1.Effect of repeated transcranial magnetic stimulation on excitability of glutaminergic neurons and gamma-aminobutyric neurons in mouse hippocampus.
Jiale WANG ; Chong DING ; Rui FU ; Ze ZHANG ; Junqiao ZHAO ; Haijun ZHU
Journal of Biomedical Engineering 2025;42(1):73-81
Repeated transcranial magnetic stimulation (rTMS) is one of the commonly used brain stimulation techniques. In order to investigate the effects of rTMS on the excitability of different types of neurons, this study is conducted to investigate the effects of rTMS on the cognitive function of mice and the excitability of hippocampal glutaminergic neurons and gamma-aminobutyric neurons from the perspective of electrophysiology. In this study, mice were randomly divided into glutaminergic control group, glutaminergic magnetic stimulation group, gamma-aminobutyric acid energy control group, and gamma-aminobutyric acid magnetic stimulation group. The four groups of mice were injected with adeno-associated virus to label two types of neurons and were implanted optical fiber. The stimulation groups received 14 days of stimulation and the control groups received 14 days of pseudo-stimulation. The fluorescence intensity of calcium ions in mice was recorded by optical fiber system. Behavioral experiments were conducted to explore the changes of cognitive function in mice. The patch-clamp system was used to detect the changes of neuronal action potential characteristics. The results showed that rTMS significantly improved the cognitive function of mice, increased the amplitude of calcium fluorescence of glutamergic neurons and gamma-aminobutyric neurons in the hippocampus, and enhanced the action potential related indexes of glutamergic neurons and gamma-aminobutyric neurons. The results suggest that rTMS can improve the cognitive ability of mice by enhancing the excitability of hippocampal glutaminergic neurons and gamma-aminobutyric neurons.
Animals
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Mice
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Hippocampus/cytology*
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Transcranial Magnetic Stimulation
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Neurons/physiology*
;
Male
;
Cognition/physiology*
;
gamma-Aminobutyric Acid/metabolism*
;
Action Potentials/physiology*
2.A head direction cell model based on a spiking neural network with landmark-free calibration.
Naigong YU ; Jingsen HUANG ; Ke LIN ; Zhiwen ZHANG
Journal of Biomedical Engineering 2025;42(5):970-976
In animal navigation, head direction is encoded by head direction cells within the olfactory-hippocampal structures of the brain. Even in darkness or unfamiliar environments, animals can estimate their head direction by integrating self-motion cues, though this process accumulates errors over time and undermines navigational accuracy. Traditional strategies rely on visual input to correct head direction, but visual scenes combined with self-motion information offer only partially accurate estimates. This study proposed an innovative calibration mechanism that dynamically adjusts the association between visual scenes and head direction based on the historical firing rates of head direction cells, without relying on specific landmarks. It also introduced a method to fine-tune error correction by modulating the strength of self-motion input to control the movement speed of the head direction cell activity bump. Experimental results showed that this approach effectively reduced the accumulation of self-motion-related errors and significantly enhanced the accuracy and robustness of the navigation system. These findings offer a new perspective for biologically inspired robotic navigation systems and underscore the potential of neural mechanisms in enabling efficient and reliable autonomous navigation.
Animals
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Neural Networks, Computer
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Calibration
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Spatial Navigation/physiology*
;
Head Movements/physiology*
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Neurons/physiology*
;
Models, Neurological
;
Head/physiology*
;
Action Potentials/physiology*
3.Human Cortical Organoids with a Novel SCN2A Variant Exhibit Hyperexcitability and Differential Responses to Anti-Seizure Compounds.
Yuling YANG ; Yang CAI ; Shuyang WANG ; Xiaoling WU ; Zhicheng SHAO ; Xin WANG ; Jing DING
Neuroscience Bulletin 2025;41(11):2010-2024
Mutations in ion channel genes have long been implicated in a spectrum of epilepsy syndromes. However, therapeutic decision-making is relatively complex for epilepsies associated with channelopathy. Therefore, in the present study, we used a patient-derived organoid model with a novel SCN2A mutation (p.E512K) to investigate the potential of utilizing such a model as a platform for preclinical testing of anti-seizure compounds. The electrophysiological properties of the variant Nav1.2 exhibited gain-of-function effects with increased current amplitude and premature activation. Immunofluorescence staining of patient-derived cortical organoids (COs) displayed normal neurodevelopment. Multielectrode array (MEA) recordings of patient-derived COs showed hyperexcitability with increased spiking and remarkable network bursts. Moreover, the application of patient-derived COs for preclinical drug testing using the MEA showed that they exhibit differential responses to various anti-seizure drugs and respond well to carbamazepine. Our results demonstrate that the individualized organoids have the potential to serve as a platform for preclinical pharmacological assessment.
Organoids/physiology*
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NAV1.2 Voltage-Gated Sodium Channel/genetics*
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Humans
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Anticonvulsants/pharmacology*
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Epilepsy/drug therapy*
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Mutation
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Cerebral Cortex/drug effects*
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Action Potentials/drug effects*
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Carbamazepine/pharmacology*
4.Combined Study of Behavior and Spike Discharges Associated with Negative Emotions in Mice.
Jinru XIN ; Xinmiao WANG ; Xuechun MENG ; Ling LIU ; Mingqing LIU ; Huangrui XIONG ; Aiping LIU ; Ji LIU
Neuroscience Bulletin 2025;41(10):1843-1860
In modern society, people are increasingly exposed to chronic stress, leading to various mental disorders. However, the activities of brain regions, especially neural firing patterns related to specific behaviors, remain unclear. In this study, we introduce a novel approach, NeuroSync, which integrates open-field behavioral testing with electrophysiological recordings from emotion-related brain regions, specifically the central amygdala and the paraventricular nucleus of the hypothalamus, to explore the mechanisms of negative emotions induced by chronic stress in mice. By applying machine vision techniques, we quantified behaviors in the open field, and signal processing algorithms elucidated the neural underpinnings of the observed behaviors. Synchronizing behavioral and electrophysiological data revealed significant correlations between neural firing patterns and stress-related behaviors, providing insights into real-time brain activity underlying behavioral responses. This research combines deep learning and machine learning to synchronize high-resolution video and electrophysiological data, offering new insights into neural-behavioral dynamics under chronic stress conditions.
Animals
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Mice
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Male
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Emotions/physiology*
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Stress, Psychological/physiopathology*
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Action Potentials/physiology*
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Mice, Inbred C57BL
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Behavior, Animal/physiology*
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Machine Learning
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Amygdala/physiopathology*
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Neurons/physiology*
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Paraventricular Hypothalamic Nucleus/physiopathology*
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Brain/physiology*
5.Pre-action Neuronal Encoding of Task Situation Uncertainty in the Medial Prefrontal Cortex of Rats.
Qiulin HUA ; Yu PENG ; Jianyun ZHANG ; Baoming LI ; Jiyun PENG
Neuroscience Bulletin 2025;41(11):2036-2048
Humans and animals have a fundamental ability to use experiences and environmental information to organize behavior. It often happens that humans and animals make decisions and prepare actions under uncertain situations. Uncertainty would significantly affect the state of animals' minds, but may not be reflected in behavior. How to "read animals' mind state" under different situations is a challenge. Here, we report that neuronal activity in the medial prefrontal cortex (mPFC) of rats can reflect the environmental uncertainty when the task situation changes from certain to uncertain. Rats were trained to perform behavioral tasks under certain and uncertain situations. Under certain situations, rats were required to simply repeat two nose-poking actions that each triggered short auditory tone feedback (single-task situation). Whereas under the uncertain situation, the feedback could randomly be either the previous tone or a short musical rhythm. No additional action was required upon the music feedback, and the same secondary nose-poking action was required upon the tone feedback (dual-task situation); therefore, the coming task was uncertain before action initiation. We recorded single-unit activity from the mPFC when the rats were performing the tasks. We found that in the dual task, when uncertainty was introduced, many mPFC neurons were actively engaged in dealing with the uncertainty before the task initiation, suggesting that the rats could be aware of the task situation change and encode the information in the mPFC before the action of task initiation.
Animals
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Prefrontal Cortex/cytology*
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Uncertainty
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Neurons/physiology*
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Male
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Rats
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Rats, Long-Evans
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Action Potentials/physiology*
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Acoustic Stimulation
6.Functional and distinct roles of Piezo2-mediated mechanotransduction in dental primary afferent neurons.
Pa Reum LEE ; Kihwan LEE ; Ji Min PARK ; Shinae KIM ; Seog Bae OH
International Journal of Oral Science 2025;17(1):45-45
Piezo2, a mechanosensitive ion channel, serves as a crucial mechanotransducer in dental primary afferent (DPA) neurons and is potentially involved in hypersensitivity to mild mechanical irritations observed in dental patients. Given Piezo2's widespread expression across diverse subpopulations of DPA neurons, this study aimed to characterize the mechanosensory properties of Piezo2-expressing DPA neurons with a focus on distinct features of voltage-gated sodium channels (VGSCs) and neuropeptide profiles. Using whole-cell patch-clamp recordings, we observed mechanically activated action potentials (APs) and classified AP waveforms based on the presence or absence of a hump during the repolarization phase. Single-cell reverse transcription polymerase chain reaction combined with patch-clamp recordings revealed specific associations between AP waveforms and molecular properties, including tetrodotoxin-resistant VGSCs (NaV1.8 and NaV1.9) and TRPV1 expression. Reanalysis of the transcriptomic dataset of DPA neurons identified correlations between neuropeptides-including two CGRP isoforms (α-CGRP and β-CGRP), Substance P, and Galanin-and the expression of NaV1.8 and NaV1.9, which were linked to defined AP subtypes. These molecular associations were further validated in Piezo2+ DPA neurons using fluorescence in situ hybridization. Together, these findings highlight the electrophysiological and neurochemical heterogeneity of Piezo2-expressing DPA neurons and their specialized roles in distinct mechanosensory signal transmission.
Ion Channels/physiology*
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Mechanotransduction, Cellular/physiology*
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Animals
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Neurons, Afferent/metabolism*
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Patch-Clamp Techniques
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Mice
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TRPV Cation Channels/metabolism*
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Action Potentials
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Rats
7.The inverse stochastic resonance in a small-world neuronal network under electromagnetic stimulation.
Huilan YANG ; Shuxiang TIAN ; Haijun ZHU ; Guizhi XU
Journal of Biomedical Engineering 2023;40(5):859-866
Electromagnetic stimulation is an important neuromodulation technique that modulates the electrical activity of neurons and affects cortical excitability for the purpose of modulating the nervous system. The phenomenon of inverse stochastic resonance is a response mechanism of the biological nervous system to external signals and plays an important role in the signal processing of the nervous system. In this paper, a small-world neural network with electrical synaptic connections was constructed, and the inverse stochastic resonance of the small-world neural network under electromagnetic stimulation was investigated by analyzing the dynamics of the neural network. The results showed that: the Levy channel noise under electromagnetic stimulation could cause the occurrence of inverse stochastic resonance in small-world neural networks; the characteristic index and location parameter of the noise had significant effects on the intensity and duration of the inverse stochastic resonance in neural networks; the larger the probability of randomly adding edges and the number of nearest neighbor nodes in small-world networks, the more favorable the anti-stochastic resonance was; by adjusting the electromagnetic stimulation parameters, a dual regulation of the inverse stochastic resonance of the neural network can be achieved. The results of this study provide some theoretical support for exploring the regulation mechanism of electromagnetic nerve stimulation technology and the signal processing mechanism of nervous system.
Action Potentials/physiology*
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Computer Simulation
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Models, Neurological
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Stochastic Processes
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Neurons/physiology*
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Electromagnetic Phenomena
9.Bi-directional Control of Synaptic Input Summation and Spike Generation by GABAergic Inputs at the Axon Initial Segment.
Ziwei SHANG ; Junhao HUANG ; Nan LIU ; Xiaohui ZHANG
Neuroscience Bulletin 2023;39(1):1-13
Differing from other subtypes of inhibitory interneuron, chandelier or axo-axonic cells form depolarizing GABAergic synapses exclusively onto the axon initial segment (AIS) of targeted pyramidal cells (PCs). However, the debate whether these AIS-GABAergic inputs produce excitation or inhibition in neuronal processing is not resolved. Using realistic NEURON modeling and electrophysiological recording of cortical layer-5 PCs, we quantitatively demonstrate that the onset-timing of AIS-GABAergic input, relative to dendritic excitatory glutamatergic inputs, determines its bi-directional regulation of the efficacy of synaptic integration and spike generation in a PC. More specifically, AIS-GABAergic inputs promote the boosting effect of voltage-activated Na+ channels on summed synaptic excitation when they precede glutamatergic inputs by >15 ms, while for nearly concurrent excitatory inputs, they primarily produce a shunting inhibition at the AIS. Thus, our findings offer an integrative mechanism by which AIS-targeting interneurons exert sophisticated regulation of the input-output function in targeted PCs.
Axon Initial Segment
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Axons/physiology*
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Neurons
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Synapses/physiology*
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Pyramidal Cells/physiology*
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Interneurons/physiology*
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Action Potentials/physiology*
10.A comparative study of microwire electrode array with built-in and external reference electrodes.
Li-Na ZHANG ; Xiang-Xin DU ; Yu-Tong ZHANG ; Xia GUO ; Na HAO ; Xin ZHAO ; Yu ZHANG
Chinese Journal of Applied Physiology 2022;38(1):85-90
Objective: To compare the difference between the built-in and external reference electrode of microwire electrode array in the process of recording rat brain neuron firings, optimizing the production and embedding of the microwire electrode array, and providing a more affordable and excellent media tool for multi-channel electrophysiological real-time recording system. Methods: A 16 channel microwire electrode array was made by using nickel chromium alloy wires, circuit board, electrode pin and ground wires (silver wires). The reference electrode of the microwire electrode array was built-in (the reference electrode and electrode array were arranged in parallel) or external (the reference electrode and ground wire were welded at both ends of one side of the electrode), and the difference between the two electrodes was observed and compared in recording neuronal discharges in ACC brain area of rats. Experimental rats were divided into built-in group and external group, n=8-9. The test indicators included signal-to-noise ratio (n=8), discharge amplitude (n=380) and discharge frequency (n=54). Results: The microwire electrode array with both built-in and external reference electrodes successfully recorded the electrical signals of neurons in the ACC brain region of rats. Compared with the external group, the electrical signals of neurons in built-in group had the advantages of a higher signal-to-noise ratio (P<0.05), a smaller amplitude of background signals and less noise interference, and a larger discharge amplitude(P<0.05); there was no significant difference in spike discharge frequency recorded by these two types of electrodes (P>0.05). Conclusion: When recording the electrical activity of neurons in the ACC brain region of rats, the microwire electrode array with built-in reference electrode recorded electrical signals with higher signal-to-noise ratio and larger discharge amplitude, providing a more reliable tool for multi-channel electrophysiology technology.
Action Potentials/physiology*
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Animals
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Brain
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Electrophysiological Phenomena
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Microelectrodes
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Neurons
;
Rats

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