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1.
Clin Anat ; 33(1): 66-76, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31573101

RESUMO

The anatomy of the pallidothalamic tracts, including the ansa lenticularis, lenticular fasciculus, and thalamic fasciculus (field H1 of Forel), should be elucidated by neurosurgeons and neuroscientists who study deep brain stimulation. In this study, serially sectioned images of a human cadaver head were employed to overcome the limitations of existing methods to observe the pallidothalamic tracts. Owing to the high resolution and real color of the sectioned images, 28 structures, including the pallidothalamic tracts and mammillothalamic fasciculus, were identified. The structures were segmented and made into surface models, which are helpful in improving the stereoscopic understanding. Observing the sectioned images and surface models may help in understanding the detailed anatomy of the pallidothalamic tracts. The new findings, such as the spatial relationship of the tracts, were summarized in a schematic figure. Moreover, to elucidate the anatomical structures along the course of deep brain stimulation, virtual electrodes were inserted into the surface models. The sectioned images and surface models of this study are expected to enhance the understanding of the pallidothalamic tract anatomy. A portable document format file containing the surface models and the sectioned images can be freely downloaded from the authors' homepage. Clin. Anat. 32:66-76, 2019. © 2019 Wiley Periodicals, Inc.


Assuntos
Globo Pálido/anatomia & histologia , Modelos Anatômicos , Vias Neurais/anatomia & histologia , Subtálamo/anatomia & histologia , Tálamo/anatomia & histologia , Cadáver , Humanos , Processamento de Imagem Assistida por Computador , Imagem Tridimensional
2.
PLoS Comput Biol ; 15(12): e1007551, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31841504

RESUMO

Dynamic communication and routing play important roles in the human brain in order to facilitate flexibility in task solving and thought processes. Here, we present a network perturbation methodology that allows investigating dynamic switching between different network pathways based on phase offsets between two external oscillatory drivers. We apply this method in a computational model of the human connectome with delay-coupled neural masses. To analyze dynamic switching of pathways, we define four new metrics that measure dynamic network response properties for pairs of stimulated nodes. Evaluating these metrics for all network pathways, we found a broad spectrum of pathways with distinct dynamic properties and switching behaviors. We show that network pathways can have characteristic timescales and thus specific preferences for the phase lag between the regions they connect. Specifically, we identified pairs of network nodes whose connecting paths can either be (1) insensitive to the phase relationship between the node pair, (2) turned on and off via changes in the phase relationship between the node pair, or (3) switched between via changes in the phase relationship between the node pair. Regarding the latter, we found that 33% of node pairs can switch their communication from one pathway to another depending on their phase offsets. This reveals a potential mechanistic role that phase offsets and coupling delays might play for the dynamic information routing via communication pathways in the brain.


Assuntos
Conectoma , Modelos Neurológicos , Rede Nervosa/fisiologia , Encéfalo/anatomia & histologia , Encéfalo/fisiologia , Comunicação , Biologia Computacional , Simulação por Computador , Conectoma/estatística & dados numéricos , Humanos , Rede Nervosa/anatomia & histologia , Vias Neurais/anatomia & histologia , Vias Neurais/fisiologia
3.
Handb Clin Neurol ; 163: 95-122, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31590750

RESUMO

Throughout evolution the frontal lobes have progressively acquired a central role in most aspects of cognition and behavior. In humans, frontal lobe functions are conditional on the development of an intricate set of short- and long-range connections that guarantee direct access to sensory information and control over regions dedicated to planning and motor execution. Here the frontal cortical anatomy and the major connections that constitute the local and extended frontal connectivity are reviewed in the context of diffusion tractography studies, contemporary models of frontal lobe functions, and clinical syndromes. A particular focus of this chapter is the use of comparative anatomy and neurodevelopmental data to address the question of how frontal networks evolved and what this signified for unique human abilities.


Assuntos
Lobo Frontal/anatomia & histologia , Rede Nervosa/anatomia & histologia , Mapeamento Encefálico , Imagem de Tensor de Difusão , Lobo Frontal/diagnóstico por imagem , Humanos , Rede Nervosa/diagnóstico por imagem , Vias Neurais/anatomia & histologia , Vias Neurais/diagnóstico por imagem
4.
Elife ; 82019 10 08.
Artigo em Inglês | MEDLINE | ID: mdl-31591961

RESUMO

For many species, hunting is an innate behaviour that is crucial for survival, yet the circuits that control predatory action sequences are poorly understood. We used larval zebrafish to identify a population of pretectal neurons that control hunting. By combining calcium imaging with a virtual hunting assay, we identified a discrete pretectal region that is selectively active when animals initiate hunting. Targeted genetic labelling allowed us to examine the function and morphology of individual cells and identify two classes of pretectal neuron that project to ipsilateral optic tectum or the contralateral tegmentum. Optogenetic stimulation of single neurons of either class was able to induce sustained hunting sequences, in the absence of prey. Furthermore, laser ablation of these neurons impaired prey-catching and prevented induction of hunting by optogenetic stimulation of the anterior-ventral tectum. We propose that this specific population of pretectal neurons functions as a command system to induce predatory behaviour.


Assuntos
Neurônios/fisiologia , Comportamento Predatório , Área Pré-Tectal/fisiologia , Animais , Mapeamento Encefálico , Vias Neurais/anatomia & histologia , Vias Neurais/fisiologia , Imagem Óptica , Optogenética , Área Pré-Tectal/anatomia & histologia , Coloração e Rotulagem , Peixe-Zebra
5.
Nat Commun ; 10(1): 4747, 2019 10 18.
Artigo em Inglês | MEDLINE | ID: mdl-31628329

RESUMO

The brain is an assembly of neuronal populations interconnected by structural pathways. Brain activity is expressed on and constrained by this substrate. Therefore, statistical dependencies between functional signals in directly connected areas can be expected higher. However, the degree to which brain function is bound by the underlying wiring diagram remains a complex question that has been only partially answered. Here, we introduce the structural-decoupling index to quantify the coupling strength between structure and function, and we reveal a macroscale gradient from brain regions more strongly coupled, to regions more strongly decoupled, than expected by realistic surrogate data. This gradient spans behavioral domains from lower-level sensory function to high-level cognitive ones and shows for the first time that the strength of structure-function coupling is spatially varying in line with evidence derived from other modalities, such as functional connectivity, gene expression, microstructural properties and temporal hierarchy.


Assuntos
Encéfalo/fisiologia , Córtex Cerebral/fisiologia , Rede Nervosa/fisiologia , Neurônios/fisiologia , Algoritmos , Encéfalo/anatomia & histologia , Encéfalo/citologia , Mapeamento Encefálico/métodos , Córtex Cerebral/anatomia & histologia , Córtex Cerebral/citologia , Humanos , Imagem por Ressonância Magnética , Modelos Neurológicos , Rede Nervosa/anatomia & histologia , Rede Nervosa/citologia , Vias Neurais/anatomia & histologia , Vias Neurais/citologia , Vias Neurais/fisiologia
6.
Nat Neurosci ; 22(11): 1925-1935, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31527803

RESUMO

The thalamus is the central communication hub of the forebrain and provides the cerebral cortex with inputs from sensory organs, subcortical systems and the cortex itself. Multiple thalamic regions send convergent information to each cortical region, but the organizational logic of thalamic projections has remained elusive. Through comprehensive transcriptional analyses of retrogradely labeled thalamic neurons in adult mice, we identify three major profiles of thalamic pathways. These profiles exist along a continuum that is repeated across all major projection systems, such as those for vision, motor control and cognition. The largest component of gene expression variation in the mouse thalamus is topographically organized, with features conserved in humans. Transcriptional differences between these thalamic neuronal identities are tied to cellular features that are critical for function, such as axonal morphology and membrane properties. Molecular profiling therefore reveals covariation in the properties of thalamic pathways serving all major input modalities and output targets, thus establishing a molecular framework for understanding the thalamus.


Assuntos
Córtex Cerebral/anatomia & histologia , Tálamo/anatomia & histologia , Potenciais de Ação , Animais , Atlas como Assunto , Córtex Cerebral/metabolismo , Córtex Cerebral/fisiologia , Humanos , Camundongos , Camundongos Transgênicos , Vias Neurais/anatomia & histologia , Vias Neurais/metabolismo , Vias Neurais/fisiologia , Tálamo/metabolismo , Tálamo/fisiologia , Transcriptoma
7.
Elife ; 82019 09 06.
Artigo em Inglês | MEDLINE | ID: mdl-31490123

RESUMO

Cortico-basal ganglia-thalamocortical loops are largely conceived as parallel circuits that process limbic, associative, and sensorimotor information separately. Whether and how these functionally distinct loops interact remains unclear. Combining genetic and viral approaches, we systemically mapped the limbic and motor cortico-basal ganglia-thalamocortical loops in rodents. Despite largely closed loops within each functional domain, we discovered a unidirectional influence of the limbic over the motor loop via ventral striatum-substantia nigra (SNr)-motor thalamus circuitry. Slice electrophysiology verifies that the projection from ventral striatum functionally inhibits nigro-thalamic SNr neurons. In vivo optogenetic stimulation of ventral or dorsolateral striatum to SNr pathway modulates activity in medial prefrontal cortex (mPFC) and motor cortex (M1), respectively. However, whereas the dorsolateral striatum-SNr pathway exerts little impact on mPFC, activation of the ventral striatum-SNr pathway effectively alters M1 activity. These results demonstrate an open cortico-basal ganglia loop whereby limbic information could modulate motor output through ventral striatum control of M1.


Assuntos
Gânglios da Base/fisiologia , Sistema Límbico/fisiologia , Córtex Motor/fisiologia , Vias Neurais/fisiologia , Substância Negra/fisiologia , Animais , Gânglios da Base/anatomia & histologia , Fenômenos Eletrofisiológicos , Sistema Límbico/anatomia & histologia , Camundongos , Córtex Motor/anatomia & histologia , Vias Neurais/anatomia & histologia , Ratos , Substância Negra/anatomia & histologia
8.
Brain Struct Funct ; 224(8): 2839-2855, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31440906

RESUMO

In humans, sensorimotor cortical areas receive relevant dopaminergic innervation-although an anatomic description of the underlying fiber projections is lacking so far. In general, dopaminergic projections towards the cortex originate within the ventral tegmental area (VTA) and are organized in a meso-cortico-limbic system. Using a DTI-based global tractography approach, we recently characterized the superolateral branch of the medial forebrain bundle (slMFB), a prominent pathway providing dopaminergic (and other transmitters) innervation for the pre-frontal cortex (Coenen et al., NeuroImage Clin 18:770-783, 2018). To define the connections between VTA and sensory-motor cortical fields that should contain dopaminergic fibers, we use the slMFB as a key structure to lead our fiber selection procedure: using a similar tracking-seed and tractography algorithm, we describe a dorsal extension of this slMFB that covers sensorimotor fields that are dorsally appended to pre-frontal cortical areas. This "motorMFB", that connects the VTA to sensorimotor cortical fields, can be further segregated into three sub-bundles with a seed-based fiber-selection strategy: A PFC bundle that is attendant to the pre-frontal cortex, passes the lateral VTA, runs through the border zone between the posterior and lateral ventral thalamic nucleus, and involves the pre- and postcentral gyrus. An MB bundle that is attendant to the mammillary bodies runs directly through the medial VTA, passes the lateral ventral thalamic nucleus, and involves the pre- and postcentral gyrus as well as the supplementary motor area (SMA) and the dorsal premotor cortex (dPMC). Finally, a BC bundle that is attendant to the brainstem and cerebellum runs through the lateral VTA, passes the anterior ventral thalamic nucleus, and covers the SMA, pre-SMA, and the dPMC. We, furthermore, included a fiber tracking of the well-defined dentato-rubro-thalamic tract (DRT) that is known to lie in close proximity with respect to fiber orientation and projection areas. As expected, the tract is characterized by a decussation at the ponto-mesencephal level and a projection covering the superior-frontal and precentral cortex. In addition to the physiological role of these particular bundles, the physiological and pathophysiological impact of dopaminergic signaling within sensorimotor cortical fields becomes discussed. However, some limitations have to be taken into account in consequence of the method: the transmitter content, the directionality, and the occurrence of interposed synaptic contacts cannot be specified.


Assuntos
Neurônios Dopaminérgicos , Córtex Sensório-Motor/anatomia & histologia , Área Tegmentar Ventral/anatomia & histologia , Adulto , Encéfalo/anatomia & histologia , Conectoma/métodos , Imagem de Difusão por Ressonância Magnética , Humanos , Masculino , Feixe Prosencefálico Mediano/anatomia & histologia , Vias Neurais/anatomia & histologia
9.
Elife ; 82019 08 27.
Artigo em Inglês | MEDLINE | ID: mdl-31453803

RESUMO

Lineage regulates the synaptic connections between neurons in some regions of the invertebrate nervous system. In mammals, recent experiments suggest that cell lineage determines the connectivity of pyramidal neurons in the neocortex, but the functional relevance of this phenomenon and whether it occurs in other neuronal types remains controversial. We investigated whether lineage plays a role in the connectivity of mitral and tufted cells, the projection neurons in the mouse olfactory bulb. We used transgenic mice to sparsely label neuronal progenitors and observed that clonally related neurons receive synaptic input from olfactory sensory neurons expressing different olfactory receptors. These results indicate that lineage does not determine the connectivity between olfactory sensory neurons and olfactory bulb projection neurons.


Assuntos
Interneurônios/fisiologia , Vias Neurais/anatomia & histologia , Vias Neurais/fisiologia , Bulbo Olfatório/anatomia & histologia , Bulbo Olfatório/fisiologia , Neurônios Receptores Olfatórios/fisiologia , Animais , Camundongos , Camundongos Transgênicos
10.
J Clin Neurosci ; 68: 290-294, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31331747

RESUMO

The Inferior Fronto-Occipital fascicle (IFOF) is a multitasking white matter (WM) bundle bridging frontal, temporal, parietal and occipital lobe. Many papers describe its role in the physiology of language, attention and affective behavior but its anatomical components and cortical terminations remain unclear. We analyze the surgical anatomy of the IFOF in the light of our experience with awake surgery, anatomical dissection on 10 human adult hemispheres (Klingler method) and literature review. Dissecting the specimens from lateral to medial we can describe 3 segments: a vertical segment that runs along the frontal lobe; an horizontal segment that runs along frontal lobe; an horizontal segment that runs from the limen insulae, passes into to the temporal stem and arrives at the parietal and occipital lobes. We retrospectively analyzed also 23 awake surgeries. 2 responses were elicited at subcortical stimulation at the third segment of the IFOF; stimulation gave paraphasias on the first segment of the IFOF in one case. All IFOF responses were founded in the left hemisphere. Anatomical knowledge is the cornerstone of surgical orientation, it allows eloquent structures to be reached quickly and it is of primary importance in awake surgery to avoid patient fatigue with lack of concentration.


Assuntos
Encéfalo/anatomia & histologia , Vias Neurais/anatomia & histologia , Substância Branca/anatomia & histologia , Adulto , Encéfalo/cirurgia , Neoplasias Encefálicas/cirurgia , Feminino , Humanos , Monitorização Neurofisiológica Intraoperatória , Masculino , Procedimentos Neurocirúrgicos/métodos , Estudos Retrospectivos
11.
Turk Neurosurg ; 29(6): 864-874, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31353435

RESUMO

AIM: To describe the location of each white matter pathways around the temporo-parieto-occipital junction (TPOJ) and the dissections performed using focal fiber dissection and fiber separation techniques (FST). These areas play an important role in human language processing and high-level brain functions. Thus, it is important to identify the association of the fascicles as well as their courses to plan safe and effective surgical target vectors. MATERIAL AND METHODS: Thirty formalin-fixed human hemispheres and two formalin-fixed human heads were dissected with focal fiber dissection and FST under 6-40x magnification using a surgical microscope and real-time magnetic resonance imaging navigation system. Two- and three-dimensional anatomical and surgical pictures were obtained and processed using high dynamic range photography (Photomatix) and were correlated to radiological images of the case with glioblastoma of the TPOJ. RESULTS: The trajectory and connectivity of these fibers as well as their surgical importance in performing FST in cadaver dissections were demonstrated with correlation of the surgical, radiological, and anatomical images. CONCLUSION: The microanatomy of the TPOJ and related structures, emphasizing the position of each white matter pathway, has been described. Understanding the composition of each region is critical in preventing intraoperative brain injury that could lead to functional deficits.


Assuntos
Neoplasias Encefálicas/diagnóstico por imagem , Glioblastoma/diagnóstico por imagem , Lobo Occipital/anatomia & histologia , Lobo Parietal/anatomia & histologia , Lobo Temporal/anatomia & histologia , Substância Branca/anatomia & histologia , Neoplasias Encefálicas/cirurgia , Cadáver , Dissecação/métodos , Glioblastoma/cirurgia , Humanos , Masculino , Pessoa de Meia-Idade , Fibras Nervosas Mielinizadas , Vias Neurais/anatomia & histologia , Vias Neurais/diagnóstico por imagem , Vias Neurais/cirurgia , Lobo Occipital/diagnóstico por imagem , Lobo Parietal/diagnóstico por imagem , Lobo Parietal/cirurgia , Lobo Temporal/diagnóstico por imagem , Lobo Temporal/cirurgia , Substância Branca/diagnóstico por imagem , Substância Branca/cirurgia
12.
Brain Struct Funct ; 224(8): 2631-2660, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31342157

RESUMO

Historically, the primary focus of studies of human white matter tracts has been on large tracts that connect anterior-to-posterior cortical regions. These include the superior longitudinal fasciculus (SLF), the inferior longitudinal fasciculus (ILF), and the inferior fronto-occipital fasciculus (IFOF). Recently, more refined and well-understood tractography methods have facilitated the characterization of several tracts in the posterior of the human brain that connect dorsal-to-ventral cortical regions. These include the vertical occipital fasciculus (VOF), the posterior arcuate fasciculus (pArc), the temporo-parietal connection (TP-SPL), and the middle longitudinal fasciculus (MdLF). The addition of these dorso-ventral connective tracts to our standard picture of white matter architecture results in a more complicated pattern of white matter connectivity than previously considered. Dorso-ventral connective tracts may play a role in transferring information from superior horizontal tracts, such as the SLF, to inferior horizontal tracts, such as the IFOF and ILF. We present a full anatomical delineation of these major dorso-ventral connective white matter tracts (the VOF, pArc, TP-SPL, and MdLF). We show their spatial layout and cortical termination mappings in relation to the more established horizontal tracts (SLF, IFOF, ILF, and Arc) and consider standard values for quantitative features associated with the aforementioned tracts. We hope to facilitate further study on these tracts and their relations. To this end, we also share links to automated code that segments these tracts, thereby providing a standard approach to obtaining these tracts for subsequent analysis. We developed open source software to allow reproducible segmentation of the tracts: https://github.com/brainlife/Vertical_Tracts . Finally, we make the segmentation method available as an open cloud service on the data and analyses sharing platform brainlife.io. Investigators will be able to access these services and upload their data to segment these tracts.


Assuntos
Encéfalo/anatomia & histologia , Substância Branca/anatomia & histologia , Encéfalo/diagnóstico por imagem , Imagem de Difusão por Ressonância Magnética , Humanos , Processamento de Imagem Assistida por Computador , Masculino , Vias Neurais/anatomia & histologia , Vias Neurais/diagnóstico por imagem , Software , Substância Branca/diagnóstico por imagem
13.
Elife ; 82019 06 17.
Artigo em Inglês | MEDLINE | ID: mdl-31205000

RESUMO

Multiple lines of evidence suggest that functionally intact cerebello-hippocampal interactions are required for appropriate spatial processing. However, how the cerebellum anatomically and physiologically engages with the hippocampus to sustain such communication remains unknown. Using rabies virus as a retrograde transneuronal tracer in mice, we reveal that the dorsal hippocampus receives input from topographically restricted and disparate regions of the cerebellum. By simultaneously recording local field potential from both the dorsal hippocampus and anatomically connected cerebellar regions, we additionally suggest that the two structures interact, in a behaviorally dynamic manner, through subregion-specific synchronization of neuronal oscillations in the 6-12 Hz frequency range. Together, these results reveal a novel neural network macro-architecture through which we can understand how a brain region classically associated with motor control, the cerebellum, may influence hippocampal neuronal activity and related functions, such as spatial navigation.


Assuntos
Cerebelo/fisiologia , Hipocampo/fisiologia , Rede Nervosa/fisiologia , Vias Neurais/fisiologia , Animais , Cerebelo/anatomia & histologia , Cerebelo/virologia , Estimulação Elétrica , Hipocampo/anatomia & histologia , Hipocampo/virologia , Masculino , Camundongos Endogâmicos C57BL , Rede Nervosa/anatomia & histologia , Rede Nervosa/virologia , Vias Neurais/anatomia & histologia , Vias Neurais/virologia , Neurônios/fisiologia , Neurônios/virologia , Raiva/fisiopatologia , Raiva/virologia , Vírus da Raiva/fisiologia , Navegação Espacial/fisiologia
14.
Neuroimage ; 198: 231-241, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31102735

RESUMO

Diffusion tractography is routinely used to study white matter architecture and brain connectivity in vivo. A key step for successful tractography of neuronal tracts is the correct identification of tract directions in each voxel. Here we propose a fingerprinting-based methodology to identify these fiber directions in Orientation Distribution Functions, dubbed ODF-Fingerprinting (ODF-FP). In ODF-FP, fiber configurations are selected based on the similarity between measured ODFs and elements in a pre-computed library. In noisy ODFs, the library matching algorithm penalizes the more complex fiber configurations. ODF simulations and analysis of bootstrapped partial and whole-brain in vivo datasets show that the ODF-FP approach improves the detection of fiber pairs with small crossing angles while maintaining fiber direction precision, which leads to better tractography results. Rather than focusing on the ODF maxima, the ODF-FP approach uses the whole ODF shape to infer fiber directions to improve the detection of fiber bundles with small crossing angle. The resulting fiber directions aid tractography algorithms in accurately displaying neuronal tracts and calculating brain connectivity.


Assuntos
Mapeamento Encefálico/métodos , Encéfalo/diagnóstico por imagem , Imagem de Difusão por Ressonância Magnética , Processamento de Imagem Assistida por Computador/métodos , Substância Branca/diagnóstico por imagem , Algoritmos , Encéfalo/anatomia & histologia , Simulação por Computador , Humanos , Vias Neurais/anatomia & histologia , Vias Neurais/diagnóstico por imagem , Reprodutibilidade dos Testes , Razão Sinal-Ruído , Substância Branca/anatomia & histologia
15.
Invert Neurosci ; 19(2): 5, 2019 05 10.
Artigo em Inglês | MEDLINE | ID: mdl-31073644

RESUMO

Here, we report the findings after application of neurobiotin tracing to pallial and stellar nerves in the mantle of the cephalopod mollusk Octopus vulgaris and to the axial nerve cord in its arm. Neurobiotin backfilling is a known technique in other molluscs, but it is applied to octopus for the first time to be best of our knowledge. Different neural tracing techniques have been carried out in cephalopods to study the intricate neural connectivity of their nervous system, but mapping the nervous connections in this taxon is still incomplete, mainly due to the absence of a reliable tracing method allowing whole-mount imaging. In our experiments, neurobiotin backfilling allowed: (1) imaging of large/thick samples (larger than 2 mm) through optical clearing; (2) additional application of immunohistochemistry on the backfilled tissues, allowing identification of neural structures by coupling of a specific antibody. This work opens a series of future studies aimed to the identification of the neural diagram and connectome of octopus nervous system.


Assuntos
Imuno-Histoquímica/métodos , Vias Neurais/anatomia & histologia , Octopodiformes/anatomia & histologia , Animais , Biotina/análogos & derivados , Corantes
16.
Elife ; 82019 05 14.
Artigo em Inglês | MEDLINE | ID: mdl-31084703

RESUMO

Early adverse experiences often have devastating consequences. However, whether preweaning paternal deprivation (PD) affects emotional and social behaviors and their underlying neural mechanisms remain unexplored. Using monogamous mandarin voles, we found that PD increased anxiety-like behavior and attenuated social preference in adulthood. PD also decreased the number of oxytocin (OT)-positive neurons projecting from the paraventricular nucleus (PVN) and reduced the levels of the medial prefrontal cortex OT receptor protein in females and of the OT receptor and V1a receptor proteins in males. Intra-prelimbic cortical OT injections reversed the PD-induced changes in anxiety-like behavior and social preferences. Optogenetic activation of the prelimbic cortex OT terminals from PVN OT neurons reversed the PD-induced changes in emotion and social preference behaviors, whereas optogenetic inhibition was anxiogenic and impaired social preference in naive voles. These findings demonstrate that PD increases anxiety-like behavior and attenuates social preferences through the involvement of PVN OT neuron projections to the prelimbic cortex.


Assuntos
Ansiedade , Vias Neurais/anatomia & histologia , Núcleo Hipotalâmico Paraventricular/anatomia & histologia , Privação Paterna , Comportamento Social , Animais , Arvicolinae , Feminino , Masculino , Neurônios/química , Receptores de Ocitocina/análise , Receptores de Vasopressinas/análise
17.
Neuroimage ; 198: 137-149, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31077843

RESUMO

Dysregulation of the nucleus accumbens (NAc) is implicated in numerous neuropsychiatric disorders. Treatments targeting this area directly (e.g. deep brain stimulation) demonstrate variable efficacy, perhaps owing to non-specific targeting of a functionally heterogeneous nucleus. Here we provide support for this notion, first observing disparate behavioral effects in response to direct simulation of different locations within the NAc in a human patient. These observations motivate a segmentation of the NAc into subregions, which we produce from a diffusion-tractography based analysis of 245 young, unrelated healthy subjects. We further explore the mechanism of these stimulation-induced behavioral responses by identifying the most probable subset of axons activated using a patient-specific computational model. We validate our diffusion-based segmentation using evidence from several modalities, including MRI-based measures of function and microstructure, human post-mortem immunohistochemical staining, and cross-species comparison of cortical-NAc projections that are known to be conserved. Finally, we visualize the passage of individual axon bundles through one NAc subregion in a post-mortem human sample using CLARITY 3D histology corroborated by 7T tractography. Collectively, these findings extensively characterize human NAc subregions and provide insight into their structural and functional distinctions with implications for stereotactic treatments targeting this region.


Assuntos
Axônios/fisiologia , Córtex Cerebral/anatomia & histologia , Córtex Cerebral/fisiologia , Núcleo Accumbens/anatomia & histologia , Núcleo Accumbens/fisiologia , Animais , Mapeamento Encefálico/métodos , Córtex Cerebral/diagnóstico por imagem , Imagem de Tensor de Difusão , Estimulação Elétrica , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Masculino , Camundongos , Modelos Neurológicos , Vias Neurais/anatomia & histologia , Vias Neurais/diagnóstico por imagem , Vias Neurais/fisiologia , Núcleo Accumbens/diagnóstico por imagem
18.
Neuroimage ; 199: 1-17, 2019 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-31132451

RESUMO

The ongoing myelination of white-matter fiber bundles plays a significant role in brain development. However, reliable and consistent identification of these bundles from infant brain MRIs is often challenging due to inherently low diffusion anisotropy, as well as motion and other artifacts. In this paper we introduce a new tool for automated probabilistic tractography specifically designed for newborn infants. Our tool incorporates prior information about the anatomical neighborhood of white-matter pathways from a training data set. In our experiments, we evaluate this tool on data from both full-term and prematurely born infants and demonstrate that it can reconstruct known white-matter tracts in both groups robustly, even in the presence of differences between the training set and study subjects. Additionally, we evaluate it on a publicly available large data set of healthy term infants (UNC Early Brain Development Program). This paves the way for performing a host of sophisticated analyses in newborns that we have previously implemented for the adult brain, such as pointwise analysis along tracts and longitudinal analysis, in both health and disease.


Assuntos
Imagem de Tensor de Difusão/métodos , Neuroimagem/métodos , Substância Branca/anatomia & histologia , Substância Branca/diagnóstico por imagem , Feminino , Humanos , Lactente , Recém-Nascido , Criança Pós-Termo , Masculino , Vias Neurais/anatomia & histologia , Vias Neurais/diagnóstico por imagem
19.
World Neurosurg ; 129: 407-420, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31132493

RESUMO

OBJECTIVE: To analyze the three-dimensional relationships of the operculoinsular compartments, using standard hemispheric and white matter fiber dissection and review the anatomy of association fibers related to the operculoinsular compartments of the Sylvian fissure and the main white matter tracts located deep into the insula. The secondary aim of this study was to improve the knowledge on this complex region to safely address tumor, vascular, and epilepsy lesions with an integrated perspective of the topographic and white matter fiber anatomy using 2D and 3D photographs. METHODS: Six cadaveric hemispheres were dissected. Two were fixed with formalin and the arteries were injected with red latex dye; the remaining four were prepared using the Kingler method and white fiber dissections were performed. RESULTS: The insula is located entirely inside the Sylvian fissure. The topographic hemispheric anatomy, Sylvian fissure, opercula, surrounding sulci and gyri, as well as the M2, M3, and M4 segments were identified. The anatomy of the insula, with the sulci and gyri and the limiting sulci, were also identified and described. The main white matter fiber tracts of the operculoinsular compartments of the Sylvian fissure as well as the main association and commissural fibers located deep in the insula were dissected and demonstrated. CONCLUSIONS: Complementing topographic anatomy with detailed study of white matter fibers and their integration can help the neurosurgeon to safely approach lesions in the insular region, improving postoperative results in the microsurgical treatment of aneurysmal lesions, insular tumors, or epilepsy surgery.


Assuntos
Córtex Cerebral/anatomia & histologia , Córtex Cerebral/cirurgia , Vias Neurais/anatomia & histologia , Substância Branca/anatomia & histologia , Humanos , Vias Neurais/cirurgia , Substância Branca/cirurgia
20.
Nat Neurosci ; 22(6): 909-920, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31127260

RESUMO

Predatory hunting plays a fundamental role in animal survival. Little is known about the neural circuits that convert sensory cues into neural signals to drive this behavior. Here we identified an excitatory subcortical neural circuit from the superior colliculus to the zona incerta that triggers predatory hunting. The superior colliculus neurons that form this pathway integrate motion-related visual and vibrissal somatosensory cues of prey. During hunting, these neurons send out neural signals that are temporally correlated with predatory attacks, but not with feeding after prey capture. Synaptic inactivation of this pathway selectively blocks hunting for prey without impairing other sensory-triggered behaviors. These data reveal a subcortical neural circuit that is specifically engaged in translating sensory cues into neural signals to provoke predatory hunting.


Assuntos
Vias Neurais/fisiologia , Comportamento Predatório/fisiologia , Colículos Superiores/fisiologia , Zona Incerta/fisiologia , Animais , Camundongos , Vias Neurais/anatomia & histologia , Neurônios/citologia , Neurônios/fisiologia , Colículos Superiores/anatomia & histologia , Zona Incerta/anatomia & histologia
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