Changes In Neural Activity Research Articles

Gender Differences in Amplitude of Low‐Frequency Fluctuation Alterations in Healthy Volunteers by Acupuncture on Left “LI 15”: A Resting‐State fMRI Study

Objectives: This study is aimed at evaluating gender differences in neural activity change response to the acupuncture on left Jianyu (LI 15) in healthy volunteers.Methods: Forty healthy volunteers (20 males and 20 females) received 20‐min acupuncture on left LI 15 and underwent functional magnetic resonance imaging (fMRI) scans before and after acupuncture. Amplitude of low‐frequency fluctuations (ALFF) in the 0.01–0.08 Hz range were determined for both scans. Paired t‐tests were performed on ALFF between two scans separately for the male and female groups to identify neural changes related to acupuncture.Results: After acupuncture, males showed significantly increased ALFF in the left cerebellum and right angular gyrus but decreased ALFF in the left precentral gyrus, left inferior occipital gyrus, and right fusiform gyrus. However, the ALFF change in females is almost negligible.Conclusions: Brain functional activity in response to acupuncture on left LI 15 is noticeably different between males and females. This is preliminary evidence that gender may be an important factor for optimal clinically personalized acupuncture therapy for poststroke shoulder pain in the future.

Pre-supplementary Motor Cortex Mediates Learning Transfer from Perceptual to Motor Timing.

When we intensively train a timing skill, such as learning to play the piano, we not only produce brain changes associated with task-specific learning but also improve our performance in other temporal behaviors that depend on these tuned neural resources. Since the neural basis of time learning and generalization is still unknown, we measured the changes in neural activity associated with the transfer of learning from perceptual to motor timing in a large sample of subjects (n = 65; 39 women). We found that intense training in an interval discrimination task increased the acuity of time perception in a group of subjects that also exhibited learning transfer, expressed as a reduction in inter-tap interval variability during an internally driven periodic motor task. In addition, we found subjects with no learning and/or generalization effects. Notably, functional imaging showed an increase in pre-supplementary motor area and caudate-putamen activity between the post- and pre-training sessions of the tapping task. This increase was specific to the subjects that generalized their timing acuity from the perceptual to the motor context. These results emphasize the central role of the cortico-basal ganglia circuit in the generalization of timing abilities between tasks.

Developmental changes in neonatal hemodynamics during tactile stimulation using whole-head functional near-infrared spectroscopy

Neural-activity-associated hemodynamic changes have been used to noninvasively measure brain function in the early developmental stages. However, the temporal changes in their hemodynamics are not always consistent with adults. Studies have not evaluated developmental changes for a long period using the same stimuli; therefore, this study examined the normalized relative changes in oxygenated hemoglobin (Δ[oxy-Hb]) in full-term infants and compared them with neonates up to 10 months of age during the administration of tactile vibration stimuli to their limbs using whole-head functional near-infrared spectroscopy. The time to peak of normalized Δ[oxy-Hb] was not affected by age. The amplitude of normalized Δ[oxy-Hb] showed an effect of age in broader areas, including sensorimotor-related but excluding supplementary motor area; the amplitude of normalized Δ[oxy-Hb] decreased the most in the 1–2-month-old group and later increased with development. We hypothesized that these results may reflect developmental changes in neural activity, vasculature, and blood oxygenation.

Evaluating the impact of water reuse educational videos on water reuse perceptions using EEG/event related potential

As climate change and population growth increasingly stress freshwater resources, government agencies and scientists have recognized the importance of water reuse (the beneficial use of reclaimed or recycled water). While end users (municipalities and farmers) are largely open to exploring water reuse, a barrier to using this water source is the public's negative perception, or the ‘yuck factor’. Recognizing that water reuse is becoming a necessity, there is an urgent need to determine how to improve public acceptance of this water source. Increasing knowledge has been identified as a critical method for improving the adoption of sustainable practices, but to date, there has been a lack of outcome studies on the ability of water reuse education materials to change perceptions. Previous studies have relied heavily on self-reported concerns and perceptions which are limited by bias and social expectations, and their results have failed to substantially change water reuse education efforts, and by extension failed to substantially improve water reuse perceptions. We propose the integration of psychology for evaluating the effectiveness of water reuse education and outreach efforts. The purpose of this study was to determine if water reuse educational videos modulate perceptions of water reuse terms. Participants were recruited from a university campus and completed pre-intervention surveys on water reuse knowledge, willingness to use recycled water, and preferred water reuse information sources. We then measured changes in neural activity in response to multiple categories of water reuse terms pre- and post-exposure to water reuse education videos using electroencephalogram (EEG). Through EEG we measured event related potential (ERP), which assesses sustained engagement with the cues (late positive potential (LPP) amplitude), and alpha power. Participants also completed a pre/post exposure battery involving five tasks, in randomized order, presented before and after viewing videos. Sixty-eight percent of survey participants had previously heard of water reuse and 91% reported willingness to use recycled water for at least one activity. Participants reported obtaining water reuse information mostly from the internet (77%) and preferred to receive additional information mainly by watching online videos (73%). We observed significant increases in alpha power, corresponding to feelings of relaxation, in response to seven of eight water reuse term categories post-video exposure. These findings show that water reuse educational videos can change perceptions of water reuse. Our results point to the possibility of validating and increasing the effectiveness of water reuse education materials using sophisticated neurocognitive measures.

Tracking Cerebral Microvascular and Metabolic Parameters during Cardiac Arrest and Cardiopulmonary Resuscitation

Hemodynamic models provide a mathematical representation and computational framework that describe the changes in blood flow, blood volume, and oxygenation levels that occur in response to neural activity and systemic changes, while near-infrared spectroscopy (NIRS) measures deoxyhemoglobin, oxyhemoglobin, and other chromophores to analyze cerebral hemodynamics and metabolism. In this study, we apply a dynamic hemometabolic model to NIRS data acquired during cardiac arrest and cardiopulmonary resuscitation (CPR) in pigs. Our goals were to test the model’s ability to accurately describe the observed phenomena, to gain an understanding of the intricate behavior of cerebral microvasculature, and to compare the obtained parameters with known values. By employing the inverse of the hemometabolic model, we measured a range of significant physiological parameters, such as the rate of oxygen diffusion from blood to tissue, the arteriole and venule volume fractions, and the Fåhraeus factor. Statistical analysis uncovered significant differences in the baseline and post-cardiac arrest values of some of the parameters.

Artificial intelligence modelling human mental fatigue: A comprehensive survey

Mental fatigue refers to the decline in cognitive abilities that can occur as a result of prolonged mental exertion. Neuroscientists have been studying mental fatigue for a while. They clearly understand some underlying mechanisms of mental fatigue, such as brain chemistry and neural activity changes. However, defining mental fatigue is still an open research question. Despite this, neuroscience and cognitive psychology has made significant progress in understanding the causes and consequences of mental fatigue. In contrast, computer scientists presumably have a limited understanding of mental fatigue. This lack of understanding leads to inadequate models of mental fatigue in computer science. However, the ever evolving field of artificial intelligence (AI) shows a great potential to answer the open challenges in mental fatigue modelling. For instance, AI with fuzzy rules, machine learning or deep learning algorithms, as well as the methods of model explanation can be a valuable tool for creating accurate models of mental fatigue. Artificial intelligence models can learn from large amounts of data and accurately predict mental fatigue. However, modelling efforts are often more focused on acquiring parameters than studying and validating them within the model. Models developed in this way suffer problems with reliability making it challenging to understand the underlying causes of mental fatigue. Therefore, it is essential balance between these parameters’ correct acquisition, validation and interaction to create more accurate models of mental fatigue. In our survey, we have observed that an unspecified modelling impact the model at four scale : experimental design, data acquisition and processing, choice of indicators or parameters and reasoning. We provide some useful guidelines through criticisms for modelling, which would be closer to reality.

Prediction Of Seizures In Patients With Temporal Lobe Epilepsy, More Than 30 Minutes Before Onset.

Dear Madam, Around 52.5 million people worldwide suffer from the neurological illness known as epilepsy, which is frequently characterized by recurring seizures. (1, 2) As epilepsy is a chronic disorder that can lead to cognitive deficits, sadness, and anxiety in sufferers, it has a considerable negative impact on individuals and society. The most common type of seizures, affecting around 61% of persons with epilepsy, are focal seizures, which raise the risk of injury and early death (2). One of the most common forms of focal epilepsy, temporal lobe epilepsy (TLE), is characterized by recurring spontaneous seizures that begin in the temporal lobe. (s). (3) In the last two decades, many new antiseizure medications (ASMs)have been developed; however, about 40% of people with epilepsy may be drug-resistant, meaning ASMs are unable to control their seizures; therefore, despite the advent of new treatments, a high unmet need remains unaddressed. (2) Surgery is an alternate treatment, however, it cannot be used if larger areas of the brain are affected, in such cases, neuromodulation is a novel and successful therapeutic tool developed. (4) Conventionally, neural activity in epilepsy is categorized into interictal, and post-ictal states. With the help of continuous EEG, researchers have subdivided interictal state into a pre-ictal and pro-ictal state in temporal lobe epilepsy patients (which is the typical drug-resistant focal epilepsy targeted for interventions such as neuromodulation). The pre-ictal states indicate imminent seizure onset, while pro-ictal states reflect changes in neural activity that create a propensity for seizures over longer periods. The EEG-based pro-ictal state detection is critical to adaptive neuromodulation, with early detection of seizure allowing electrodes to be applied therapeutically to the brain's seizure onset zone and thalamus enabling treatment to be modified as per seizure risk. (5) A prospective cohort study was conducted on adults with drug-resistant temporal lobe epilepsy at UTHealth Houston, in which pro-ictal state – i.e., pathologic brain activities during periods of heightened seizure risk could be detected up to one-half hour prior to seizure onset. A classifier was developed that could reasonably accurately distinguish between physiological and pathologic brain states in temporal lobe epilepsy. Thalamocortical dynamics were used to identify pro-ictal states in each patient. As the limbic thalamus exerts a diverse influence on cortex activity, thalamocortical EEG was used for pro-ictal state detection as opposed to previous paradigms derived solely from cortical structures. ---Continue

Ghrelin signalling in AgRP neurons links metabolic state to the sensory regulation of AgRP neural activity

ObjectiveThe sensory detection of food and food cues suppresses Agouti related peptide (AgRP) neuronal activity prior to consumption with greatest suppression occurring in response to highly caloric food or interoceptive energy need. However, the interoceptive mechanisms priming an appropriate AgRP neural response to external sensory information of food availability remain unexplored. Since hunger increases plasma ghrelin, we hypothesized that ghrelin receptor (GHSR) signalling on AgRP neurons is a key interoceptive mechanism integrating energy need with external sensory cues predicting caloric availability. MethodsWe used in vivo photometry to measure the effects of ghrelin administration or fasting on AgRP neural activity with GCaMP6s and dopamine release in the nucleus accumbens with GRAB-DA in mice lacking ghrelin receptors in AgRP neurons. ResultsThe deletion of GHSR on AgRP neurons prevented ghrelin-induced food intake, motivation and AgRP activity. The presentation of food (peanut butter pellet) or a wooden dowel suppressed AgRP activity in fasted WT but not mice lacking GHSRs in AgRP neurons. Similarly, peanut butter and a wooden dowel increased dopamine release in the nucleus accumbens after ip ghrelin injection in WT but not mice lacking GHSRs in AgRP neurons. No difference in dopamine release was observed in fasted mice. Finally, ip ghrelin administration did not directly increase dopamine neural activity in the ventral tegmental area. ConclusionsOur results suggest that AgRP GHSRs integrate an interoceptive state of energy need with external sensory information to produce an optimal change in AgRP neural activity. Thus, ghrelin signalling on AgRP neurons is more than just a feedback signal to increase AgRP activity during hunger.

Correlation between contractile properties of quadriceps muscle and functional performance in runners with patellofemoral pain syndrome

Background: Long distance runners commonly complain from patellofemoral pain syndrome (PFPS) that limits their performance and return to sport. Abnormal neuromuscular control of the quadriceps has been demonstrated to cause patellar mal-tracking and hence PFPS. Changes in muscle morphology and neural activity have a role in neuromuscular changes, a key contributor to either primary or secondary injuries. Poor landing mechanics, impaired postural control, as well as changed peripheral muscle activation are all clinical manifestations of neuromuscular control deficiencies caused by central nervous system defects that have a deleterious effect on the contractile characteristics of skeletal muscle. Objectives: The purpose of this study was to investigate the correlation between contractile properties of quadriceps muscle and functional performance in long distance runners with PFPS. Study design: Cross-sectional study. Methods: Thirty runners were recruited form multiple Egyptian clubs. Tensiomyography (TMG) Parameters were assessed regarding Contraction time (Tc), Maximal displacement (Dm), Sustain time (Ts), Relaxion time (Tr) and Delay time (Td) in Rectus femoris (RF), Vastus medialis (VM) and Vastus lateralis (VL) separately and correlated with functional performance; number of repetitions in 30 seconds for anteromedial lunge test, balance and reach test and step-down test. Outcome measures: Functional performance was measured using functional performance tests; anteromedial lunge test, balance and reach test and step-down test. Results: It was found that VM Tc, VL Dm, were moderately positively correlated with anteromedial lunge (r = 0.583, 0.404, p<0.05) respectively. In contrast, RF Tr was negatively correlated with anteromedial lunge (-0.364, p<0.05); VM Ts,Tr,Dm; VL Td were moderately negatively correlated with balance and reach (r = --0.577, -0.388, 0.655 and -0.385, respectively, p<0.05). In contrast, VL Tc was moderately positively correlated with step-down (r = 0.424, p = 0.019). Conclusion: All contractile properties of quadriceps muscle are significantly correlated with functional performance in long distance runners with PFPS. Future studies should address these properties, using proper rehabilitation strategies, to improve performance of runners with PFPS.

A dataset of Chinese reading and brain development for children and adolescents

As a fundamental skill for children and adolescents, reading plays a crucial role in knowledge acquisition and cognitive development. Improving reading skills among children and adolescents is also the cornerstone of China’s national reading strategy. The rapid development of reading ability of children and adolescents coincides with their rapid brain development. Throughout the process of gradually acquiring reading skills, children and adolescents undergo various changes in neural activity and behavioral performance. However, the relationship between reading development and brain neurodevelopment of the brain still remains largely unknown. This paper offers valuable resources, including resting-state functional magnetic resonance imaging data, structural magnetic resonance imaging data, and comprehensive neuropsychological data from assessments of reading and cognitive-related tests in school-aged children and adolescents. It also includes preprocessed magnetic resonance imaging data, quality control report and description file. These valuable resources can significantly contribute to further scientific research in the field of neurodevelopment of reading in young individuals.

The changes of neuroactivity of Tui Na (Chinese massage) at Hegu acupoint on sensorimotor cortex in stroke patients with upper limb motor dysfunction: a fNIRS study

BackgroundTui Na (Chinese massage) is a relatively simple, inexpensive, and non-invasive intervention, and has been used to treat stroke patients for many years in China. Tui Na acts on specific parts of the body which are called meridians and acupoints to achieve the role of treating diseases. Yet the underlying neural mechanism associated with Tui Na is not clear due to the lack of detection methods.ObjectiveFunctional near-infrared spectroscopy (fNIRS) was used to explore the changes of sensorimotor cortical neural activity in patients with upper limb motor dysfunction of stroke and healthy control groups during Tui Na Hegu Point.MethodsTen patients with unilateral upper limb motor dysfunction after stroke and eight healthy subjects received Tui Na. fNIRS was used to record the hemodynamic data in the sensorimotor cortex and the changes in blood flow were calculated based on oxygenated hemoglobin (Oxy-Hb), the task session involved repetitive Tui Na on Hegu acupoint, using a block design [six cycles: rest (20 seconds); Tui Na (20 seconds); rest (30 seconds)]. The changes in neural activity in sensorimotor cortex could be inferred according to the principle of neurovascular coupling, and the number of activated channels in the bilateral hemisphere was used to calculate the lateralization index.Result1. For hemodynamic response induced by Hegu acupoint Tui Na, a dominant increase in the contralesional primary sensorimotor cortex during Hegu point Tui Na of the less affected arm in stroke patients was observed, as well as that in healthy controls, while this contralateral pattern was absent during Hegu point Tui Na of the affected arm in stroke patients. 2. Concerning the lateralization index in stroke patients, a significant difference was observed between lateralization index values for the affected arm and the less affected arm (P < 0.05). Wilcoxon tests showed a significant difference between lateralization index values for the affected arm in stroke patients and lateralization index values for the dominant upper limb in healthy controls (P < 0.05), and no significant difference between lateralization index values for the less affected arm in stroke patients and that in healthy controls (P = 0.36).ConclusionThe combination of Tui Na and fNIRS has the potential to reflect the functional status of sensorimotor neural circuits. The changes of neuroactivity in the sensorimotor cortex when Tui Na Hegu acupoint indicate that there is a certain correlation between acupoints in traditional Chinese medicine and neural circuits.

Mediodorsal thalamus-projecting anterior cingulate cortex neurons modulate helping behavior in mice

Many species living in groups can perform prosocial behaviors via voluntarily helping others with or without benefits for themselves. To provide a better understanding of the neural basis of such prosocial behaviors, we adapted a preference lever-switching task in which mice can prevent harm to others by switching from using a lever that causes shocks to a conspecific one that does not. We found the harm avoidance behavior was mediated by self-experience and visual and social contact but not by gender or familiarity. By combining single-unit recordings and analysis of neural trajectory decoding, we demonstrated the dynamics of anterior cingulate cortex (ACC) neural activity changes synchronously with the harm avoidance performance of mice. In addition, ACC neurons projected to the mediodorsal thalamus (MDL) to modulate the harm avoidance behavior. Optogenetic activation of the ACC-MDL circuit during non-preferred lever pressing (nPLP) and inhibition of this circuit during preferred lever pressing (PLP) both resulted in the loss of harm avoidance ability. This study revealed the ACC-MDL circuit modulates prosocial behavior to avoid harm to conspecifics and may shed light on the treatment of neuropsychiatric disorders with dysfunction of prosocial behavior.

Dynamic organization of cerebellar climbing fiber response and synchrony in multiple functional components reduces dimensions for reinforcement learning.

Cerebellar climbing fibers convey diverse signals, but how they are organized in the compartmental structure of the cerebellar cortex during learning remains largely unclear. We analyzed a large amount of coordinate-localized two-photon imaging data from cerebellar Crus II in mice undergoing 'Go/No-go' reinforcement learning. Tensor component analysis revealed that a majority of climbing fiber inputs to Purkinje cells were reduced to only four functional components, corresponding to accurate timing control of motor initiation related to a Go cue, cognitive error-based learning, reward processing, and inhibition of erroneous behaviors after a No-go cue. Changes in neural activities during learning of the first two components were correlated with corresponding changes in timing control and error learning across animals, indirectly suggesting causal relationships. Spatial distribution of these components coincided well with boundaries of Aldolase-C/zebrin II expression in Purkinje cells, whereas several components are mixed in single neurons. Synchronization within individual components was bidirectionally regulated according to specific task contexts and learning stages. These findings suggest that, in close collaborations with other brain regions including the inferior olive nucleus, the cerebellum, based on anatomical compartments, reduces dimensions of the learning space by dynamically organizing multiple functional components, a feature that may inspire new-generation AI designs.

Laminar pattern of adolescent development changes in working memory neuronal activity.

Adolescent development is characterized by an improvement in cognitive abilities, such as working memory. Neurophysiological recordings in a nonhuman primate model of adolescence have revealed changes in neural activity that mirror improvement in behavior, including higher firing rate during the delay intervals of working memory tasks. The laminar distribution of these changes is unknown. By some accounts, persistent activity is more pronounced in superficial layers, so we sought to determine whether changes are most pronounced there. We therefore analyzed neurophysiological recordings from the young and adult stage of male monkeys, at different cortical depths. Superficial layers exhibited an increased baseline firing rate in the adult stage. Unexpectedly, we also detected substantial increases in delay period activity in the middle layers after adolescence, which was confirmed even after excluding penetrations near sulci. Finally, improved discriminability around the saccade period was most evident in the deeper layers. These results reveal the laminar pattern of neural activity maturation that is associated with cognitive improvement.NEW & NOTEWORTHY Structural brain changes are evident during adolescent development particularly in the cortical thickness of the prefrontal cortex, at a time when working memory ability increases markedly. The depth distribution of neurophysiological changes during adolescence is not known. Here, we show that neurophysiological changes are not confined to superficial layers, which have most often been implicated in the maintenance of working memory. Contrary to expectations, substantial changes were evident in intermediate layers of the prefrontal cortex.

Evaluation of neurotoxicity for pesticide-related compounds in human iPS cell-derived neurons using microelectrode array

In vivo evaluations of chemicals in neurotoxicity have certain limitations due to the considerable time and cost required, necessity of extrapolation from rodents to humans, and limited information on toxicity mechanisms. To address this issue, the development of in vitro test methods using new approach methodologies (NAMs) is important to evaluate the chemicals in neurotoxicity. Microelectrode array (MEA) allows the assessment of changes in neural network activity caused by compound administration. However, studies on compound evaluation criteria are scarce. In this study, we evaluated the impact of pesticides on neural activity using MEA measurements of human iPSC-derived neurons. A principal component analysis was performed on the electrical physiological parameters obtained by MEA measurements, and the influence of excessive neural activity due to compound addition was defined using the standard deviation of neural activity with solvent addition as the reference. By using known seizurogenic compounds as positive controls for neurotoxicity in MEA and evaluating pesticides with insufficient verification of their neurotoxicity in humans, we demonstrated that these pesticides exhibit neurotoxicity in humans. In conclusion, our data suggest that the neurotoxicity evaluation method in human iPSC neurons using MEA measurements could be one of the in vitro neurotoxicity test methods that could replace animal experiments.

Neural Encoding of Pavement Textures during Exoskeleton Control: A Pilot Study

This paper investigates the changes in sensory neural activity during exoskeleton control. Exoskeletons are becoming reliable tools for neurorehabilitation, as recent studies have shown that their use enhances neural plasticity. However, the specific neural correlates associated with exoskeleton control have not yet been described in detail. Therefore, in this pilot study, our aim was to investigate the effects of different pavement textures on the neural signals of participants (n = 5) while controlling a lower limb ExoAtlet®-powered exoskeleton. Subjects were instructed to walk on various types of pavements, including a flat surface, carpet, foam, and rubber circles, both with and without the exoskeleton. This setup resulted in eight different experimental conditions for classification (i.e., Exoskeleton/No Exoskeleton in one of four different pavements). Four-minute Electroencephalography (EEG) signals were recorded in each condition: (i) the power of the signals was compared for electrodes C3 and C4 across different conditions (Exoskeleton/No Exoskeleton on different pavements), and (ii) the signals were classified using four models: the linear support vector machine (L-SVM), the K-nearest neighbor algorithm (KNN), linear discriminant analysis (LDA), and the artificial neural network (ANN). the results of power analysis showed increases and decreases in power within the delta frequency bands in electrodes C3 and C4 across the various conditions. The results of comparison between classifiers revealed that LDA exhibited the highest performance with an accuracy of 85.71%. These findings support the notion that the sensory processing of pavement textures during exoskeleton control is associated with changes in the delta band of the C3 and C4 electrodes. From the results, it is concluded that the use of classifiers, such as LDA, allow for a better offline classification of different textures in EEG signals, with and without exoskeleton control, than the analysis of power in different frequency bands.

Paving the Way for Memory Enhancement: Development and Examination of a Neurofeedback System Targeting the Medial Temporal Lobe.

Neurofeedback (NF) shows promise in enhancing memory, but its application to the medial temporal lobe (MTL) still needs to be studied. Therefore, we aimed to develop an NF system for the memory function of the MTL and examine neural activity changes and memory task score changes through NF training. We created a memory NF system using intracranial electrodes to acquire and visualise the neural activity of the MTL during memory encoding. Twenty trials of a tug-of-war game per session were employed for NF and designed to control neural activity bidirectionally (Up/Down condition). NF training was conducted with three patients with drug-resistant epilepsy, and we observed an increasing difference in NF signal between conditions (Up-Down) as NF training progressed. Similarities and negative correlation tendencies between the transition of neural activity and the transition of memory function were also observed. Our findings demonstrate NF's potential to modulate MTL activity and memory encoding. Future research needs further improvements to the NF system to validate its effects on memory functions. Nonetheless, this study represents a crucial step in understanding NF's application to memory and provides valuable insights into developing more efficient memory enhancement strategies.

Brain rhythms control microglial response and cytokine expression via NF-κB signaling.

Microglia transform in response to changes in sensory or neural activity, such as sensory deprivation. However, little is known about how specific frequencies of neural activity, or brain rhythms, affect microglia and cytokine signaling. Using visual noninvasive flickering sensory stimulation (flicker) to induce electrical neural activity at 40 hertz, within the gamma band, and 20 hertz, within the beta band, we found that these brain rhythms differentially affect microglial morphology and cytokine expression in healthy animals. Flicker induced expression of certain cytokines independently of microglia, including interleukin-10 and macrophage colony-stimulating factor. We hypothesized that nuclear factor κB (NF-κB) plays a causal role in frequency-specific cytokine and microglial responses because this pathway is activated by synaptic activity and regulates cytokines. After flicker, phospho-NF-κB colabeled with neurons more than microglia. Inhibition of NF-κB signaling down-regulated flicker-induced cytokine expression and attenuated flicker-induced changes in microglial morphology. These results reveal a mechanism through which brain rhythms affect brain function by altering microglial morphology and cytokines via NF-κB.

Mapping Pharmacologically Evoked Neurovascular Activation and Its Suppression in a Rat Model of Tremor Using Functional Ultrasound: A Feasibility Study.

Functional ultrasound (fUS), an emerging hemodynamic-based functional neuroimaging technique, is especially suited to probe brain activity and primarily used in animal models. Increasing use of pharmacological models for essential tremor extends new research to the utilization of fUS imaging in such models. Harmaline-induced tremor is an easily provoked model for the development of new therapies for essential tremor (ET). Furthermore, harmaline-induced tremor can be suppressed by the same classic medications used for essential tremor, which leads to the utilization of this model for preclinical testing. However, changes in local cerebral activities under the effect of tremorgenic doses of harmaline have not been completely investigated. In this study, we explored the feasibility of fUS imaging for visualization of cerebral activation and deactivation associated with harmaline-induced tremor and tremor-suppressing effects of propranolol. The spatial resolution of fUS using a high frame rate imaging enabled us to visualize time-locked and site-specific changes in cerebral blood flow associated with harmaline-evoked tremor. Intraperitoneal administration of harmaline generated significant neural activity changes in the primary motor cortex and ventrolateral thalamus (VL Thal) regions during tremor and then gradually returned to baseline level as tremor subsided with time. To the best of our knowledge, this is the first functional ultrasound study to show the neurovascular activation of harmaline-induced tremor and the therapeutic suppression in a rat model. Thus, fUS can be considered a noninvasive imaging method for studying neuronal activities involved in the ET model and its treatment.

Intermittent energy restriction changes the regional homogeneity of the obese human brain.

Intermittent energy restriction (IER) is an effective weight loss strategy. However, the accompanying changes in spontaneous neural activity are unclear, and the relationship among anthropometric measurements, biochemical indicators, and adipokines remains ambiguous. Thirty-five obese adults were recruited and received a 2-month IER intervention. Data were collected from anthropometric measurements, blood samples, and resting-state functional magnetic resonance imaging at four time points. The regional homogeneity (ReHo) method was used to explore the effects of the IER intervention. The relationships between the ReHo values of altered brain regions and changes in anthropometric measurements, biochemical indicators, and adipokines (leptin and adiponectin) were analyzed. Results showed that IER significantly improved anthropometric measurements, biochemical indicators, and adipokine levels in the successful weight loss group. The IER intervention for weight loss was associated with a significant increase in ReHo in the bilateral lingual gyrus, left calcarine, and left postcentral gyrus and a significant decrease in the right middle temporal gyrus and right cerebellum (VIII). Follow-up analyses showed that the increase in ReHo values in the right LG had a significant positive correlation with a reduction in Three-factor Eating Questionnaire (TFEQ)-disinhibition and a significant negative correlation with an increase in TFEQ-cognitive control. Furthermore, the increase in ReHo values in the left calcarine had a significant positive correlation with the reduction in TFEQ-disinhibition. However, no significant difference in ReHo was observed in the failed weight loss group. Our study provides objective evidence that the IER intervention reshaped the ReHo of some brain regions in obese individuals, accompanied with improved anthropometric measurements, biochemical indicators, and adipokines. These results illustrated that the IER intervention for weight loss may act by decreasing the motivational drive to eat, reducing reward responses to food cues, and repairing damaged food-related self-control processes. These findings enhance our understanding of the neurobiological basis of IER for weight loss in obesity.