Cerebral Regions Research Articles

Inhibition of Indoleamine 2,3-Dioxygenase Exerts Antidepressant-like Effects through Distinct Pathways in Prelimbic and Infralimbic Cortices in Rats under Intracerebroventricular Injection with Streptozotocin.

The application of intracerebroventricular injection of streptozotocin (ICV-STZ) is considered a useful animal model to mimic the onset and progression of sporadic Alzheimer's disease (sAD). In rodents, on day 7 of the experiment, the animals exhibit depression-like behaviors. Indoleamine 2,3-dioxygenase (IDO), a rate-limiting enzyme catalyzing the conversion of tryptophan (Trp) to kynurenine (Kyn), is closely related to depression and AD. The present study aimed to investigate the pathophysiological mechanisms of preliminary depression-like behaviors in ICV-STZ rats in two distinct cerebral regions of the medial prefrontal cortex, the prelimbic cortex (PrL) and infralimbic cortex (IL), both presumably involved in AD progression in this model, with a focus on IDO-related Kyn pathways. The results showed an increased Kyn/Trp ratio in both the PrL and IL of ICV-STZ rats, but, intriguingly, abnormalities in downstream metabolic pathways were different, being associated with distinct biological effects. In the PrL, the neuroprotective branch of the Kyn pathway was attenuated, as evidenced by a decrease in the kynurenic acid (KA) level and Kyn aminotransferase II (KAT II) expression, accompanied by astrocyte alterations, such as the decrease in glial fibrillary acidic protein (GFAP)-positive cells and increase in morphological damage. In the IL, the neurotoxicogenic branch of the Kyn pathway was enhanced, as evidenced by an increase in the 3-hydroxy-kynurenine (3-HK) level and kynurenine 3-monooxygenase (KMO) expression paralleled by the overactivation of microglia, reflected by an increase in ionized calcium-binding adaptor molecule 1 (Iba1)-positive cells and cytokines with morphological alterations. Synaptic plasticity was attenuated in both subregions. Additionally, microinjection of the selective IDO inhibitor 1-Methyl-DL-tryptophan (1-MT) in the PrL or IL alleviated depression-like behaviors by reversing these different abnormalities in the PrL and IL. These results suggest that the antidepressant-like effects linked to Trp metabolism changes induced by 1-MT in the PrL and IL occur through different pathways, specifically by enhancing the neuroprotective branch in the PrL and attenuating the neurotoxicogenic branch in the IL, involving distinct glial cells.

The relationship between computational thinking and mental rotation ability: a functional near-infrared spectroscopy study

ABSTRACT This study investigates the correlation between computational thinking (CT) skills and mental rotation ability, utilizing functional near-infrared spectroscopy (fNIRS) to assess neural efficiency as a potential underlying factor. We divided 38 participants into groups with high and low CT skills to perform mental rotation tasks. Prefrontal brain activity was monitored via a 48-channel fNIRS system. The experimental results suggested that participants possessing superior CT skills exhibited enhanced performance on the mental rotation test, accompanied by a higher neural efficiency index in the specified cerebral regions, as denoted by reduced oxygen consumption. This implies that individuals endowed with advanced CT capabilities can process information with greater efficacy, thereby attaining superior performance utilising lesser cognitive exertion. Our study offers some of the first empirical evidence regarding the neural basis underlying the relationship between CT skills and mental rotation ability in undergraduate students.

Alcohol Toxicity in the Developing Cerebellum.

The impact of ethanol on the fetus is a significant concern as an estimated 2-5% of live births may be affected by prenatal alcohol exposure. This exposure can lead to various functional and structural abnormalities in the cerebral cortex, basal ganglia, diencephalon, and cerebellum, resulting in region-specific symptoms. The deficits relate to the motor and cognitive domains, affecting, in particular, general intelligence, attention, executive functions, language, memory, visual perception, and social skills-collectively called the fetal alcohol spectrum disorder (FASD). Recent studies suggest that damage to the developing cerebellum (in form of alcohol exposure) can impair the cortical targets of the cerebello-thalamo-cortical tract. This malfunction in the cerebello-cerebral loop optimization may be due to disruptions in the formation of the foundational elements of the internal model within the developing cerebellum. Alcohol exposure targets multiple nodes in the reciprocal loops between the cerebellum and cerebral cortex. Here, we examine the possibility that prenatal alcohol exposure damages the developing cerebellum and disrupts the connectivity within the cerebello-cerebral neuronal circuits, exacerbating FASD-related cortical dysfunctions. We propose that malfunctions between cerebellar internal model (critically involved in predictions) and cerebral regions contribute to the deficits observed in FASD. Given the major role of the cerebellum in motor, cognitive, and affective functions, we suggest that therapies should target these malfunctions to mitigate the burden of FASD. We discuss the concept of therapies oriented towards malfunctioning cerebello-cerebral loops (TOMCCLs), emphasizing anti-inflammatory strategies and treatments aimed at modulating cerebellar myelination to restore optimal and predictive cerebello-cerebral functions.

Neuroprotective Role of Phytoconstituents-based Nanoemulsion for the Treatment of Alzheimer's Disease.

Alzheimer's disease (AD) is the most prevalent form of neurodegenerative disorder (ND), affecting more than 44 million individuals globally as of 2023. It is characterized by cognitive dysfunction and an inability to perform daily activities. The progression of AD is associated with the accumulation of amyloid beta (Aβ), the formation of neurofibrillary tangles (NFT), increased oxidative stress, neuroinflammation, mitochondrial dysfunction, and endoplasmic reticulum stress. Presently, various phytomedicines and their bioactive compounds have been identified for their neuroprotective effects in reducing oxidative stress, alleviating neuroinflammation, and mitigating the accumulation of Aβ and acetylcholinesterase enzymes in the hippocampus and cerebral cortex regions of the brain. However, despite demonstrating promising anti-Alzheimer's effects, the clinical utilization of phytoconstituents remains limited in scope. The key factor contributing to this limitation is the challenges inherent in traditional drug delivery systems, which impede their effectiveness and efficiency. These difficulties encompass insufficient drug targeting, restricted drug solubility and stability, brief duration of action, and a lack of control over drug release. Consequently, these constraints result in diminished bioavailability and insufficient permeability across the blood-brain barrier (BBB). In response to these challenges, novel drug delivery systems (NDDS) founded on nanoformulations have emerged as a hopeful strategy to augment the bioavailability and BBB permeability of bioactive compounds with poor solubility. Among these systems, nanoemulsion (NE) have been extensively investigated for their potential in targeting AD. NE offers several advantages, such as ease of preparation, high drug loading, and high stability. Due to their nanosize droplets, NE also improves gut and BBB permeability leading to enhanced permeability of the drug in systemic circulation and the brain. Various studies have reported the testing of NE-based phytoconstituents and their bioactives in different animal species, including transgenic, Wistar, and Sprague-Dawley (SD) rats, as well as mice. However, transgenic mice are commonly employed in AD research to analyze the effects of Aβ. In this review, various aspects such as the neuroprotective role of various phytoconstituents, the challenges associated with conventional drug delivery, and the need for NDDS, particularly NE, are discussed. Various studies involving phytoconstituent-based NE for the treatment of AD are also discussed.

Increased Functional Connectivity Between the Parietal and Occipital Modules Among Flight Cadets.

INTRODUCTION: Modular organization in brain regions often performs specific biological functions and is largely based on anatomically and/or functionally related brain areas. The current study aimed to explore changes in whole-brain modular organization affected by flight training.METHODS: The study included 25 male flight cadets and 24 male controls. The first assessment was performed in 2019, when the subjects were university freshmen. The second assessment was completed in 2022. High spatial resolution structural imaging (T1) and resting-state functional MRI data were collected. Then, 90 cerebral regions were organized into 6 brain modules. The intensity of intra- and intermodular communication was calculated.RESULTS: Mixed-effect regression model analysis identified significantly increased interconnections between the parietal and occipital modules in the cadet group, but significantly decreased interconnections in the control group. This change was largely attributed to flight training.DISCUSSION: Pilots need to control the aircraft (e.g., attitude, heading, etc.) using the stick and pedal in response to the current state of the aircraft displayed by the instrument panel; as such, flying requires a large amount of hand-eye coordination. Day-to-day flight training appeared to intensify the connection between the parietal and occipital modules among cadets.Chen X, Jiang H, Meng Y, Xu Z, Luo C. Increased functional connectivity between the parietal and occipital modules among flight cadets. Aerosp Med Hum Perform. 2024; 95(7):375-380.

Brain regions differences in amyloid-β and gene expression in early APP/PS1 mice and identification of Npas4 as a key molecule in Alzheimer's disease.

Distinct brain regions are differentially affected during the various stages of Alzheimer's disease (AD). While the hippocampus and cortex are known to play significant roles, the involvement of the cerebellum has received less attention. Understanding the changes in diverse brain regions is essential to unravel the neuropathological mechanism in early-stage AD. Our research aimed to explore and compare amyloid-β (Aβ) pathology and gene expression profiles across the hippocampus, cortex, and cerebellum in the early stages of the Amyloid Precursor Protein/Presenilin-1 (APP/PS1) mouse model. By 7 months of age, significant Aβ plaque accumulation was observed in the hippocampus and cortex of APP/PS1 mice, while no such deposits were found in the cerebellum. Gene expression analysis revealed predominant effects on immune response pathways in the hippocampus and cortex. Even in the absence of Aβ deposition, notable gene expression changes were observed in the cerebellum of APP/PS1 mice. Intriguingly, Neuronal PAS Domain protein 4 (Npas4) expression was consistently down-regulated across all brain regions, independent of Aβ plaque presence. Our findings reveal distinct transcriptomic alterations and Aβ pathology in select cerebral regions during the initial phase of AD. Notably, the diminished expression of the Npas4 across three brain regions implies that Npas4 could play a pivotal role in the early pathogenesis of AD.

Application of HFO and scaling analysis of neuronal oscillations in the presurgical evaluation of focal epilepsy

PurposeTo explore the utility of high frequency oscillations (HFO) and long-range temporal correlations (LRTCs) in preoperative assessment of epilepsy. MethodsMEG ripples were detected in 59 drug-resistant epilepsy patients, comprising 5 with parietal lobe epilepsy (PLE), 21 with frontal lobe epilepsy (FLE), 14 with lateral temporal lobe epilepsy (LTLE), and 19 with mesial temporal lobe epilepsy (MTLE) to identify the epileptogenic zone (EZ). The results were compared with clinical MEG reports and resection area. Subsequently, LRTCs were quantified at the source-level by detrended fluctuation analysis (DFA) and life/waiting -time at 5 bands for 90 cerebral cortex regions. The brain regions with larger DFA exponents and standardized life-waiting biomarkers were compared with the resection results. ResultsCompared to MEG sensor-level data, ripple sources were more frequently localized within the resection area. Moreover, source-level analysis revealed a higher proportion of DFA exponents and life-waiting biomarkers with relatively higher rankings, primarily distributed within the resection area (p<0.01). Moreover, these two LRCT indices across five distinct frequency bands correlated with EZ. ConclusionHFO and source-level LRTCs are correlated with EZ. Integrating HFO and LRTCs may be an effective approach for presurgical evaluation of epilepsy.

Very low levels of ABCA7 in the cerebrum and Alzheimer's disease onset between the ages of 60 and 80 independently of APOE.

This cross-sectional study addressed the ABCA7-Alzheimer's disease (AD) association. ABCA7 protein levels were quantified in 3 cerebral regions of brain donors with Braak neurofibrillary tangle (NFT) stages 0-V. Ordinal regression models were implemented to estimate the effect of ABCA7 on stopping in an earlier Braak NFT stage versus progressing to the later stages in 2 prespecified age segments. In the final model, high ABCA7 levels in the parietal cortex increased the odds of remaining cognitively healthy (ie, in stages 0/I) versus experiencing AD onset (ie, progressing to stages II-V) in the 61-80 age segment (OR = 2.87, adj 95% CI = 1.41-7.86, adj P = .007, n = 109), after controlling for APOE and other covariates. No ABCA7-AD association was found in the 81-98 age segment (n = 113). Parietal ABCA7 levels in 61-80-year-old with stages II-V were very low, even significantly lower than in 81-98-year-old with stages II-V. ABCA7 levels in the prefrontal cortex and hippocampus predicted AD onset in the 61-80 age segment after adjustment for APOE. ABCA7 levels were also the lowest in 61-80-year-old with frequent neuritic plaques. Thus, very low ABCA7 levels in the cerebrum are associated with AD onset in the 7th-8th decade of life.

Review on Study of Nanoparticles in Brain Targeting for Treatment Of Alzheimer’s

Alzheimer’s disease (AD) is an irreversible neurodegenerative disorder, in which there is a progressive deterioration of intellectual and social functions, memory loss, personality changes and inability for self-care, and has become the fourth leading cause of death in developed countries. Pathogenesis of AD, there is a progressive deposition of β-amyloid (Aβ)- peptide in the hippocampal and cerebral cortical regions. This deposition is associated with the presence of neurofibrillary tangles (NFTs) and senile plaques. The senile plaques deposited between the neurons consist mainly protein β amyloid. Neurofibrillary tangles deposited inside the neurons fabricated from Tau protein. Diagnosing Alzheimer's requires careful medical evaluation thorough medical history, mental status testing, physical and neurological examination tests (such as blood tests and brain imaging), two classes of medications approved to treat AD. Cholinesterase inhibitors: Donepezil, Rivastigmine, Galantamine, NMDA receptor antagonists: Memantine. The major goal in designing nanoparticles as a delivery system are to control particle size, surface property and release of pharmacologically active agents in order to achieve the site-specific action of the drug at the therapeutic optimum rate and dose regimen of the agent to the CNS, but also the ability of the agent to access the relevant target site within the CNS. Many strategies have been developed to deliver the drug into brain by crossing the BBB: chemical delivery systems, magnetic drug targeting or drug carrier systems such as antibodies, liposomes or nanoparticles. Among those, nanoparticles have got a great concentration as the potential targeted drug delivery systems in the brain recently. Keywords: Alzheimer’s disease, β-amyloid, cholinesterase inhibitors, Curcumin nanoparticles.

A Narrative Review of the Dorsal Root Ganglia and Spinal Cord Mechanisms of Action of Neuromodulation Therapies in Neuropathic Pain.

Neuropathic pain arises from injuries to the nervous system in diseases such as diabetes, infections, toxicity, and traumas. The underlying mechanism of neuropathic pain involves peripheral and central pathological modifications. Peripheral mechanisms entail nerve damage, leading to neuronal hypersensitivity and ectopic action potentials. Central sensitization involves a neuropathological process with increased responsiveness of the nociceptive neurons in the central nervous system (CNS) to their normal or subthreshold input due to persistent stimuli, leading to sustained electrical discharge, synaptic plasticity, and aberrant processing in the CNS. Current treatments, both pharmacological and non-pharmacological, aim to alleviate symptoms but often face challenges due to the complexity of neuropathic pain. Neuromodulation is emerging as an important therapeutic approach for the treatment of neuropathic pain in patients unresponsive to common therapies, by promoting the normalization of neuronal and/or glial activity and by targeting cerebral cortical regions, spinal cord, dorsal root ganglia, and nerve endings. Having a better understanding of the efficacy, adverse events and applicability of neuromodulation through pre-clinical studies is of great importance. Unveiling the mechanisms and characteristics of neuromodulation to manage neuropathic pain is essential to understand how to use it. In the present article, we review the current understanding supporting dorsal root ganglia and spinal cord neuromodulation as a therapeutic approach for neuropathic pain.

Pediatric ultrasound practice in Italy: an exploratory survey

BackgroundThe aim of this exploratory survey is to describe the current state of US (ultrasound) technique across different pediatric settings nationwide.MethodsA questionnaire was emailed to all members of the Italian Society of Pediatrics, including pediatric residents. The survey was open from December 2021 to March 2022.ResultsThere were 1098 respondents. Seven hundred and seven pediatricians (84.1%) reported any use of US, while 51 (44.3%) residents denied it. The majority of participants (n = 956, 87.1%) reported to have a US machine available within the department, mostly cart-based (n = 516, 66.9%) and provided from 1 to 5 years prior to the survey (n = 330, 42.8%). Lung and neonatal cerebral regions were the most frequently scanned (n = 289, 18.7% and n = 218, 14.1%, respectively). The suspicion of pneumonia or respiratory distress represented the main reasons for performing US in emergency room (n = 390, 78% and n = 330, 66%, respectively). The majority of family pediatricians reported to scan lung and kidney/urinary tract regions (n = 30, 16.9%, and n = 23,12.9%, respectively). Regarding US training, the majority of respondents (n = 358, 34.6%) declared an experience-based education, with a deficient certification enabling the use of US in 71.6% (n = 552) of cases. The most common barriers included the lack of a well-defined training program (n = 627, 57.1%), unavailability of the US machine (n = 196, 17.9%) and legal responsibility concern (n = 175, 15.9%).ConclusionsDespite the growing interest on pediatric US nationally, significant barriers still limit widespread adoption. These obstacles may be addressed through the dissemination of a specific US education plan and providing additional resources.

Cerebellar gray matter and white matter damage among older adults with prediabetes

AimsTo investigate alterations in cerebrum and cerebellum in prediabetes. Cerebellar injury in diabetes is traceable, but it has not been systematically studied, and whether cerebellar injury occurs and the degree of damage in prediabetes are not known. MethodsThe current study investigated cerebral and cerebellar gray matter volume, white matter volume, white matter microstructure and white matter hyperintensity on T1-weighted, T2-weighted fluid-attenuated inversion recovery and diffusion tensor imaging scans in 78 individuals with normal glucose metabolism, 92 with prediabetes, and 108 with type 2 diabetes. ResultsParticipants with prediabetes showed significant gray matter and white matter atrophy, microstructural damage in the cerebellar and cerebral regions. Additionally, widespread structural alterations were observed in the diabetic stage. The function of the damaged brain area was further decoded in Neurosynth, and the damaged cerebellar area with prediabetic lesions was closely related to motor function, while the area affected by diabetes was related to complex cognitive function in addition to motor function. ConclusionsCerebellar injury had already appeared in the prediabetic stage, and cerebellar injury was aggravated in the diabetic stage; therefore, the cerebellum is a key area that is damaged early in the development of diabetes.

Construction and Application of Cerebral Functional Region-Based Cerebral Blood Flow Atlas Using Magnetic Resonance Imaging-Arterial Spin Labeling.

Cerebral conditions often require precise diagnosis and monitoring, necessitating advanced imaging techniques. Current modalities may not adequately detect early signs of reversible tissue damage, underlining the need for innovative diagnostic tools that can quantify changes in cerebral blood flow (CBF) with high specificity and sensitivity.This study integrates three-dimensional arterial spin labeling (3D-ASL) with structural MRI to develop comprehensive CBF atlases that cover all main functional regions of the brain. This innovative magnetic resonance imaging- arterial spin labeling (MRI-ASL) methodology provides a rapid and noninvasive means of quantifying region-specific CBF, offering a detailed view of CBF levels across different functional regions.The comparison between chronic cerebral ischemia (CCI) patients and healthy subjects revealed significantly diminished CBF across the cerebral functional regions in the constructed CBF atlases for the former. This approach not only allows for the efficient identification of CCI by analyzing concurrent decreases in CBF across critical areas relative to healthy distributions but also enables the tracking of treatment responses and rehabilitation progress through longitudinal CBF atlases.The CBF atlas developed using the MRI-ASL technique represents a novel advancement in the field of cerebral diagnostics and patient care. By comparing regional CBF levels against normative standards, this method enhances diagnostic capabilities, enabling clinicians to provide personalized care to patients with cerebral conditions.

Motor imagery-based brain–computer interface rehabilitation programs enhance upper extremity performance and cortical activation in stroke patients

BackgroundThe most challenging aspect of rehabilitation is the repurposing of residual functional plasticity in stroke patients. To achieve this, numerous plasticity-based clinical rehabilitation programs have been developed. This study aimed to investigate the effects of motor imagery (MI)-based brain–computer interface (BCI) rehabilitation programs on upper extremity hand function in patients with chronic hemiplegia.DesignA 2010 Consolidated Standards for Test Reports (CONSORT)-compliant randomized controlled trial.MethodsForty-six eligible stroke patients with upper limb motor dysfunction participated in the study, six of whom dropped out. The patients were randomly divided into a BCI group and a control group. The BCI group received BCI therapy and conventional rehabilitation therapy, while the control group received conventional rehabilitation only. The Fugl–Meyer Assessment of the Upper Extremity (FMA-UE) score was used as the primary outcome to evaluate upper extremity motor function. Additionally, functional magnetic resonance imaging (fMRI) scans were performed on all patients before and after treatment, in both the resting and task states. We measured the amplitude of low-frequency fluctuation (ALFF), regional homogeneity (ReHo), z conversion of ALFF (zALFF), and z conversion of ReHo (ReHo) in the resting state. The task state was divided into four tasks: left-hand grasping, right-hand grasping, imagining left-hand grasping, and imagining right-hand grasping. Finally, meaningful differences were assessed using correlation analysis of the clinical assessments and functional measures.ResultsA total of 40 patients completed the study, 20 in the BCI group and 20 in the control group. Task-related blood-oxygen-level-dependent (BOLD) analysis showed that when performing the motor grasping task with the affected hand, the BCI group exhibited significant activation in the ipsilateral middle cingulate gyrus, precuneus, inferior parietal gyrus, postcentral gyrus, middle frontal gyrus, superior temporal gyrus, and contralateral middle cingulate gyrus. When imagining a grasping task with the affected hand, the BCI group exhibited greater activation in the ipsilateral superior frontal gyrus (medial) and middle frontal gyrus after treatment. However, the activation of the contralateral superior frontal gyrus decreased in the BCI group relative to the control group. Resting-state fMRI revealed increased zALFF in multiple cerebral regions, including the contralateral precentral gyrus and calcarine and the ipsilateral middle occipital gyrus and cuneus, and decreased zALFF in the ipsilateral superior temporal gyrus in the BCI group relative to the control group. Increased zReHo in the ipsilateral cuneus and contralateral calcarine and decreased zReHo in the contralateral middle temporal gyrus, temporal pole, and superior temporal gyrus were observed post-intervention. According to the subsequent correlation analysis, the increase in the FMA-UE score showed a positive correlation with the mean zALFF of the contralateral precentral gyrus (r = 0.425, P < 0.05), the mean zReHo of the right cuneus (r = 0.399, P < 0.05).ConclusionIn conclusion, BCI therapy is effective and safe for arm rehabilitation after severe poststroke hemiparesis. The correlation of the zALFF of the contralateral precentral gyrus and the zReHo of the ipsilateral cuneus with motor improvements suggested that these values can be used as prognostic measures for BCI-based stroke rehabilitation. We found that motor function was related to visual and spatial processing, suggesting potential avenues for refining treatment strategies for stroke patients.Trial registration: The trial is registered in the Chinese Clinical Trial Registry (number ChiCTR2000034848, registered July 21, 2020).

Wernicke Encephalopathy Caused by Avoidance-Restrictive Food Intake Disorder in a Child: A Case-Based Review.

Wernicke encephalopathy (WE) is an acute and potentially fatal neuropsychiatric disorder resulting from thiamine deficiency: its etiology and clinical presentation can be heterogeneous and arduously recognized, especially in children and adolescents. An 8-year-old girl arrived to the emergency room with ataxic gait, nystagmus, and mental confusion after a 10-day history of repeated severe vomiting; her recent clinical history was characterized by restricted nutrition due to a choking phobia, which caused substantial weight loss. Brain magnetic resonance imaging revealed a bilaterally increased T2 signal in the medial areas of the thalami and cerebral periaqueductal region. Diagnosis of WE based on clinical and neuroradiological findings was established and confirmed after labwork showing low serum thiamine. Following psychiatric evaluation, the patient was also diagnosed with avoidance-restrictive food intake disorder (ARFID), which required starting cognitive behavioral therapy and introducing aripiprazole. The patient displayed improvement of the radiological findings after one month and complete resolution of her neurological symptoms and signs. Eating disorders like ARFID might forerun acute signs of WE; this possibility should be considered even in pediatric patients, especially when atypical neurological pictures or feeding issues come out.

Effects of Paradoxical Sleep Deprivation on MCH and Hypocretin Systems

AbstractMelanin-concentrating hormone (MCH) and hypocretins (Hcrt) 1 and 2 are neuropeptides synthesized in the lateral hypothalamic area by neurons that are critical in the regulation of sleep and wakefulness. Their receptors are located in the same cerebral regions, including the frontal cortex and hippocampus. The present study aimed to assess whether 96 hours of paradoxical sleep deprivation alters the functioning of the MCH and hypocretin systems. To do this, in control rats with normal sleep (CTL) and in rats that were deprived of paradoxical sleep (SD), we quantified the following parameters: 1) levels of MCH and hypocretin-1 in the cerebrospinal fluid (CSF); 2) expression of the prepro-MCH (Pmch) and prepro-hypocretin (Hcrt) genes in the hypothalamus; 3) expression of the Mchr1 and Hcrtr1 genes in the frontal cortex and hippocampus; and 4) expression of the Hcrtr2 gene in the hippocampus. These measures were performed at 6 Zeitgeber time (ZT) points of the day (ZTs: 0, 4, 8, 12, 16, and 20). In the SD group, we found higher levels of MCH in the CSF at the beginning of the dark phase. In the frontal cortex, sleep deprivation decreased the expression of Hcrtr1 at ZT0. Moreover, we identified significant differences between the light and dark phases in the expression of Mchr1 and Hcrtr1, but only in the CTL animals. We conclude that there is a day/night modulation in the expression of components of the MCH and hypocretin systems, and this profile is affected by paradoxical sleep deprivation.

Simultaneous MEG and EEG source imaging of electrophysiological activity in response to acute transcranial photobiomodulation.

Transcranial photobiomodulation (tPBM) is a non-invasive neuromodulation technique that improves human cognition. The effects of tPBM of the right forehead on neurophysiological activity have been previously investigated using EEG in sensor space. However, the spatial resolution of these studies is limited. Magnetoencephalography (MEG) is known to facilitate a higher spatial resolution of brain source images. This study aimed to image post-tPBM effects in brain space based on both MEG and EEG measurements across the entire human brain. MEG and EEG scans were concurrently acquired for 6 min before and after 8-min of tPBM delivered using a 1,064-nm laser on the right forehead of 25 healthy participants. Group-level changes in both the MEG and EEG power spectral density with respect to the baseline (pre-tPBM) were quantified and averaged within each frequency band in the sensor space. Constrained modeling was used to generate MEG and EEG source images of post-tPBM, followed by cluster-based permutation analysis for family wise error correction (p < 0.05). The 8-min tPBM enabled significant increases in alpha (8-12 Hz) and beta (13-30 Hz) powers across multiple cortical regions, as confirmed by MEG and EEG source images. Moreover, tPBM-enhanced oscillations in the beta band were located not only near the stimulation site but also in remote cerebral regions, including the frontal, parietal, and occipital regions, particularly on the ipsilateral side. MEG and EEG results shown in this study demonstrated that tPBM modulates neurophysiological activity locally and in distant cortical areas. The EEG topographies reported in this study were consistent with previous observations. This study is the first to present MEG and EEG evidence of the electrophysiological effects of tPBM in the brain space, supporting the potential utility of tPBM in treating neurological diseases through the modulation of brain oscillations.

Evaluation of the Therapeutical Effect of Matricaria Chamomilla Extract vs. Galantamine on Animal Model Memory and Behavior Using 18F-FDG PET/MRI.

The memory-enhancing activity of Matricaria chamomilla hydroalcoholic extract (MCE) is already being investigated by behavioral and biochemical assays in scopolamine-induced amnesia rat models, while the effects of scopolamine (Sco) on cerebral glucose metabolism are examined as well. Nevertheless, the study of the metabolic profile determined by an enriched MCE has not been performed before. The present experiments compared metabolic quantification in characteristic cerebral regions and behavioral characteristics for normal, only diseased, diseased, and MCE- vs. Galantamine (Gal)-treated Wistar rats. A memory deficit was induced by four weeks of daily intraperitoneal Sco injection. Starting on the eighth day, the treatment was intraperitoneally administered 30 min after Sco injection for a period of three weeks. The memory assessment comprised three maze tests. Glucose metabolism was quantified after the 18F-FDG PET examination. The right amygdala, piriform, and entorhinal cortex showed the highest differential radiopharmaceutical uptake of the 50 regions analyzed. Rats treated with MCE show metabolic similarity with normal rats, while the Gal-treated group shows features closer to the diseased group. Behavioral assessments evidenced a less anxious status and a better locomotor activity manifested by the MCE-treated group compared to the Gal-treated group. These findings prove evident metabolic ameliorative qualities of MCE over Gal classic treatment, suggesting that the extract could be a potent neuropharmacological agent against amnesia.

Selective bioaccumulation of polystyrene nanoplastics in fetal rat brain and damage to myelin development

Micro(nano)plastic, as a new type of environmental pollutant, have become a potential threat to the life and health of various stages of biology. However, it is not yet clear whether they will affect brain development in the fetal stage. Therefore, this study aims to explore the potential effects of nanoplastics on the development of fetal rat brains. To assess the allocation of NPs (25 nm and 50 nm) in various regions of the fetal brain, pregnant rats were exposed to concentrations (50, 10, 2.5, and 0.5 mg/kg) of PS-NPs. Our results provided evidence of the transplacental transfer of PS-NPs to the fetal brain, with a prominent presence observed in several cerebral regions, notably the cerebellum, hippocampus, striatum, and prefrontal cortex. This distribution bias might be linked to the developmental sequence of each brain region. Additionally, we explored the influence of prenatal exposure on the myelin development of the cerebellum, given its the highest PS-NP accumulation in offspring. Compared with control rats, PS-NPs exposure caused a significant reduction in myelin basic protein (MBP) and myelin oligodendrocyte glycoprotein (MOG) expression, a decrease in myelin thickness, an increase in cell apoptosis, and a decline in the oligodendrocyte population. These effects gave rise to motor deficits. In conclusion, our results identified the specific distribution of NPs in the fetal brain following prenatal exposure and revealed that prenatal exposure to PS-NPs can suppress myelin formation in the cerebellum of the fetus.

Spiral time-of-flight magnetic resonance angiography for intracranial vascular imaging: performance compared to conventional Cartesian angiogram.

Computed tomography angiography (CTA) and digital subtraction angiography (DSA) usually raise the risk of potential malignancies with cumulative radiation doses. Current time-of-flight magnetic resonance angiography (TOF-MRA) (dubbed as cTOF), which is based on Cartesian sampling mode, may show limited diagnostic conspicuity at sinuous or branching regions. It is also prone to relatively high false positive diagnoses and undesirable display of distal intracranial vessels. This study aimed to use spiral TOF-MRA (sTOF) as a noninvasive alternative to explore possible improvement, such that the application of magnetic resonance angiography (MRA) can be extended to facilitate clinical examination or cerebrovascular disease diagnosis and follow-up studies. Initially, 37 patients with symptoms of dizziness or transient ischemic attack were consecutively recruited for suspected intracranial vascular disease examination from Zhongshan Hospital of Xiamen University between July 2020 and April 2021 in this cross-sectional prospective study. After excluding 1 patient with severe scanning artifacts, 1 patient whose scanning scope did not meet the requirement, and 1 patient with confounding tumor lesions, a total of 34 participants were included according to the inclusion and exclusion criteria. Each participant underwent intracranial vascular imaging with both sTOF and cTOF sequences on a 3.0 T MR scanner with a conventional head-neck coil of 16 channels. Contrast CTA or DSA was also performed for 15 patients showing pathology. Qualitative comparisons in terms of image quality and diagnostic efficacy ratings, quantitative comparisons in terms of signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), vessel length, and sharpness were evaluated. Pair-wise Wilcoxon test was performed to evaluate the imaging quality derived from cTOF and sTOF acquisitions and weighted Cohen's Kappa was conducted to assess the rating consistency between different physicians. Compared to cTOF, sTOF showed better performance with fewer artifacts. It can effectively alleviate false positives of normal vessels being misdiagnosed as aneurysm or stenosis. Improved conspicuity was observed in cerebral distal regions with more clearly identifiable vasculature at finer scales. Quantitative comparisons in selected regions revealed significant improvement of sTOF in SNR (P<0.01 or P<0.001), CNR (P<0.001), vessel length (P<0.001), and sharpness (P<0.001) as compared to cTOF. Besides, sTOF can depict details of M1 and M2 segments of middle cerebral artery (MCA) at metallic implant region, showing its resistance to magnetic susceptibility. The sTOF shows higher imaging quality and lesion detectability with reduced artifacts and false positives, representing a potentially feasible surrogate in intracranial vascular imaging for future clinic routines.