{"title":"Device for detection of activity-dependent changes in neural spheroids at MHz and GHz frequencies","authors":"","doi":"10.1016/j.bios.2024.116816","DOIUrl":null,"url":null,"abstract":"<div><div>Intracellular processes triggered by neural activity include changes in ionic concentrations, protein release, and synaptic vesicle cycling. These processes play significant roles in neurological disorders. The beneficial effects of brain stimulation may also be mediated through intracellular changes. There is a lack of label-free techniques for monitoring activity-dependent intracellular changes. Electromagnetic (EM) waves at frequencies larger than 1 × 10<sup>6</sup> Hz (1 MHz) were previously used to probe intracellular contents of cells, as cell membrane becomes “invisible” at this frequency range. EM waves interact with membranes of intracellular organelles, proteins, and water in the MHz – GHz range. In this work, we developed a device for probing the interaction between active neurons’ intracellular contents and EM waves. The device used an array of grounded coplanar waveguides (GCPWs) to deliver EM waves to a three-dimensional (3D) spheroid of rat cortical neurons. Neural activity was evoked using optogenetics, with synchronous detection of propagation of EM waves. Broadband measurements were conducted in the MHz-GHz range to track changes in transmission coefficients. Neuronal activity was found to reversibly alter EM wave transmission. Pharmacological suppression of neuronal activity abolished changes in transmission. Time constants of changes in transmission were in the seconds – tens of seconds range, suggesting the presence of relatively slow, activity-dependent intracellular processes. This study provides the first evidence that EM transmission through neuronal tissue is activity-dependent in MHz – GHz range. Device developed in this work may find future applications in studies of the mechanisms of neurological disorders and the development of new therapies.</div></div>","PeriodicalId":259,"journal":{"name":"Biosensors and Bioelectronics","volume":null,"pages":null},"PeriodicalIF":10.7000,"publicationDate":"2024-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Biosensors and Bioelectronics","FirstCategoryId":"1","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0956566324008236","RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"BIOPHYSICS","Score":null,"Total":0}
引用次数: 0
Abstract
Intracellular processes triggered by neural activity include changes in ionic concentrations, protein release, and synaptic vesicle cycling. These processes play significant roles in neurological disorders. The beneficial effects of brain stimulation may also be mediated through intracellular changes. There is a lack of label-free techniques for monitoring activity-dependent intracellular changes. Electromagnetic (EM) waves at frequencies larger than 1 × 106 Hz (1 MHz) were previously used to probe intracellular contents of cells, as cell membrane becomes “invisible” at this frequency range. EM waves interact with membranes of intracellular organelles, proteins, and water in the MHz – GHz range. In this work, we developed a device for probing the interaction between active neurons’ intracellular contents and EM waves. The device used an array of grounded coplanar waveguides (GCPWs) to deliver EM waves to a three-dimensional (3D) spheroid of rat cortical neurons. Neural activity was evoked using optogenetics, with synchronous detection of propagation of EM waves. Broadband measurements were conducted in the MHz-GHz range to track changes in transmission coefficients. Neuronal activity was found to reversibly alter EM wave transmission. Pharmacological suppression of neuronal activity abolished changes in transmission. Time constants of changes in transmission were in the seconds – tens of seconds range, suggesting the presence of relatively slow, activity-dependent intracellular processes. This study provides the first evidence that EM transmission through neuronal tissue is activity-dependent in MHz – GHz range. Device developed in this work may find future applications in studies of the mechanisms of neurological disorders and the development of new therapies.
期刊介绍:
Biosensors & Bioelectronics, along with its open access companion journal Biosensors & Bioelectronics: X, is the leading international publication in the field of biosensors and bioelectronics. It covers research, design, development, and application of biosensors, which are analytical devices incorporating biological materials with physicochemical transducers. These devices, including sensors, DNA chips, electronic noses, and lab-on-a-chip, produce digital signals proportional to specific analytes. Examples include immunosensors and enzyme-based biosensors, applied in various fields such as medicine, environmental monitoring, and food industry. The journal also focuses on molecular and supramolecular structures for enhancing device performance.