In this study, a 60-channel microelectrode array(MEA) was fabricated and used to monitor the neural spikes and local field potentials(LFPs) of neurons differentiated from rat neural stem cells in vitro. The neurons we...In this study, a 60-channel microelectrode array(MEA) was fabricated and used to monitor the neural spikes and local field potentials(LFPs) of neurons differentiated from rat neural stem cells in vitro. The neurons were grown on the MEA surface to detect neural signals. Glutamate(Glu) was used to modulate neural activity during experiments. To enhance detection performance, platinum nanoparticles were modified onto the microelectrode site surface. Glutamate stimulated neural spikes and LFPs were recorded using the MEA. The average spike amplitude was approximately 70 μV in the normal state. The spike amplitude increased by 29% from 70 μV to 90 μV with Glu modulation. The firing rate increased by 69% from 4.01 Hz to 6.8 Hz with Glu modulation. The LFP power increased from 326 μW in the normal state to 617 μW with Glu modulation in the 0–10 Hz frequency band. Data analysis shows that neural activity stimulated by Glu modulation was recorded experimentally at high temporal-spatial resolution. These results may provide a new neuron detection method, as well as further understanding of neural stem cell spike firing and associated mechanisms.展开更多
Grid cells with stable hexagonal firing patterns in the medial entorhinal cortex(MEC)carry the vital function of serving as a metric for the surrounding environment.Whether this mechanism processes only spatial inform...Grid cells with stable hexagonal firing patterns in the medial entorhinal cortex(MEC)carry the vital function of serving as a metric for the surrounding environment.Whether this mechanism processes only spatial information or involves nonspatial information remains elusive.Here,we fabricated an MEC-shaped microelectrode array(MEA)to detect the variation in neural spikes and local field potentials of the MEC when rats forage in a square enclosure with a planar,three-dimensional object and social landmarks in sequence.The results showed that grid cells exhibited rate remapping under social conditions in which spike firing fields closer to the social landmark had a higher firing rate.Furthermore,global remapping showed that hexagonal firing patterns were rotated and scaled when the planar landmark was replaced with object and social landmarks.In addition,when grid cells were activated,the local field potentials were dominated by the theta band(5–8 Hz),and spike phase locking was observed at troughs of theta oscillations.Our results suggest the pattern separation mechanism of grid cells in which the spatial firing structure and firing rate respond to spatial and social information,respectively,which may provide new insights into how the brain creates a cognitive map.展开更多
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 ...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.展开更多
基金supported by the NSFC (No. 61960206012, No. 61527815, No. 61775216, No. 61975206, No. 61971400, No.61973292)the National Key R&D Program of nano science and technology of China (2017YFA0205902)the Key Research Programs of Frontier Sciences, CAS (QYZDJ-SSW-SYS015, XDA16020902)。
文摘In this study, a 60-channel microelectrode array(MEA) was fabricated and used to monitor the neural spikes and local field potentials(LFPs) of neurons differentiated from rat neural stem cells in vitro. The neurons were grown on the MEA surface to detect neural signals. Glutamate(Glu) was used to modulate neural activity during experiments. To enhance detection performance, platinum nanoparticles were modified onto the microelectrode site surface. Glutamate stimulated neural spikes and LFPs were recorded using the MEA. The average spike amplitude was approximately 70 μV in the normal state. The spike amplitude increased by 29% from 70 μV to 90 μV with Glu modulation. The firing rate increased by 69% from 4.01 Hz to 6.8 Hz with Glu modulation. The LFP power increased from 326 μW in the normal state to 617 μW with Glu modulation in the 0–10 Hz frequency band. Data analysis shows that neural activity stimulated by Glu modulation was recorded experimentally at high temporal-spatial resolution. These results may provide a new neuron detection method, as well as further understanding of neural stem cell spike firing and associated mechanisms.
基金sponsored by the National Key R&D Program(Grant No.2017YFA0205902)the National Natural Science Foundation of China(Grant No.62121003,61960206012,61973292,61975206,61971400,and 62171434)+1 种基金the Scientific Instrument Developing Project of the Chinese Academy of Sciences(Grant No.GJJSTD20210004)the Major Program of Scientific and Technical Innovation 2030(No.2021ZD0201603).
文摘Grid cells with stable hexagonal firing patterns in the medial entorhinal cortex(MEC)carry the vital function of serving as a metric for the surrounding environment.Whether this mechanism processes only spatial information or involves nonspatial information remains elusive.Here,we fabricated an MEC-shaped microelectrode array(MEA)to detect the variation in neural spikes and local field potentials of the MEC when rats forage in a square enclosure with a planar,three-dimensional object and social landmarks in sequence.The results showed that grid cells exhibited rate remapping under social conditions in which spike firing fields closer to the social landmark had a higher firing rate.Furthermore,global remapping showed that hexagonal firing patterns were rotated and scaled when the planar landmark was replaced with object and social landmarks.In addition,when grid cells were activated,the local field potentials were dominated by the theta band(5–8 Hz),and spike phase locking was observed at troughs of theta oscillations.Our results suggest the pattern separation mechanism of grid cells in which the spatial firing structure and firing rate respond to spatial and social information,respectively,which may provide new insights into how the brain creates a cognitive map.
基金sponsored by the Frontier Interdisciplinary Project of the Chinese Academy of Sciences (No.XK2022XXC003)National Natural Science Foundation of China (No.L2224042,61960206012,62121003,T2293731,62171434,61975206,61971400 and 61973292)+2 种基金the National Key Research and Development Program of China (No.2022YFC2402501,2022YFB3205602)Major Program of Scientific and Technical Innovation 2030 (No.2021ZD02016030)the Scientific Instrument Developing Project of the Chinese Academy of Sciences (No.GJJSTD20210004).
文摘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.
