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1.
Cell ; 2024 Sep 17.
Artigo em Inglês | MEDLINE | ID: mdl-39303715

RESUMO

Identifying the properties of the rapid eye movement (REM) sleep circuitry and its relation to diseases has been challenging due to the neuronal heterogeneity of the brainstem. Here, we show in mice that neurons in the pontine sublaterodorsal tegmentum (SubLDT) that express corticotropin-releasing hormone-binding protein (Crhbp+ neurons) and project to the medulla promote REM sleep. Within the medullary area receiving projections from Crhbp+ neurons, neurons expressing nitric oxide synthase 1 (Nos1+ neurons) project to the SubLDT and promote REM sleep, suggesting a positively interacting loop between the pons and the medulla operating as a core REM sleep circuit. Nos1+ neurons also project to areas that control wide forebrain activity. Ablating Crhbp+ neurons reduces sleep and impairs REM sleep atonia. In Parkinson's disease patients with REM sleep behavior disorders, CRHBP-immunoreactive neurons are largely reduced and contain pathologic α-synuclein, providing insight into the mechanisms underlying the sleep deficits characterizing this disease.

2.
Cell ; 186(1): 162-177.e18, 2023 01 05.
Artigo em Inglês | MEDLINE | ID: mdl-36608651

RESUMO

The cortex influences movement by widespread top-down projections to many nervous system regions. Skilled forelimb movements require brainstem circuitry in the medulla; however, the logic of cortical interactions with these neurons remains unexplored. Here, we reveal a fine-grained anatomical and functional map between anterior cortex (AC) and medulla in mice. Distinct cortical regions generate three-dimensional synaptic columns tiling the lateral medulla, topographically matching the dorso-ventral positions of postsynaptic neurons tuned to distinct forelimb action phases. Although medial AC (MAC) terminates ventrally and connects to forelimb-reaching-tuned neurons and its silencing impairs reaching, lateral AC (LAC) influences dorsally positioned neurons tuned to food handling, and its silencing impairs handling. Cortico-medullary neurons also extend collaterals to other subcortical structures through a segregated channel interaction logic. Our findings reveal a precise alignment between cortical location, its function, and specific forelimb-action-tuned medulla neurons, thereby clarifying interaction principles between these two key structures and beyond.


Assuntos
Movimento , Neurônios , Camundongos , Animais , Movimento/fisiologia , Neurônios/fisiologia , Membro Anterior/fisiologia , Tronco Encefálico
3.
Cell ; 185(26): 5011-5027.e20, 2022 12 22.
Artigo em Inglês | MEDLINE | ID: mdl-36563666

RESUMO

To track and control self-location, animals integrate their movements through space. Representations of self-location are observed in the mammalian hippocampal formation, but it is unknown if positional representations exist in more ancient brain regions, how they arise from integrated self-motion, and by what pathways they control locomotion. Here, in a head-fixed, fictive-swimming, virtual-reality preparation, we exposed larval zebrafish to a variety of involuntary displacements. They tracked these displacements and, many seconds later, moved toward their earlier location through corrective swimming ("positional homeostasis"). Whole-brain functional imaging revealed a network in the medulla that stores a memory of location and induces an error signal in the inferior olive to drive future corrective swimming. Optogenetically manipulating medullary integrator cells evoked displacement-memory behavior. Ablating them, or downstream olivary neurons, abolished displacement corrections. These results reveal a multiregional hindbrain circuit in vertebrates that integrates self-motion and stores self-location to control locomotor behavior.


Assuntos
Neurônios , Peixe-Zebra , Animais , Peixe-Zebra/fisiologia , Neurônios/fisiologia , Rombencéfalo/fisiologia , Encéfalo/fisiologia , Natação/fisiologia , Homeostase , Mamíferos
4.
Cell ; 184(17): 4564-4578.e18, 2021 08 19.
Artigo em Inglês | MEDLINE | ID: mdl-34302739

RESUMO

The mesencephalic locomotor region (MLR) is a key midbrain center with roles in locomotion. Despite extensive studies and clinical trials aimed at therapy-resistant Parkinson's disease (PD), debate on its function remains. Here, we reveal the existence of functionally diverse neuronal populations with distinct roles in control of body movements. We identify two spatially intermingled glutamatergic populations separable by axonal projections, mouse genetics, neuronal activity profiles, and motor functions. Most spinally projecting MLR neurons encoded the full-body behavior rearing. Loss- and gain-of-function optogenetic perturbation experiments establish a function for these neurons in controlling body extension. In contrast, Rbp4-transgene-positive MLR neurons project in an ascending direction to basal ganglia, preferentially encode the forelimb behaviors handling and grooming, and exhibit a role in modulating movement. Thus, the MLR contains glutamatergic neuronal subpopulations stratified by projection target exhibiting roles in action control not restricted to locomotion.


Assuntos
Locomoção/fisiologia , Mesencéfalo/anatomia & histologia , Animais , Gânglios da Base/metabolismo , Comportamento Animal , Feminino , Integrases/metabolismo , Masculino , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Neurônios/metabolismo , Optogenética , Proteínas Plasmáticas de Ligação ao Retinol/metabolismo , Medula Espinal/metabolismo , Transgenes , Proteína Vesicular 2 de Transporte de Glutamato/metabolismo
5.
Cell ; 184(22): 5608-5621.e18, 2021 10 28.
Artigo em Inglês | MEDLINE | ID: mdl-34637701

RESUMO

Mammals use glabrous (hairless) skin of their hands and feet to navigate and manipulate their environment. Cortical maps of the body surface across species contain disproportionately large numbers of neurons dedicated to glabrous skin sensation, in part reflecting a higher density of mechanoreceptors that innervate these skin regions. Here, we find that disproportionate representation of glabrous skin emerges over postnatal development at the first synapse between peripheral mechanoreceptors and their central targets in the brainstem. Mechanoreceptor synapses undergo developmental refinement that depends on proximity of their terminals to glabrous skin, such that those innervating glabrous skin make synaptic connections that expand their central representation. In mice incapable of sensing gentle touch, mechanoreceptors innervating glabrous skin still make more powerful synapses in the brainstem. We propose that the skin region a mechanoreceptor innervates controls the developmental refinement of its central synapses to shape the representation of touch in the brain.


Assuntos
Tronco Encefálico/metabolismo , Mecanorreceptores/metabolismo , Sinapses/metabolismo , Percepção do Tato/fisiologia , Potenciais de Ação/fisiologia , Animais , Animais Recém-Nascidos , Axônios/metabolismo , Canais Iônicos/metabolismo , Camundongos Knockout , Neurônios/metabolismo , Imagem Óptica , Optogenética , Pele/inervação
6.
Cell ; 172(5): 952-965.e18, 2018 02 22.
Artigo em Inglês | MEDLINE | ID: mdl-29474921

RESUMO

Viruses that are typically benign sometimes invade the brainstem in otherwise healthy children. We report bi-allelic DBR1 mutations in unrelated patients from different ethnicities, each of whom had brainstem infection due to herpes simplex virus 1 (HSV1), influenza virus, or norovirus. DBR1 encodes the only known RNA lariat debranching enzyme. We show that DBR1 expression is ubiquitous, but strongest in the spinal cord and brainstem. We also show that all DBR1 mutant alleles are severely hypomorphic, in terms of expression and function. The fibroblasts of DBR1-mutated patients contain higher RNA lariat levels than control cells, this difference becoming even more marked during HSV1 infection. Finally, we show that the patients' fibroblasts are highly susceptible to HSV1. RNA lariat accumulation and viral susceptibility are rescued by wild-type DBR1. Autosomal recessive, partial DBR1 deficiency underlies viral infection of the brainstem in humans through the disruption of tissue-specific and cell-intrinsic immunity to viruses.


Assuntos
Encefalopatias Metabólicas Congênitas/genética , Tronco Encefálico/metabolismo , Tronco Encefálico/virologia , RNA/química , RNA/metabolismo , Alelos , Sequência de Aminoácidos , Animais , Encefalopatias Metabólicas Congênitas/patologia , Tronco Encefálico/patologia , Encefalite Viral/genética , Escherichia coli/metabolismo , Feminino , Fibroblastos/metabolismo , Fibroblastos/patologia , Fibroblastos/virologia , Herpesvirus Humano 1 , Humanos , Interferons/metabolismo , Íntrons/genética , Masculino , Camundongos , Proteínas Mutantes/metabolismo , Mutação/genética , Fases de Leitura Aberta/genética , Linhagem , RNA Nucleotidiltransferases/química , RNA Nucleotidiltransferases/deficiência , RNA Nucleotidiltransferases/genética , Receptor 3 Toll-Like/metabolismo , Replicação Viral
7.
Physiol Rev ; 104(1): 85-101, 2024 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-37440208

RESUMO

The prevalence of metabolic disorders, including type 2 diabetes mellitus, continues to increase worldwide. Although newer and more advanced therapies are available, current treatments are still inadequate and the search for solutions remains. The regulation of energy homeostasis, including glucose metabolism, involves an exchange of information between the nervous systems and peripheral organs and tissues; therefore, developing treatments to alter central and/or peripheral neural pathways could be an alternative solution to modulate whole body metabolism. Liver glucose production and storage are major mechanisms controlling glycemia, and the autonomic nervous system plays an important role in the regulation of hepatic functions. Autonomic nervous system imbalance contributes to excessive hepatic glucose production and thus to the development and progression of type 2 diabetes mellitus. At cellular levels, change in neuronal activity is one of the underlying mechanisms of autonomic imbalance; therefore, modulation of the excitability of neurons involved in autonomic outflow governance has the potential to improve glycemic status. Tissue-specific subsets of preautonomic neurons differentially control autonomic outflow; therefore, detailed information about neural circuits and properties of liver-related neurons is necessary for the development of strategies to regulate liver functions via the autonomic nerves. This review provides an overview of our current understanding of the hypothalamus-ventral brainstem-liver pathway involved in the sympathetic regulation of the liver, outlines strategies to identify organ-related neurons, and summarizes neuronal plasticity during diabetic conditions with a particular focus on liver-related neurons in the paraventricular nucleus.


Assuntos
Diabetes Mellitus Tipo 2 , Glucose , Humanos , Glucose/metabolismo , Diabetes Mellitus Tipo 2/metabolismo , Hipotálamo/fisiologia , Núcleo Hipotalâmico Paraventricular/metabolismo , Fígado/metabolismo
8.
Annu Rev Neurosci ; 42: 433-457, 2019 07 08.
Artigo em Inglês | MEDLINE | ID: mdl-31018099

RESUMO

Many mammals, including humans, are exquisitely sensitive to tiny time differences between sounds at the two ears. These interaural time differences are an important source of information for sound detection, for sound localization in space, and for environmental awareness. Two brainstem circuits are involved in the initial temporal comparisons between the ears, centered on the medial and lateral superior olive. Cells in these nuclei, as well as their afferents, display a large number of striking physiological and anatomical specializations to enable submillisecond sensitivity. As such, they provide an important model system to study temporal processing in the central nervous system. We review the progress that has been made in characterizing these primary binaural circuits as well as the variety of mechanisms that have been proposed to underlie their function.


Assuntos
Vias Auditivas/fisiologia , Audição/fisiologia , Núcleo Olivar/fisiologia , Localização de Som/fisiologia , Estimulação Acústica/métodos , Animais , Humanos , Modelos Neurológicos
9.
Annu Rev Neurosci ; 42: 485-504, 2019 07 08.
Artigo em Inglês | MEDLINE | ID: mdl-31283898

RESUMO

Neuronal circuits that regulate movement are distributed throughout the nervous system. The brainstem is an important interface between upper motor centers involved in action planning and circuits in the spinal cord ultimately leading to execution of body movements. Here we focus on recent work using genetic and viral entry points to reveal the identity of functionally dedicated and frequently spatially intermingled brainstem populations essential for action diversification, a general principle conserved throughout evolution. Brainstem circuits with distinct organization and function control skilled forelimb behavior, orofacial movements, and locomotion. They convey regulatory parameters to motor output structures and collaborate in the construction of complex natural motor behaviors. Functionally tuned brainstem neurons for different actions serve as important integrators of synaptic inputs from upstream centers, including the basal ganglia and cortex, to regulate and modulate behavioral function in different contexts.


Assuntos
Tronco Encefálico/fisiologia , Neurônios Motores/fisiologia , Movimento/fisiologia , Medula Espinal/fisiologia , Animais , Humanos , Locomoção/fisiologia , Vias Neurais/fisiologia
10.
Proc Natl Acad Sci U S A ; 121(14): e2309000121, 2024 04 02.
Artigo em Inglês | MEDLINE | ID: mdl-38547067

RESUMO

Apneic events are frightening but largely benign events that often occur in infants. Here, we report apparent life-threatening apneic events in an infant with the homozygous SCN1AL263V missense mutation, which causes familial hemiplegic migraine type 3 in heterozygous family members, in the absence of epilepsy. Observations consistent with the events in the infant were made in an Scn1aL263V knock-in mouse model, in which apnea was preceded by a large brainstem DC-shift, indicative of profound brainstem depolarization. The L263V mutation caused gain of NaV1.1 function effects in transfected HEK293 cells. Sodium channel blockade mitigated the gain-of-function characteristics, rescued lethal apnea in Scn1aL263V mice, and decreased the frequency of severe apneic events in the patient. Hence, this study shows that SCN1AL263V can cause life-threatening apneic events, which in a mouse model were caused by profound brainstem depolarization. In addition to being potentially relevant to sudden infant death syndrome pathophysiology, these data indicate that sodium channel blockers may be considered therapeutic for apneic events in patients with these and other gain-of-function SCN1A mutations.


Assuntos
Apneia , Mutação com Ganho de Função , Bloqueadores dos Canais de Sódio , Animais , Humanos , Camundongos , Apneia/tratamento farmacológico , Apneia/genética , Tronco Encefálico , Células HEK293 , Enxaqueca com Aura/genética , Canal de Sódio Disparado por Voltagem NAV1.1/genética , Bloqueadores dos Canais de Sódio/uso terapêutico , Lactente , Feminino
11.
Hum Mol Genet ; 33(19): 1648-1659, 2024 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-38981620

RESUMO

Hearing loss is the most common congenital sensory deficit worldwide and exhibits high genetic heterogeneity, making molecular diagnoses elusive for most individuals. Detecting novel mutations that contribute to hearing loss is crucial to providing accurate personalized diagnoses, tailored interventions, and improving prognosis. Copy number variants (CNVs) are structural mutations that are understudied, potential contributors to hearing loss. Here, we present the Abnormal Wobbly Gait (AWG) mouse, the first documented mutant exhibiting waltzer-like locomotor dysfunction, hyperactivity, circling behaviour, and profound deafness caused by a spontaneous CNV deletion in cadherin 23 (Cdh23). We were unable to identify the causative mutation through a conventional whole-genome sequencing (WGS) and variant detection pipeline, but instead found a linked variant in hexokinase 1 (Hk1) that was insufficient to recapitulate the AWG phenotype when introduced into C57BL/6J mice using CRISPR-Cas9. Investigating nearby deafness-associated genes revealed a pronounced downregulation of Cdh23 mRNA and a complete absence of full-length CDH23 protein, which is critical for the development and maintenance of inner ear hair cells, in whole head extracts from AWG neonates. Manual inspection of WGS read depth plots of the Cdh23 locus revealed a putative 10.4 kb genomic deletion of exons 11 and 12 that was validated by PCR and Sanger sequencing. This study underscores the imperative to refine variant detection strategies to permit identification of pathogenic CNVs easily missed by conventional variant calling to enhance diagnostic precision and ultimately improve clinical outcomes for individuals with genetically heterogenous disorders such as hearing loss.


Assuntos
Caderinas , Variações do Número de Cópias de DNA , Surdez , Animais , Variações do Número de Cópias de DNA/genética , Caderinas/genética , Camundongos , Surdez/genética , Doenças Vestibulares/genética , Humanos , Hexoquinase/genética , Modelos Animais de Doenças , Camundongos Endogâmicos C57BL , Sequenciamento Completo do Genoma , Fenótipo , Proteínas Relacionadas a Caderinas , Mutação
12.
J Neurosci ; 44(36)2024 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-39107057

RESUMO

An interoceptive homeostatic reflex monitors levels of CO2/H+ to maintain blood gas homeostasis and rapidly regulate tissue acid-base balance by driving lung ventilation and CO2 excretion-this CO2-evoked increase in respiration is the hypercapnic ventilatory reflex (HCVR). Retrotrapezoid nucleus (RTN) neurons provide crucial excitatory drive to downstream respiratory rhythm/pattern-generating circuits, and their activity is directly modulated by changes in CO2/H+ RTN neurons express GPR4 and TASK-2, global deletion of which abrogates CO2/H+ activation of RTN neurons and the HCVR. It has not been determined if the intrinsic pH sensitivity of these proton detectors is required for these effects. We used CRISPR/Cas9 genome editing to generate mice with mutations in either of two pH-sensing histidine residues in GPR4 to determine effects on RTN neuronal CO2/H+ sensitivity and the HCVR. In global GPR4(H81F) and GPR4(H167F) mice, CO2-stimulated breathing and CO2-induced RTN neuronal activation were strongly blunted, with no effect on hypoxia-stimulated breathing. In brainstem slices from GPR4(H81F) mice, peak firing of RTN neurons during bath acidification was significantly reduced compared with GPR4 wild-type mice, and a subpopulation of RTN neurons was rendered pH-insensitive, phenocopying previous results from GPR4-deleted mice. These effects were independent of changes in RTN number/distribution, neuronal excitability or transcript levels for GPR4 and TASK-2. CO2-stimulated breathing was reduced to a similar extent in GPR4(H81F) and TASK-2-deleted mice, with combined mutation yielding no additional deficit in the HCVR. Together, these data demonstrate that the intrinsic pH sensitivity of GPR4 is necessary for full elaboration of the HCVR.


Assuntos
Dióxido de Carbono , Neurônios , Receptores Acoplados a Proteínas G , Animais , Receptores Acoplados a Proteínas G/genética , Receptores Acoplados a Proteínas G/metabolismo , Camundongos , Dióxido de Carbono/farmacologia , Dióxido de Carbono/metabolismo , Neurônios/metabolismo , Prótons , Respiração/efeitos dos fármacos , Masculino , Hipercapnia/metabolismo , Hipercapnia/fisiopatologia , Concentração de Íons de Hidrogênio , Camundongos Endogâmicos C57BL , Feminino , Camundongos Transgênicos , Canais de Potássio de Domínios Poros em Tandem/genética , Canais de Potássio de Domínios Poros em Tandem/metabolismo
13.
J Neurosci ; 44(26)2024 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-38664013

RESUMO

The periaqueductal gray (PAG) is a small midbrain structure that surrounds the cerebral aqueduct, regulates brain-body communication, and is often studied for its role in "fight-or-flight" and "freezing" responses to threat. We used ultra-high-field 7 T fMRI to resolve the PAG in humans and distinguish it from the cerebral aqueduct, examining its in vivo function during a working memory task (N = 87). Both mild and moderate cognitive demands elicited spatially similar patterns of whole-brain blood oxygenation level-dependent (BOLD) response, and moderate cognitive demand elicited widespread BOLD increases above baseline in the brainstem. Notably, these brainstem increases were not significantly greater than those in the mild demand condition, suggesting that a subthreshold brainstem BOLD increase occurred for mild cognitive demand as well. Subject-specific masks were group aligned to examine PAG response. In PAG, both mild and moderate demands elicited a well-defined response in ventrolateral PAG, a region thought to be functionally related to anticipated painful threat in humans and nonhuman animals-yet, the present task posed only the most minimal (if any) "threat," with the cognitive tasks used being approximately as challenging as remembering a phone number. These findings suggest that the PAG may play a more general role in visceromotor regulation, even in the absence of threat.


Assuntos
Imageamento por Ressonância Magnética , Memória de Curto Prazo , Substância Cinzenta Periaquedutal , Humanos , Substância Cinzenta Periaquedutal/fisiologia , Masculino , Feminino , Memória de Curto Prazo/fisiologia , Adulto , Imageamento por Ressonância Magnética/métodos , Adulto Jovem , Mapeamento Encefálico
14.
J Neurosci ; 44(22)2024 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-38604780

RESUMO

The autonomic nervous system (ANS) regulates the body's physiology, including cardiovascular function. As the ANS develops during the second to third trimester, fetal heart rate variability (HRV) increases while fetal heart rate (HR) decreases. In this way, fetal HR and HRV provide an index of fetal ANS development and future neurobehavioral regulation. Fetal HR and HRV have been associated with child language ability and psychomotor development behavior in toddlerhood. However, their associations with postbirth autonomic brain systems, such as the brainstem, hypothalamus, and dorsal anterior cingulate cortex (dACC), have yet to be investigated even though brain pathways involved in autonomic regulation are well established in older individuals. We assessed whether fetal HR and HRV were associated with the brainstem, hypothalamic, and dACC functional connectivity in newborns. Data were obtained from 60 pregnant individuals (ages 14-42) at 24-27 and 34-37 weeks of gestation using a fetal actocardiograph to generate fetal HR and HRV. During natural sleep, their infants (38 males and 22 females) underwent a fMRI scan between 40 and 46 weeks of postmenstrual age. Our findings relate fetal heart indices to brainstem, hypothalamic, and dACC connectivity and reveal connections with widespread brain regions that may support behavioral and emotional regulation. We demonstrated the basic physiologic association between fetal HR indices and lower- and higher-order brain regions involved in regulatory processes. This work provides the foundation for future behavioral or physiological regulation research in fetuses and infants.


Assuntos
Tronco Encefálico , Giro do Cíngulo , Frequência Cardíaca Fetal , Hipotálamo , Imageamento por Ressonância Magnética , Humanos , Feminino , Masculino , Giro do Cíngulo/fisiologia , Giro do Cíngulo/diagnóstico por imagem , Tronco Encefálico/diagnóstico por imagem , Tronco Encefálico/fisiologia , Recém-Nascido , Gravidez , Frequência Cardíaca Fetal/fisiologia , Adulto , Hipotálamo/fisiologia , Hipotálamo/diagnóstico por imagem , Hipotálamo/embriologia , Adolescente , Adulto Jovem , Mapeamento Encefálico/métodos , Vias Neurais/fisiologia
15.
Am J Hum Genet ; 109(5): 909-927, 2022 05 05.
Artigo em Inglês | MEDLINE | ID: mdl-35390279

RESUMO

Pontocerebellar hypoplasias (PCHs) are congenital disorders characterized by hypoplasia or early atrophy of the cerebellum and brainstem, leading to a very limited motor and cognitive development. Although over 20 genes have been shown to be mutated in PCHs, a large proportion of affected individuals remains undiagnosed. We describe four families with children presenting with severe neonatal brainstem dysfunction and pronounced deficits in cognitive and motor development associated with four different bi-allelic mutations in PRDM13, including homozygous truncating variants in the most severely affected individuals. Brain MRI and fetopathological examination revealed a PCH-like phenotype, associated with major hypoplasia of inferior olive nuclei and dysplasia of the dentate nucleus. Notably, histopathological examinations highlighted a sparse and disorganized Purkinje cell layer in the cerebellum. PRDM13 encodes a transcriptional repressor known to be critical for neuronal subtypes specification in the mouse retina and spinal cord but had not been implicated, so far, in hindbrain development. snRNA-seq data mining and in situ hybridization in humans show that PRDM13 is expressed at early stages in the progenitors of the cerebellar ventricular zone, which gives rise to cerebellar GABAergic neurons, including Purkinje cells. We also show that loss of function of prdm13 in zebrafish leads to a reduction in Purkinje cells numbers and a complete absence of the inferior olive nuclei. Altogether our data identified bi-allelic mutations in PRDM13 as causing a olivopontocerebellar hypoplasia syndrome and suggest that early deregulations of the transcriptional control of neuronal fate specification could contribute to a significant number of cases.


Assuntos
Encefalopatias , Peixe-Zebra , Animais , Encefalopatias/patologia , Tronco Encefálico , Cerebelo/anormalidades , Cerebelo/patologia , Deficiências do Desenvolvimento , Histona-Lisina N-Metiltransferase/genética , Humanos , Camundongos , Mutação/genética , Malformações do Sistema Nervoso , Neurogênese/genética , Células de Purkinje/metabolismo , Fatores de Transcrição/genética , Peixe-Zebra/metabolismo
16.
Brain ; 2024 Oct 24.
Artigo em Inglês | MEDLINE | ID: mdl-39445466

RESUMO

The role of radiosurgery in preventing haemorrhage in brainstem cavernous malformations remains a subject of debate. This study aims to evaluate whether radiosurgery provides a protective benefit against haemorrhage in these patients. This multicentre, prospective observational study was conducted in 17 centres and enrolled eligible patients with brainstem cavernous malformations consecutively. Data collected included clinical baseline information, radiosurgery planning details, periodic follow-up evaluations, and any adverse radiation effects. The primary outcome of the study was the incidence of first prospective haemorrhage, while the secondary outcome was the development of new or worsening neurological dysfunctions. The impact of radiosurgery was assessed using multivariate Cox regression analysis. From March 2016 to August 2018, the study enrolled 377 patients: 280 in the observation group receiving standard care alone and 97 in the radiosurgery group receiving both radiosurgery and standard care. The overall cohort consisted of 173 females (45.9%) with a mean age of 40.5 years (range, 18-68 years), and there were no significant differences in baseline characteristics between the two groups. After a median follow-up period of 70 months, haemorrhage occurred in 25.0% (n = 70) of patients in the observation group and 10.3% (n = 10) of patients in the radiosurgery group. Multivariate Cox regression analysis identified radiosurgery as an independent protective factor against haemorrhage (hazard ratio 0.379, 95% confidence interval 0.195-0.738, P = 0.004). Following 1:2 propensity score matching, the incidence of prospective haemorrhage were 24.9% (45/181) in the observation group compared to 10.3% (10/97) in the radiosurgery group (hazard ratio 0.379, 95% confidence interval 0.190-0.755, P = 0.006). Adverse radiation effects were observed in 12 patients (12.4%), with none were permanent. Additionally, new or worsening neurological dysfunctions were significantly more common in the observation group (28.9%) compared to the radiosurgery group (16.5%) (P = 0.016). These results suggest that radiosurgery is associated with a low rate of haemorrhage in patients with brainstem cavernous malformations and could provide a benefit in selected patients. However, further research is required to confirm these findings.

17.
Brain ; 2024 Oct 24.
Artigo em Inglês | MEDLINE | ID: mdl-39445741

RESUMO

The clinical manifestation of Parkinson's disease exhibits significant heterogeneity in the prevalence of non-motor symptoms and the rate of progression of motor symptoms, suggesting that Parkinson's disease can be classified into distinct subtypes. In this study, we aimed to explore this heterogeneity by identifying a set of subtypes with distinct patterns of spatiotemporal trajectories of neurodegeneration. We applied Subtype and Stage Inference (SuStaIn), an unsupervised machine learning algorithm that combined disease progression modelling with clustering methods, to cortical and subcortical neurodegeneration visible on 3 T structural MRI of a large cross-sectional sample of 504 patients and 279 healthy controls. Serial longitudinal data were available for a subset of 178 patients at the 2-year follow-up and for 140 patients at the 4-year follow-up. In a subset of 210 patients, concomitant Alzheimer's disease pathology was assessed by evaluating amyloid-ß concentrations in the CSF or via the amyloid-specific radiotracer 18F-flutemetamol with PET. The SuStaIn analysis revealed three distinct subtypes, each characterized by unique patterns of spatiotemporal evolution of brain atrophy: neocortical, limbic and brainstem. In the neocortical subtype, a reduction in brain volume occurred in the frontal and parietal cortices in the earliest disease stage and progressed across the entire neocortex during the early stage, although with relative sparing of the striatum, pallidum, accumbens area and brainstem. The limbic subtype represented comparative regional vulnerability, which was characterized by early volume loss in the amygdala, accumbens area, striatum and temporal cortex, subsequently spreading to the parietal and frontal cortices across disease stage. The brainstem subtype showed gradual rostral progression from the brainstem extending to the amygdala and hippocampus, followed by the temporal and other cortices. Longitudinal MRI data confirmed that 77.8% of participants at the 2-year follow-up and 84.0% at the 4-year follow-up were assigned to subtypes consistent with estimates from the cross-sectional data. This three-subtype model aligned with empirically proposed subtypes based on age at onset, because the neocortical subtype demonstrated characteristics similar to those found in the old-onset phenotype, including older onset and cognitive decline symptoms (P < 0.05). Moreover, the subtypes correspond to the three categories of the neuropathological consensus criteria for symptomatic patients with Lewy pathology, proposing neocortex-, limbic- and brainstem-predominant patterns as different subgroups of α-synuclein distributions. Among the subtypes, the prevalence of biomarker evidence of amyloid-ß pathology was comparable. Upon validation, the subtype model might be applied to individual cases, potentially serving as a biomarker to track disease progression and predict temporal evolution.

18.
Brain ; 2024 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-39375207

RESUMO

Post-mortem studies have shown that patients dying from severe acute respiratory syndrome coronavirus (SARS-CoV-2) infection frequently have pathological changes in their CNS, particularly in the brainstem. Many of these changes are proposed to result from para-infectious and/or post-infection immune responses. Clinical symptoms such as fatigue, breathlessness, and chest pain are frequently reported in post-hospitalized coronavirus disease 2019 (COVID-19) patients. We propose that these symptoms are in part due to damage to key neuromodulatory brainstem nuclei. While brainstem involvement has been demonstrated in the acute phase of the illness, the evidence of long-term brainstem change on MRI is inconclusive. We therefore used ultra-high field (7 T) quantitative susceptibility mapping (QSM) to test the hypothesis that brainstem abnormalities persist in post-COVID patients and that these are associated with persistence of key symptoms. We used 7 T QSM data from 30 patients, scanned 93-548 days after hospital admission for COVID-19 and compared them to 51 age-matched controls without prior history of COVID-19 infection. We correlated the patients' QSM signals with disease severity (duration of hospital admission and COVID-19 severity scale), inflammatory response during the acute illness (C-reactive protein, D-dimer and platelet levels), functional recovery (modified Rankin scale), depression (Patient Health Questionnaire-9) and anxiety (Generalized Anxiety Disorder-7). In COVID-19 survivors, the MR susceptibility increased in the medulla, pons and midbrain regions of the brainstem. Specifically, there was increased susceptibility in the inferior medullary reticular formation and the raphe pallidus and obscurus. In these regions, patients with higher tissue susceptibility had worse acute disease severity, higher acute inflammatory markers, and significantly worse functional recovery. This study contributes to understanding the long-term effects of COVID-19 and recovery. Using non-invasive ultra-high field 7 T MRI, we show evidence of brainstem pathophysiological changes associated with inflammatory processes in post-hospitalized COVID-19 survivors.

19.
Cereb Cortex ; 34(5)2024 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-38715405

RESUMO

OBJECTIVES: This retrospective study aimed to identify quantitative magnetic resonance imaging markers in the brainstem of preterm neonates with intraventricular hemorrhages. It delves into the intricate associations between quantitative brainstem magnetic resonance imaging metrics and neurodevelopmental outcomes in preterm infants with intraventricular hemorrhage, aiming to elucidate potential relationships and their clinical implications. MATERIALS AND METHODS: Neuroimaging was performed on preterm neonates with intraventricular hemorrhage using a multi-dynamic multi-echo sequence to determine T1 relaxation time, T2 relaxation time, and proton density in specific brainstem regions. Neonatal outcome scores were collected using the Bayley Scales of Infant and Toddler Development. Statistical analysis aimed to explore potential correlations between magnetic resonance imaging metrics and neurodevelopmental outcomes. RESULTS: Sixty preterm neonates (mean gestational age at birth 26.26 ± 2.69 wk; n = 24 [40%] females) were included. The T2 relaxation time of the midbrain exhibited significant positive correlations with cognitive (r = 0.538, P < 0.0001, Pearson's correlation), motor (r = 0.530, P < 0.0001), and language (r = 0.449, P = 0.0008) composite scores at 1 yr of age. CONCLUSION: Quantitative magnetic resonance imaging can provide valuable insights into neurodevelopmental outcomes after intraventricular hemorrhage, potentially aiding in identifying at-risk neonates. Multi-dynamic multi-echo sequence sequences hold promise as an adjunct to conventional sequences, enhancing the sensitivity of neonatal magnetic resonance neuroimaging and supporting clinical decision-making for these vulnerable patients.


Assuntos
Tronco Encefálico , Recém-Nascido Prematuro , Imageamento por Ressonância Magnética , Humanos , Masculino , Feminino , Imageamento por Ressonância Magnética/métodos , Recém-Nascido , Estudos Retrospectivos , Tronco Encefálico/diagnóstico por imagem , Tronco Encefálico/crescimento & desenvolvimento , Lactente , Hemorragia Cerebral Intraventricular/diagnóstico por imagem , Hemorragia Cerebral/diagnóstico por imagem , Transtornos do Neurodesenvolvimento/diagnóstico por imagem , Transtornos do Neurodesenvolvimento/etiologia , Idade Gestacional
20.
Cereb Cortex ; 34(1)2024 01 14.
Artigo em Inglês | MEDLINE | ID: mdl-37943791

RESUMO

Jhanas are profound states of mind achieved through advanced meditation, offering valuable insights into the nature of consciousness and tools to enhance well-being. Yet, its neurophenomenology remains limited due to methodological difficulties and the rarity of advanced meditation practitioners. We conducted a highly exploratory study to investigate the neurophenomenology of jhanas in an intensively sampled adept meditator case study (4 hr 7T fMRI collected in 27 sessions) who performed jhana meditation and rated specific aspects of experience immediately thereafter. Linear mixed models and correlations were used to examine relations among brain activity and jhana phenomenology. We identified distinctive patterns of brain activity in specific cortical, subcortical, brainstem, and cerebellar regions associated with jhana. Furthermore, we observed correlations between brain activity and phenomenological qualities of attention, jhanic qualities, and narrative processing, highlighting the distinct nature of jhanas compared to non-meditative states. Our study presents the most rigorous evidence yet that jhana practice deconstructs consciousness, offering unique insights into consciousness and significant implications for mental health and well-being.


Assuntos
Meditação , Humanos , Meditação/psicologia , Estado de Consciência , Atenção , Imageamento por Ressonância Magnética , Encéfalo/diagnóstico por imagem
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