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1.
Braz. J. Psychiatry (São Paulo, 1999, Impr.) ; 42(1): 6-13, Jan.-Feb. 2020. tab, graf
Article in English | LILACS | ID: biblio-1055355

ABSTRACT

Objective: To test the feasibility and to present preliminary results of a neuroimaging protocol to evaluate adolescent depression in a middle-income setting. Methods: We assessed psychotropic medication-free adolescents (age range 14-16 years) with a diagnosis of major depressive disorder (MDD). Participants underwent a comprehensive clinical evaluation and both structural and functional magnetic resonance imaging (fMRI). In this pilot study, a preliminary single-group analysis of resting-state fMRI (rs-fMRI) data was performed, with a focus on the default mode network (DMN), cognitive control network (CCN), and salience network (SN). Results: The sample included 29 adolescents with MDD (mean age 16.01, SD 0.78) who completed the protocol. Only two participants were excluded due to MRI quality issues (head movement), and were not included in the analyses. The scans showed significant connectivity between the medial prefrontal cortex and posterior cingulate cortex (DMN), the ACC and anterior insula (SN), and the lateral prefrontal cortex and dorsal parietal cortex (CCN). Conclusion: We demonstrated the feasibility of implementing a complex neuroimaging protocol in a middle-income country. Further, our preliminary rs-fMRI data revealed patterns of resting-state connectivity consistent with prior research performed in adolescents from high-income countries.


Subject(s)
Humans , Male , Adolescent , Magnetic Resonance Imaging/methods , Depressive Disorder, Major/diagnostic imaging , Neuroimaging/methods , Quality Control , Socioeconomic Factors , Brazil , Cerebral Cortex/diagnostic imaging , Feasibility Studies , Surveys and Questionnaires , Reproducibility of Results , Depressive Disorder, Major/physiopathology , Neural Pathways , Neuropsychological Tests
3.
Article in Chinese | WPRIM | ID: wpr-828872

ABSTRACT

OBJECTIVE@#To investigate the potential neural pathway connecting the nucleus accumbens (NAc) and the rostral ventrolateral medulla (RVLM), and whether the pathway participates in the regulation of cardiovascular function in a model rat of anorexia nervosa (AN).@*METHODS@#Rat models of AN were established by allowing voluntary activity in a running wheel with restricted feeding, with the rats having free access to normal chow without exercise as the control group. FluoroGold (FG) retrograde tracing method and multi-channel simultaneous recording technique were used to explore the possible pathway between the NAc and the RVLM.@*RESULTS@#The rats in AN group exhibited significantly reduced systolic blood pressure (SBP), mean arterial pressure (MAP) and heart rate (HR) with significantly increased discharge frequency of RVLM neurons in comparison with the control rats. After the injection of FG into the RVLM, retrograde labeled neurons were observed in the NAc of the rats in both the normal control and AN groups. In both groups, SBP and HR were significantly decreased in response to 400 μA electrical stimulation of the NAc accompanied by an obvious increase in the discharge frequency of the RVLM neurons; the diastolic blood pressure (DBP) and MAP were significantly lower in AN model rats than in the normal rats in response to the stimulation.@*CONCLUSIONS@#We successfully established a rat model of AN via hyperactivity and restricted feeding and confirm the presence of a neural pathway connecting the NAc and the RVLM. This pathway might participate in the regulation of cardiovascular function in AN model rats.


Subject(s)
Animals , Anorexia Nervosa , Blood Pressure , Disease Models, Animal , Medulla Oblongata , Neural Pathways , Nucleus Accumbens , Rats , Rats, Sprague-Dawley
4.
Arq. neuropsiquiatr ; 77(9): 672-674, Sept. 2019. graf
Article in English | LILACS | ID: biblio-1038749

ABSTRACT

ABSTRACT Alice in Wonderland syndrome (AIWS) is a paroxysmal, perceptual, visual and somesthetic disorder that can be found in patients with migraine, epilepsy, cerebrovascular disease or infections. The condition is relatively rare and unique in its hallucinatory characteristics. Objective: To discuss the potential pathways involved in AIWS. Interest in this subject arose from a patient seen at our service, in which dysmetropsia of body image was reported by the patient, when she saw it in her son. Methods: We reviewed and discussed the medical literature on reported patients with AIWS, possible anatomical pathways involved and functional imaging studies. Results: A complex neural network including the right temporoparietal junction, secondary somatosensory cortex, premotor cortex, right posterior insula, and primary and extrastriate visual cortical regions seem to be involved in AIWS to varying degrees. Conclusions: AIWS is a very complex condition that typically has been described as isolated cases or series of cases.


RESUMO Síndrome de Alice no País das Maravilhas (SAPM) é uma condição paroxística visual perceptiva e somestésica que pode ser encontrada em pacientes com enxaqueca, epilepsia, doença cerebrovascular ou infecções. A condição é relativamente rara e tem características alucinatórias peculiares. Objetivo: Discutir as potenciais vias envolvidas na SAPM. O interesse pelo assunto surgiu com um caso de nosso serviço, onde a distropsia da imagem corporal foi relatada pela paciente, que via isto em seu filho. Métodos: Os autores revisaram e discutiram a literatura médica de casos relatados de SAPM, possíveis vias anatômicas envolvidas e estudos de imagem funcional. Resultados: Uma complexa rede neural incluindo junção temporoparietal direita, córtex somatossensitivo secundário, córtex pré-motor, região posterior da ínsula direita, e regiões do córtex visual primário e extra-estriatal têm diferentes graus de envolvimento na SAPM. Conclusão: SAPM é uma condição complexa que tipicamente foi descrita apenas com casos isolados ou séries de casos.


Subject(s)
Humans , Female , Aged, 80 and over , Alice in Wonderland Syndrome/pathology , Alice in Wonderland Syndrome/diagnostic imaging , Hallucinations/pathology , Hallucinations/diagnostic imaging , Magnetic Resonance Imaging , Neuroimaging/methods , Headache/pathology , Headache/diagnostic imaging , Neural Pathways
5.
Rev. chil. cir ; 71(1): 15-21, feb. 2019. tab, ilus
Article in Spanish | LILACS | ID: biblio-985373

ABSTRACT

Resumen Introducción: Conocer en detalle la inervación interna del músculo temporal humano permite realizar múltiples técnicas quirúrgicas y tratamientos de patologías que involucran al territorio craneofacial. Si bien en la literatura se ha descrito la inervación interna del músculo temporal humano basado en micro-disección directa, la técnica de tinción de Sihler es una herramienta ventajosa para el estudio anatómico ya que permite observar ramos nerviosos pequeños sin perder su relación tridimensional con las fibras musculares. Objetivo: Describir la distribución nerviosa al interior del músculo temporal humano en cadáveres al aplicar el método de Sihler y analizar su asociación anátomo quirúrgica. Materiales y Método: Ocho músculos temporales humanos previamente disecados fueron sometidos al método de tinción de Sihler. Cada una de las muestras se observó bajo lupa estereoscópica y transiluminación; finalmente para su descripción se dividió al músculo en tres regiones. Resultados: Se determinó la presencia de tres troncos nerviosos principales: el temporal profundo anterior, el temporal profundo medio y temporal profundo posterior, los que discurren de profundo a superficial. Además, se observaron ramos colaterales de menor calibre del nervio temporal profundo posterior que en forma de arco comunican las tres regiones del músculo. Conclusión: Se describió una distribución nerviosa interna común para los músculos estudiados en las tres dimensiones del espacio, conocimiento útil para innovar en terapias clínico-quirúrgicas del territorio craneofacial.


Introduction: Knowing in detail the inner innervation of the human temporal muscle allows to perform multiple surgical techniques and treatments of pathologies that involve the craniofacial territory. Although the internal innervation of the human temporal muscle based on direct microdissection has been described in the literature, the Sihler staining technique is an advantageous tool for anatomical study since it allows observing small nerve branches without losing its three-dimensional relationship with muscle fibers. Aim: To describe the nervous distribution within the human temporal muscle in cadavers by applying the Sihler method and analyzing its surgical anatomical association. Materials and Method: Eight previously dissected human temporal muscles were subjected to the Sihler staining method. Each one of the samples was observed under stereoscopic magnification and transillumination, finally for its description the muscle was divided into three regions. Results: The presence of three main nervous trunks was determined: the anterior deep temporal, the deep medium temporal and the posterior deep temporal, those that run from deep to superficial. In addition, collateral branches of lesser caliber of the posterior deep temporal nerve that in the form of an arc communicate the three regions of the muscle were observed. Conclusion: A common internal nervous distribution was described for the muscles studied in the three dimensions of space, useful knowledge to innovate in clinical-surgical therapies of the craniofacial territory.


Subject(s)
Humans , Temporal Muscle/physiopathology , Temporal Muscle/diagnostic imaging , Nerve Net , Temporal Muscle/surgery , Craniofacial Abnormalities/pathology , Neural Pathways
6.
Neuroscience Bulletin ; (6): 369-377, 2019.
Article in English | WPRIM | ID: wpr-775470

ABSTRACT

Immediate-early genes (IEGs) have long been used to visualize neural activations induced by sensory and behavioral stimuli. Recent advances in imaging techniques have made it possible to use endogenous IEG signals to visualize and discriminate neural ensembles activated by multiple stimuli, and to map whole-brain-scale neural activation at single-neuron resolution. In addition, a collection of IEG-dependent molecular tools has been developed that can be used to complement the labeling of endogenous IEG genes and, especially, to manipulate activated neural ensembles in order to reveal the circuits and mechanisms underlying different behaviors. Here, we review these techniques and tools in terms of their utility in studying functional neural circuits. In addition, we provide an experimental strategy to measure the signal-to-noise ratio of IEG-dependent molecular tools, for evaluating their suitability for investigating relevant circuits and behaviors.


Subject(s)
Animals , Brain , Metabolism , Gene Expression Profiling , Methods , Genes, Immediate-Early , Humans , Molecular Imaging , Methods , Neural Pathways , Metabolism , Neurons , Metabolism , Signal-To-Noise Ratio
7.
Neuroscience Bulletin ; (6): 315-324, 2019.
Article in English | WPRIM | ID: wpr-775449

ABSTRACT

The thalamostriatal pathway is implicated in Parkinson's disease (PD); however, PD-related changes in the relationship between oscillatory activity in the centromedian-parafascicular complex (CM/Pf, or the Pf in rodents) and the dorsal striatum (DS) remain unclear. Therefore, we simultaneously recorded local field potentials (LFPs) in both the Pf and DS of hemiparkinsonian and control rats during epochs of rest or treadmill walking. The dopamine-lesioned rats showed increased LFP power in the beta band (12 Hz-35 Hz) in the Pf and DS during both epochs, but decreased LFP power in the delta (0.5 Hz-3 Hz) band in the Pf during rest epochs and in the DS during both epochs, compared to control rats. In addition, exaggerated low gamma (35 Hz-70 Hz) oscillations after dopamine loss were restricted to the Pf regardless of the behavioral state. Furthermore, enhanced synchronization of LFP oscillations was found between the Pf and DS after the dopamine lesion. Significant increases occurred in the mean coherence in both theta (3 Hz-7 Hz) and beta bands, and a significant increase was also noted in the phase coherence in the beta band between the Pf and DS during rest epochs. During the treadmill walking epochs, significant increases were found in both the alpha (7 Hz-12 Hz) and beta bands for two coherence measures. Collectively, dramatic changes in the relative LFP power and coherence in the thalamostriatal pathway may underlie the dysfunction of the basal ganglia-thalamocortical network circuits in PD, contributing to some of the motor and non-motor symptoms of the disease.


Subject(s)
Animals , Brain Waves , Physiology , Corpus Striatum , Cortical Synchronization , Physiology , Dopaminergic Neurons , Physiology , Electrocorticography , Male , Neural Pathways , Oxidopamine , Parkinsonian Disorders , Rats, Wistar , Thalamic Nuclei , Walking , Physiology
8.
Neuroscience Bulletin ; (6): 447-460, 2019.
Article in English | WPRIM | ID: wpr-775438

ABSTRACT

A deficit in spatial memory has been taken as an early predictor of Alzheimer's disease (AD) or mild cognitive impairment (MCI). The uncinate fasciculus (UF) is a long-range white-matter tract that connects the anterior temporal lobe with the orbitofrontal cortex (OFC) in primates. Previous studies have shown that the UF impairment associated with spatial memory deficits may be an important pathological change in aging and AD, but its exact role in spatial memory is not well understood. The pathway arising from the postrhinal cortex (POR) and projecting to the ventrolateral orbitofrontal cortex (vlOFC) performs most of the functions of the UF in rodents. Although the literature suggests an association between spatial memory and the regions connected by the POR-vlOFC pathway, the function of the pathway in spatial memory is relatively unknown. To further illuminate the function of the UF in spatial memory, we dissected the POR-vlOFC pathway in mice. We determined that the POR-vlOFC pathway is a glutamatergic structure, and that glutamatergic neurons in the POR regulate spatial memory retrieval. We also demonstrated that the POR-vlOFC pathway specifically transmits spatial information to participate in memory retrieval. These findings provide a deeper understanding of UF function and dysfunction related to disorders of memory, as in MCI and AD.


Subject(s)
Animals , Glutamic Acid , Physiology , Male , Mental Recall , Physiology , Mice, Inbred C57BL , Neural Pathways , Cell Biology , Physiology , Neuroanatomical Tract-Tracing Techniques , Neurons , Physiology , Prefrontal Cortex , Cell Biology , Physiology , Spatial Memory , Physiology , Temporal Lobe , Cell Biology , Physiology
9.
Article in English | WPRIM | ID: wpr-765951

ABSTRACT

BACKGROUND/AIMS: Fecal incontinence (FI) is a prevalent condition among women. While biomechanical motor components have been thoroughly researched, anorectal sensory aspects are less known. We studied the pathophysiology of FI in community-dwelling women, specifically, the conduction through efferent/afferent neural pathways. METHODS: A cross-sectional study was conducted on 175 women with FI and 19 healthy volunteers. The functional/structural study included anorectal manometry/endoanal ultrasound. Neurophysiological studies including pudendal nerve terminal motor latency (PNTML) and sensory-evoked-potentials to anal/rectal stimulation (ASEP/RSEP) were conducted on all healthy volunteers and on 2 subgroups of 42 and 38 patients, respectively. RESULTS: The main conditions associated with FI were childbirth (79.00%) and coloproctological surgery (37.10%). Cleveland score was 11.39 ± 4.09. Anorectal manometry showed external anal sphincter and internal anal sphincter insufficiency in 82.85% and 44.00%, respectively. Sensitivity to rectal distension was impaired in 27.42%. Endoanal ultrasound showed tears in external anal sphincter (60.57%) and internal anal sphincter disruptions (34.80%). Abnormal anorectal sensory conduction was evidenced through ASEP and RSEP in 63.16% and 50.00% of patients, respectively, alongside reduced activation of brain cortex to anorectal stimulation. In contrast, PNTML was delayed in only 33.30%. Stools were loose/very loose in 56.70% of patients. CONCLUSIONS: Pathophysiology of FI in women is mainly associated with mechanical sphincter dysfunctions related to either muscle damage or, to a lesser extent, impaired efferent conduction at pudendal nerves. Impaired conduction through afferent anorectal pathways is also very prevalent in women with FI and may play an important role as a pathophysiological factor and as a potential therapeutic target.


Subject(s)
Anal Canal , Brain , Cross-Sectional Studies , Evoked Potentials , Fecal Incontinence , Female , Healthy Volunteers , Humans , Manometry , Neural Pathways , Parturition , Pudendal Nerve , Tears , Ultrasonography
10.
Braz. j. med. biol. res ; 52(5): e8244, 2019. tab, graf
Article in English | LILACS | ID: biblio-1001520

ABSTRACT

This study aimed to explore the structural and functional characteristics of the neural network of resting-state brain activities in patients with amnestic mild cognitive impairment (aMCI) by functional magnetic resonance imaging (fMRI) technology. Resting state fMRI scanning was performed on 10 clinically diagnosed aMCI patients and 10 healthy volunteers, and the difference in the resting-state brain activities between aMCI patients and healthy volunteers was compared using the brain function network regional homogeneity (ReHo) analysis method. Results of the ReHo analysis of aMCI patients and healthy volunteers revealed that the ReHo value significantly increased in the posterior cingulate gyrus region, medial frontal lobe, medial cortex of the prefrontal lobe, and part of the parietal lobe. Compared with the normal elderlies, ReHo decreased in aMCI patients in the left temporal lobe (middle temporal gyrus and inferior temporal gyrus), left parahippocampal gyrus, occipital lobe, lingual gyrus, precuneus, and other regions while ReHo increased in regions of the right frontal lobe (inferior frontal gyrus), left superior temporal gyrus, precentral gyrus (frontal lobe), right thalamus, left fusiform gyrus, and other regions. In the resting state, there may be regional abnormalities in brain functional areas in aMCI patients, which may be associated with cognitive impairment.


Subject(s)
Humans , Male , Female , Middle Aged , Aged , Brain/physiology , Cognitive Dysfunction/physiopathology , Image Processing, Computer-Assisted , Brain/diagnostic imaging , Brain Mapping , Magnetic Resonance Imaging , Cognitive Dysfunction/diagnostic imaging , Neural Pathways/physiopathology
11.
Neuroscience Bulletin ; (6): 647-658, 2018.
Article in English | WPRIM | ID: wpr-775510

ABSTRACT

A number of studies have indicated that disorders of consciousness result from multifocal injuries as well as from the impaired functional and anatomical connectivity between various anterior forebrain regions. However, the specific causal mechanism linking these regions remains unclear. In this study, we used spectral dynamic causal modeling to assess how the effective connections (ECs) between various regions differ between individuals. Next, we used connectome-based predictive modeling to evaluate the performance of the ECs in predicting the clinical scores of DOC patients. We found increased ECs from the striatum to the globus pallidus as well as from the globus pallidus to the posterior cingulate cortex, and decreased ECs from the globus pallidus to the thalamus and from the medial prefrontal cortex to the striatum in DOC patients as compared to healthy controls. Prediction of the patients' outcome was effective using the negative ECs as features. In summary, the present study highlights a key role of the thalamo-basal ganglia-cortical loop in DOCs and supports the anterior forebrain mesocircuit hypothesis. Furthermore, EC could be potentially used to assess the consciousness level.


Subject(s)
Adult , Bayes Theorem , Connectome , Consciousness Disorders , Diagnostic Imaging , Female , Humans , Machine Learning , Magnetic Resonance Imaging , Male , Middle Aged , Neural Pathways , Diagnostic Imaging , Prognosis , Prosencephalon , Diagnostic Imaging , Young Adult
12.
Neuroscience Bulletin ; (6): 921-938, 2018.
Article in English | WPRIM | ID: wpr-775495

ABSTRACT

Neurostimulation remarkably alleviates the symptoms in a variety of brain disorders by modulating the brain-wide network. However, how brain-wide effects on the direct and indirect pathways evoked by focal neurostimulation elicit therapeutic effects in an individual patient is unknown. Understanding this remains crucial for advancing neural circuit-based guidance to optimize candidate patient screening, pre-surgical target selection, and post-surgical parameter tuning. To address this issue, we propose a functional brain connectome-based modeling approach that simulates the spreading effects of stimulating different brain regions and quantifies the rectification of abnormal network topology in silico. We validated these analyses by pinpointing nuclei in the basal ganglia circuits as top-ranked targets for 43 local patients with Parkinson's disease and 90 patients from a public database. Individual connectome-based analysis demonstrated that the globus pallidus was the best choice for 21.1% and the subthalamic nucleus for 19.5% of patients. Down-regulation of functional connectivity (up to 12%) at these prioritized targets optimally maximized the therapeutic effects. Notably, the priority rank of the subthalamic nucleus significantly correlated with motor symptom severity (Unified Parkinson's Disease Rating Scale III) in the local cohort. These findings underscore the potential of neural network modeling for advancing personalized brain stimulation therapy, and warrant future experimental investigation to validate its clinical utility.


Subject(s)
Adult , Aged , Brain Mapping , Connectome , Deep Brain Stimulation , Methods , Female , Humans , Image Processing, Computer-Assisted , Magnetic Resonance Imaging , Male , Middle Aged , Neural Pathways , Diagnostic Imaging , Physiology , Oxygen , Blood , Parkinson Disease , Diagnostic Imaging , Pathology , Therapeutics , ROC Curve , United Kingdom
13.
Neuroscience Bulletin ; (6): 715-724, 2018.
Article in English | WPRIM | ID: wpr-775494

ABSTRACT

Stroke at the acute stage is a major cause of disability in adults, and is associated with dysfunction of brain networks. However, the mechanisms underlying changes in brain connectivity in stroke are far from fully elucidated. In the present study, we investigated brain metabolism and metabolic connectivity in a rat ischemic stroke model of middle cerebral artery occlusion (MCAO) at the acute stage using F-fluorodeoxyglucose positron emission tomography. Voxel-wise analysis showed decreased metabolism mainly in the ipsilesional hemisphere, and increased metabolism mainly in the contralesional cerebellum. We used further metabolic connectivity analysis to explore the brain metabolic network in MCAO. Compared to sham controls, rats with MCAO showed most significantly reduced nodal and local efficiency in the ipsilesional striatum. In addition, the MCAO group showed decreased metabolic central connection of the ipsilesional striatum with the ipsilesional cerebellum, ipsilesional hippocampus, and bilateral hypothalamus. Taken together, the present study demonstrated abnormal metabolic connectivity in rats at the acute stage of ischemic stroke, which might provide insight into clinical research.


Subject(s)
Acute Disease , Animals , Brain , Diagnostic Imaging , Metabolism , Brain Mapping , Disease Models, Animal , Fluorodeoxyglucose F18 , Glucose , Metabolism , Infarction, Middle Cerebral Artery , Diagnostic Imaging , Metabolism , Male , Neural Pathways , Diagnostic Imaging , Metabolism , Positron-Emission Tomography , Radiopharmaceuticals , Random Allocation , Rats, Sprague-Dawley
14.
Neuroscience Bulletin ; (6): 725-735, 2018.
Article in English | WPRIM | ID: wpr-775493

ABSTRACT

An important and unresolved question is how human brain regions process information and interact with each other in intertemporal choice related to gains and losses. Using psychophysiological interaction and dynamic causal modeling analyses, we investigated the functional interactions between regions involved in the decision-making process while participants performed temporal discounting tasks in both the gains and losses domains. We found two distinct intrinsic valuation systems underlying temporal discounting in the gains and losses domains: gains were specifically evaluated in the medial regions, including the medial prefrontal and orbitofrontal cortices, and losses were evaluated in the lateral dorsolateral prefrontal cortex. In addition, immediate reward or punishment was found to modulate the functional interactions between the dorsolateral prefrontal cortex and distinct regions in both the gains and losses domains: in the gains domain, the mesolimbic regions; in the losses domain, the medial prefrontal cortex, anterior cingulate cortex, and insula. These findings suggest that intertemporal choice of gains and losses might involve distinct valuation systems, and more importantly, separate neural interactions may implement the intertemporal choices of gains and losses. These findings may provide a new biological perspective for understanding the neural mechanisms underlying intertemporal choice of gains and losses.


Subject(s)
Adult , Brain , Diagnostic Imaging , Physiology , Brain Mapping , Delay Discounting , Physiology , Female , Humans , Magnetic Resonance Imaging , Male , Neural Pathways , Diagnostic Imaging , Physiology , Neuropsychological Tests , Psychophysics , Reward , Young Adult
15.
Neuroscience Bulletin ; (6): 1105-1110, 2018.
Article in English | WPRIM | ID: wpr-775478

ABSTRACT

Animals choose among sleep, courtship, and feeding behaviors based on the integration of both external sensory cues and internal states; such choices are essential for survival and reproduction. These competing behaviors are closely related and controlled by distinct neural circuits, but whether they are also regulated by shared neural nodes is unclear. Here, we investigated how a set of male-specific P1 neurons controls sleep, courtship, and feeding behaviors in Drosophila males. We found that mild activation of P1 neurons was sufficient to affect sleep, but not courtship or feeding, while stronger activation of P1 neurons labeled by four out of five independent drivers induced courtship, but only the driver that targeted the largest number of P1 neurons affected feeding. These results reveal a common neural node that affects sleep, courtship, and feeding in a threshold-dependent manner, and provide insights into how competing behaviors can be regulated by a shared neural node.


Subject(s)
Animals , Animals, Genetically Modified , Brain , Cell Biology , Courtship , Drosophila , Drosophila Proteins , Genetics , Metabolism , Feeding Behavior , Physiology , Locomotion , Male , Neural Inhibition , Physiology , Neural Pathways , Physiology , Neurons , Physiology , Sex Factors , Sleep , Physiology
16.
Experimental Neurobiology ; : 94-102, 2018.
Article in English | WPRIM | ID: wpr-714117

ABSTRACT

The hippocampus and olfactory bulb incorporate new neurons migrating from neurogenic regions in the brain. Hippocampal atrophy is evident in numerous neurodegenerative disorders, and altered hippocampal neurogenesis is an early pathological event in Alzheimer's disease. We hypothesized that hippocampal neurogenesis is affected by olfactory stimuli through the neural pathway of olfaction-related memory. In this study, we exposed mice to novel pleasant odors for three weeks and then assessed the number of neurons, non-neuronal cells (mainly glia) and proliferating cells in the hippocampus and olfactory bulb, using the isotropic fractionator method. We found that the odor enrichment significantly increased the neuronal cell numbers in the hippocampus, and promoted cell proliferation and neurogenesis in the olfactory bulb. In contrast, the glial cell numbers remained unchanged in both of the regions. Our results suggest that exposure to novel odor stimuli promotes hippocampal neurogenesis and support the idea that enriched environments may delay the onset or slow down the progression of neurodegenerative disorders.


Subject(s)
Alzheimer Disease , Animals , Atrophy , Brain , Cell Count , Cell Proliferation , Hippocampus , Memory , Methods , Mice , Neural Pathways , Neurodegenerative Diseases , Neurogenesis , Neuroglia , Neurons , Odorants , Olfactory Bulb
17.
Article in English | WPRIM | ID: wpr-714056

ABSTRACT

Hiccups are an involuntary contraction of the diaphragm that may repeat several times per minute. In general, hiccups are very common, transient, and self-limited. However, if the condition persists longer than days or months, it impacts a patient's quality of life. Pharmacologic and non-pharmacologic methods are used for the treatment of persistent or intractable hiccups. Nerve block and stimulation have been shown to be effective through neural pathway interruption or stimulation of the hiccup reflex arc. Stellate ganglion block (SGB) is an injection of local anesthetic adjacent to a group of nerves in the neck known as the stellate ganglion. The authors report a case of SGB as an effective treatment for a patient with intractable hiccups resulting from right lateral medullary syndrome.


Subject(s)
Diaphragm , Hiccup , Humans , Lateral Medullary Syndrome , Neck , Nerve Block , Neural Pathways , Quality of Life , Reflex , Stellate Ganglion , Sympathetic Nervous System
18.
Neuroscience Bulletin ; (6): 438-448, 2018.
Article in English | WPRIM | ID: wpr-777052

ABSTRACT

Diffusion-weighted magnetic resonance imaging (dMRI) is widely used to study white and gray matter (GM) micro-organization and structural connectivity in the brain. Super-resolution track-density imaging (TDI) is an image reconstruction method for dMRI data, which is capable of providing spatial resolution beyond the acquired data, as well as novel and meaningful anatomical contrast that cannot be obtained with conventional reconstruction methods. TDI has been used to reveal anatomical features in human and animal brains. In this study, we used short track TDI (stTDI), a variation of TDI with enhanced contrast for GM structures, to reconstruct direction-encoded color maps of fixed tree shrew brain. The results were compared with those obtained with the traditional diffusion tensor imaging (DTI) method. We demonstrated that fine microstructures in the tree shrew brain, such as Baillarger bands in the primary visual cortex and the longitudinal component of the mossy fibers within the hippocampal CA3 subfield, were observable with stTDI, but not with DTI reconstructions from the same dMRI data. The possible mechanisms underlying the enhanced GM contrast are discussed.


Subject(s)
Animals , Brain Mapping , Diffusion Tensor Imaging , Methods , Hippocampus , Diagnostic Imaging , Image Processing, Computer-Assisted , Methods , Male , Neural Pathways , Diagnostic Imaging , Tupaiidae , Visual Cortex , Diagnostic Imaging
19.
Neuroscience Bulletin ; (6): 485-496, 2018.
Article in English | WPRIM | ID: wpr-777034

ABSTRACT

The GABAergic neurons in the parafacial zone (PZ) play an important role in sleep-wake regulation and have been identified as part of a sleep-promoting center in the brainstem, but the long-range connections mediating this function remain poorly characterized. Here, we performed whole-brain mapping of both the inputs and outputs of the GABAergic neurons in the PZ of the mouse brain. We used the modified rabies virus EnvA-ΔG-DsRed combined with a Cre/loxP gene-expression strategy to map the direct monosynaptic inputs to the GABAergic neurons in the PZ, and found that they receive inputs mainly from the hypothalamic area, zona incerta, and parasubthalamic nucleus in the hypothalamus; the substantia nigra, pars reticulata and deep mesencephalic nucleus in the midbrain; and the intermediate reticular nucleus and medial vestibular nucleus (parvocellular part) in the pons and medulla. We also mapped the axonal projections of the PZ GABAergic neurons with adeno-associated virus, and defined the reciprocal connections of the PZ GABAergic neurons with their input and output nuclei. The newly-found inputs and outputs of the PZ were also listed compared with the literature. This cell-type-specific neuronal whole-brain mapping of the PZ GABAergic neurons may reveal the circuits underlying various functions such as sleep-wake regulation.


Subject(s)
Animals , Axons , Physiology , Brain , Brain Mapping , Brain Stem , Cell Biology , GABAergic Neurons , Physiology , Green Fluorescent Proteins , Genetics , Metabolism , Mice , Mice, Inbred C57BL , Mice, Transgenic , Neural Pathways , Physiology , Peptide Elongation Factor 1 , Genetics , Metabolism , Rabies virus , Genetics , Metabolism , Transduction, Genetic , Vesicular Inhibitory Amino Acid Transport Proteins , Genetics , Metabolism
20.
Neuroscience Bulletin ; (6): 497-506, 2018.
Article in English | WPRIM | ID: wpr-777033

ABSTRACT

Attention deficit hyperactivity disorder (ADHD) is a common childhood neuropsychiatric disorder that has been linked to the dopaminergic system. This study aimed to investigate the effects of regulation of the dopamine D4 receptor (DRD4) on functional brain activity during the resting state in ADHD children using the methods of regional homogeneity (ReHo) and functional connectivity (FC). Resting-state functional magnetic resonance imaging data were analyzed in 49 children with ADHD. All participants were classified as either carriers of the DRD4 4-repeat/4-repeat (4R/4R) allele (n = 30) or the DRD4 2-repeat (2R) allele (n = 19). The results showed that participants with the DRD4 2R allele had decreased ReHo bilaterally in the posterior lobes of the cerebellum, while ReHo was increased in the left angular gyrus. Compared with participants carrying the DRD4 4R/4R allele, those with the DRD4 2R allele showed decreased FC to the left angular gyrus in the left striatum, right inferior frontal gyrus, and bilateral lobes of the cerebellum. The increased FC regions included the left superior frontal gyrus, medial frontal gyrus, and rectus gyrus. These data suggest that the DRD4 polymorphisms are associated with localized brain activity and specific functional connections, including abnormality in the frontal-striatal-cerebellar loop. Our study not only enhances the understanding of the correlation between the cerebellar lobes and ADHD, but also provides an imaging basis for explaining the neural mechanisms underlying ADHD in children.


Subject(s)
Attention Deficit Disorder with Hyperactivity , Diagnostic Imaging , Genetics , Pathology , Brain , Diagnostic Imaging , Cerebellum , Diagnostic Imaging , Child , Corpus Striatum , Diagnostic Imaging , Female , Frontal Lobe , Diagnostic Imaging , Genotype , Humans , Image Processing, Computer-Assisted , Magnetic Resonance Imaging , Male , Minisatellite Repeats , Genetics , Neural Pathways , Diagnostic Imaging , Oxygen , Blood , Receptors, Dopamine D4 , Genetics , Metabolism , Rest
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