly encouraged to deposit the data that supports their research in a trusted repository that supports the FAIR principles.We will strive hard to best serve the RS community.

One-year anniversary:The progress of Microsystems & Nanoengineering

With time passing imperceptibly,Microsystems&Nanoengineering has indeed attracted the attention of its international peers in MEMS and nanotechnology since it was launched as a new journal on May 28,2015.Microsystems&Nanoengineering is the first engineering journal co-published by the Nature Publishing Group(NPG)and the Institute of Electronics of Chinese Academy of Sciences(IECAS).On behalf of the editorial board of Microsystems&Nanoengineering,we would like to express our deep gratitude to our readers,authors,and reviewers.We sincerely thank all of you for your strong and consistent support!