Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 124.023
Filtrar
1.
Rev. neurol. (Ed. impr.) ; 78(7): 199-207, Ene-Jun, 2024. ilus, graf
Artículo en Español | IBECS | ID: ibc-232186

RESUMEN

Introducción: El neurocientífico español Justo Gonzalo y Rodríguez-Leal (1910-1986) investiga la organización funcional de la corteza cerebral durante más de cuatro décadas. Sus hallazgos le llevan a formular una teoría neurofisiológica basada en las leyes de la excitabilidad nerviosa, que denomina dinámica cerebral. En el presente trabajo se expone de forma cronológica cómo surgen las principales ideas sobre las que se articula.Desarrollo: En 1939 Gonzalo observa los denominados fenómenos de acción dinámica: desfasamiento, facilitación y repercusión cerebral. Le siguen dos principios: efecto cerebral de la lesión según la magnitud y posición (1941), y organización sensorial, según un desarrollo espiral (1947). Paralelamente, caracteriza lo que llama el síndrome central de la corteza cerebral. En la década de los cincuenta desarrolla los conceptos de gradiente cortical, similitud y alometría. En contraposición a las concepciones modulares de la corteza cerebral, en las que una región es responsable de una función, Gonzalo expresa que ‘los gradientes corticales dan la localización de los sistemas mientras la similitud y alometría revelan su trama funcional’.Conclusiones: La teoría de dinámica cerebral se articula en dos etapas. La primera (de 1938 a 1950) se caracteriza por una importante base clínica con observación de nuevos fenómenos y formulación de nuevos conceptos. La segunda (de 1950 a 1960) incluye la introducción de conceptos de mayor alcance, como el gradiente funcional cortical, y leyes de alometría que se basan en un cambio de escala. Actualmente, varios autores consideran que el concepto de gradiente es clave para entender la organización cerebral.(AU)


Introduction: The Spanish neuroscientist Justo Gonzalo y Rodríguez-Leal (1910-1986) investigated the functional organisation of the cerebral cortex over more than four decades. His findings led him to formulate a neurophysiological theory based on the laws of nervous excitability, which he called brain dynamics. This paper presents in chronological order how the main ideas on which it is based arose.Development: In 1939, Gonzalo observed the phenomena of dynamic action: asynchrony or disaggregation, facilitation and cerebral repercussion. This was followed by two principles: the cerebral effect of lesions according to their magnitude and position (1941), and spiral development of the sensory field (1947). At the same time, he characterised what he called the central syndrome of the cerebral cortex. In the 1950s he developed the concepts of the cortical gradient, similarity and allometry. In contrast to modular conceptions of the cerebral cortex, in which one region is responsible for one function, Gonzalo argued that ‘cortical gradients provide the location of systems, while similarity and allometry reveal their functional mechanism.’Conclusions: The theory of brain dynamics was established in two stages. The first (between 1938 and 1950) had an important clinical foundation, involving the observation of new phenomena and the formulation of new concepts. The second (between 1950 and 1960) included the introduction of more far-reaching concepts, such as the functional cortical gradient, and allometry laws based on a change of scale. Today, various authors believe that the concept of the gradient is crucial for understanding how the brain is organised.(AU)


Asunto(s)
Humanos , Masculino , Femenino , Corteza Cerebral , Corteza Cerebral/anatomía & histología , Neurología/historia , Cerebro/anatomía & histología , Neurofisiología
2.
Sci Rep ; 14(1): 8384, 2024 04 10.
Artículo en Inglés | MEDLINE | ID: mdl-38600114

RESUMEN

Spindle-shaped waves of oscillations emerge in EEG scalp recordings during human and rodent non-REM sleep. The association of these 10-16 Hz oscillations with events during prior wakefulness suggests a role in memory consolidation. Human and rodent depth electrodes in the brain record strong spindles throughout the cortex and hippocampus, with possible origins in the thalamus. However, the source and targets of the spindle oscillations from the hippocampus are unclear. Here, we employed an in vitro reconstruction of four subregions of the hippocampal formation with separate microfluidic tunnels for single axon communication between subregions assembled on top of a microelectrode array. We recorded spontaneous 400-1000 ms long spindle waves at 10-16 Hz in single axons passing between subregions as well as from individual neurons in those subregions. Spindles were nested within slow waves. The highest amplitudes and most frequent occurrence suggest origins in CA3 neurons that send feed-forward axons into CA1 and feedback axons into DG. Spindles had 50-70% slower conduction velocities than spikes and were not phase-locked to spikes suggesting that spindle mechanisms are independent of action potentials. Therefore, consolidation of declarative-cognitive memories in the hippocampus may be separate from the more easily accessible consolidation of memories related to thalamic motor function.


Asunto(s)
Hipocampo , Tálamo , Humanos , Hipocampo/fisiología , Tálamo/fisiología , Corteza Cerebral/fisiología , Axones , Neuronas , Electroencefalografía , Sueño/fisiología
3.
Nat Commun ; 15(1): 3511, 2024 Apr 25.
Artículo en Inglés | MEDLINE | ID: mdl-38664387

RESUMEN

Human cortical maturation has been posited to be organized along the sensorimotor-association axis, a hierarchical axis of brain organization that spans from unimodal sensorimotor cortices to transmodal association cortices. Here, we investigate the hypothesis that the development of functional connectivity during childhood through adolescence conforms to the cortical hierarchy defined by the sensorimotor-association axis. We tested this pre-registered hypothesis in four large-scale, independent datasets (total n = 3355; ages 5-23 years): the Philadelphia Neurodevelopmental Cohort (n = 1207), Nathan Kline Institute-Rockland Sample (n = 397), Human Connectome Project: Development (n = 625), and Healthy Brain Network (n = 1126). Across datasets, the development of functional connectivity systematically varied along the sensorimotor-association axis. Connectivity in sensorimotor regions increased, whereas connectivity in association cortices declined, refining and reinforcing the cortical hierarchy. These consistent and generalizable results establish that the sensorimotor-association axis of cortical organization encodes the dominant pattern of functional connectivity development.


Asunto(s)
Conectoma , Imagen por Resonancia Magnética , Corteza Sensoriomotora , Humanos , Adolescente , Femenino , Masculino , Adulto Joven , Niño , Corteza Sensoriomotora/fisiología , Corteza Sensoriomotora/diagnóstico por imagen , Preescolar , Red Nerviosa/fisiología , Red Nerviosa/diagnóstico por imagen , Vías Nerviosas/fisiología , Adulto , Corteza Cerebral/diagnóstico por imagen , Corteza Cerebral/fisiología , Corteza Cerebral/crecimiento & desarrollo
4.
Nat Commun ; 15(1): 3526, 2024 Apr 25.
Artículo en Inglés | MEDLINE | ID: mdl-38664419

RESUMEN

Large-scale imaging of brain activity with high spatio-temporal resolution is crucial for advancing our understanding of brain function. The existing neuroimaging techniques are largely limited by restricted field of view, slow imaging speed, or otherwise do not have the adequate spatial resolution to capture brain activities on a capillary and cellular level. To address these limitations, we introduce fluorescence localization microscopy aided with sparsely-labeled red blood cells for cortex-wide morphological and functional cerebral angiography with 4.9 µm spatial resolution and 1 s temporal resolution. When combined with fluorescence calcium imaging, the proposed method enables extended recordings of stimulus-evoked neuro-vascular changes in the murine brain while providing simultaneous multiparametric readings of intracellular neuronal activity, blood flow velocity/direction/volume, and vessel diameter. Owing to its simplicity and versatility, the proposed approach will become an invaluable tool for deciphering the regulation of cortical microcirculation and neurovascular coupling in health and disease.


Asunto(s)
Eritrocitos , Microscopía Fluorescente , Animales , Eritrocitos/metabolismo , Eritrocitos/citología , Microscopía Fluorescente/métodos , Ratones , Corteza Cerebral/irrigación sanguínea , Corteza Cerebral/diagnóstico por imagen , Corteza Cerebral/metabolismo , Masculino , Ratones Endogámicos C57BL , Angiografía Cerebral/métodos , Calcio/metabolismo , Circulación Cerebrovascular/fisiología , Colorantes Fluorescentes/química , Acoplamiento Neurovascular/fisiología , Neuronas/metabolismo , Neuronas/fisiología , Microcirculación
5.
Hum Brain Mapp ; 45(6): e26643, 2024 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-38664992

RESUMEN

Coping with distracting inputs during goal-directed behavior is a common challenge, especially when stopping ongoing responses. The neural basis for this remains debated. Our study explores this using a conflict-modulation Stop Signal task, integrating group independent component analysis (group-ICA), multivariate pattern analysis (MVPA), and EEG source localization analysis. Consistent with previous findings, we show that stopping performance is better in congruent (nonconflicting) trials than in incongruent (conflicting) trials. Conflict effects in incongruent trials compromise stopping more due to the need for the reconfiguration of stimulus-response (S-R) mappings. These cognitive dynamics are reflected by four independent neural activity patterns (ICA), each coding representational content (MVPA). It is shown that each component was equally important in predicting behavioral outcomes. The data support an emerging idea that perception-action integration in action-stopping involves multiple independent neural activity patterns. One pattern relates to the precuneus (BA 7) and is involved in attention and early S-R processes. Of note, three other independent neural activity patterns were associated with the insular cortex (BA13) in distinct time windows. These patterns reflect a role in early attentional selection but also show the reiterated processing of representational content relevant for stopping in different S-R mapping contexts. Moreover, the insular cortex's role in automatic versus complex response selection in relation to stopping processes is shown. Overall, the insular cortex is depicted as a brain hub, crucial for response selection and cancellation across both straightforward (automatic) and complex (conditional) S-R mappings, providing a neural basis for general cognitive accounts on action control.


Asunto(s)
Conflicto Psicológico , Electroencefalografía , Inhibición Psicológica , Corteza Insular , Humanos , Masculino , Femenino , Adulto , Adulto Joven , Corteza Insular/fisiología , Corteza Insular/diagnóstico por imagen , Mapeo Encefálico , Atención/fisiología , Desempeño Psicomotor/fisiología , Corteza Cerebral/fisiología , Corteza Cerebral/diagnóstico por imagen
6.
BMC Psychiatry ; 24(1): 281, 2024 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-38622613

RESUMEN

BACKGROUND: Violence in schizophrenia (SCZ) is a phenomenon associated with neurobiological factors. However, the neural mechanisms of violence in patients with SCZ are not yet sufficiently understood. Thus, this study aimed to explore the structural changes associated with the high risk of violence and its association with impulsiveness in patients with SCZ to reveal the possible neurobiological basis. METHOD: The voxel-based morphometry approach and whole-brain analyses were used to measure the alteration of gray matter volume (GMV) for 45 schizophrenia patients with violence (VSC), 45 schizophrenia patients without violence (NSC), and 53 healthy controls (HC). Correlation analyses were used to examine the association of impulsiveness and brain regions associated with violence. RESULTS: The results demonstrated reduced GMV in the right insula within the VSC group compared with the NSC group, and decreased GMV in the right temporal pole and left orbital part of superior frontal gyrus only in the VSC group compared to the HC group. Spearman correlation analyses further revealed a positive correlation between impulsiveness and GMV of the left superior temporal gyrus, bilateral insula and left medial orbital part of the superior frontal gyrus in the VSC group. CONCLUSION: Our findings have provided further evidence for structural alterations in patients with SCZ who had engaged in severe violence, as well as the relationship between the specific brain alterations and impulsiveness. This work provides neural biomarkers and improves our insight into the neural underpinnings of violence in patients with SCZ.


Asunto(s)
Esquizofrenia , Humanos , Masculino , Esquizofrenia/diagnóstico por imagen , Encéfalo/diagnóstico por imagen , Sustancia Gris/diagnóstico por imagen , Corteza Prefrontal , Corteza Cerebral/diagnóstico por imagen , Imagen por Resonancia Magnética/métodos
7.
Alzheimers Res Ther ; 16(1): 85, 2024 Apr 19.
Artículo en Inglés | MEDLINE | ID: mdl-38641653

RESUMEN

BACKGROUND: Dementia with Lewy bodies (DLB) is characterized by insular atrophy, which occurs at the early stage of the disease. Damage to the insula has been associated with disorders reflecting impairments of the most fundamental components of the self, such as anosognosia, which is a frequently reported symptom in patients with Lewy bodies (LB). The purpose of this study was to investigate modifications of the self-concept (SC), another component of the self, and to identify neuroanatomical correlates, in prodromal to mild DLB. METHODS: Twenty patients with prodromal to mild DLB were selected to participate in this exploratory study along with 20 healthy control subjects matched in terms of age, gender, and level of education. The Twenty Statements Test (TST) was used to assess the SC. Behavioral performances were compared between LB patients and control subjects. Three-dimensional magnetic resonance images (MRI) were acquired for all participants and correlational analyses were performed using voxel-based morphometry (VBM) in whole brain and using a mask for the insula. RESULTS: The behavioral results on the TST showed significantly impaired performances in LB patients in comparison with control subjects (p < .0001). Correlational analyses using VBM revealed positive correlations between the TST and grey matter volume within insular cortex, right supplementary motor area, bilateral inferior temporal gyri, right inferior frontal gyrus, and left lingual gyrus, using a threshold of p = .001 uncorrected, including total intracranial volume (TIV), age, and MMSE as nuisance covariates. Additionally, correlational analysis using a mask for the insula revealed positive correlation with grey matter volume within bilateral insular cortex, using a threshold of p = .005. CONCLUSIONS: The behavioral results confirm the existence of SC impairments in LB patients from the prodromal stage of the disease, compared to matched healthy controls. As we expected, VBM analyses revealed involvement of the insula, among that of other brain regions, already known to be involved in other self-components. While this study is exploratory, our findings provide important insights regarding the involvement of the insula within the self, confirming the insula as a core region of the self-networks, including for high-order self-representations such as the SC.


Asunto(s)
Enfermedad por Cuerpos de Lewy , Humanos , Enfermedad por Cuerpos de Lewy/diagnóstico por imagen , Enfermedad por Cuerpos de Lewy/patología , Corteza Insular , Encéfalo/patología , Corteza Cerebral/diagnóstico por imagen , Corteza Cerebral/patología , Sustancia Gris/diagnóstico por imagen , Sustancia Gris/patología , Imagen por Resonancia Magnética
8.
J Clin Neurosci ; 123: 157-161, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38579522

RESUMEN

BACKGROUND: This study aimed to assess abnormalities in the insular cortex of individuals suffering from migraines and examine their associations with pain duration, medication usage, and clinical symptoms. METHODS: We analyzed radiological data from 38 migraine patients who had undergone 3D iso T1-weighted brain MRI at our university hospital between 2019 and 2023. Structured questionnaires were used to collect information on participants' age, migraine type, disease duration, clinical symptoms, and medication use. Volumetric analysis was performed on the insular regions using Volbrain and 3DSlicer. The results were statistically analyzed. RESULTS: Comparing groups with chronic pain to normal groups revealed significant differences in several insular regions, including the posterior insula (p = 0.034), parietal operculum (p = 0.04), and the entire insular cortex (p = 0.023). Further group comparisons (Group 1, 2, and 3) showed significant differences in specific insular regions. For instance, the anterior insula (p = 0.032) was associated with taste changes, the posterior insula (p = 0.010) with smell-related changes, and the central operculum (p = 0.046) with sensations of nausea. Additionally, significant changes were observed in the parietal operculum concerning nausea, photophobia, phonophobia, and changes in smell. CONCLUSION: To the best of our knowledge, there have been no studies investigating the relationship between clinical manifestations and volumetric correlation. This study provides insights into abnormalities in the insular cortex among migraine patients and their potential relevance to pain duration, severity, and migraine type. The results suggest that understanding alterations in insular regions possibly linked to pain could contribute to the development of innovative approaches to managing chronic pain.


Asunto(s)
Dolor Crónico , Corteza Insular , Imagen por Resonancia Magnética , Trastornos Migrañosos , Humanos , Trastornos Migrañosos/diagnóstico por imagen , Femenino , Masculino , Adulto , Persona de Mediana Edad , Dolor Crónico/diagnóstico por imagen , Corteza Insular/diagnóstico por imagen , Adulto Joven , Corteza Cerebral/diagnóstico por imagen
9.
J Comp Neurol ; 532(4): e25615, 2024 04.
Artículo en Inglés | MEDLINE | ID: mdl-38587214

RESUMEN

The mammalian cerebrum has changed substantially during evolution, characterized by increases in neurons and glial cells and by the expansion and folding of the cerebrum. While these evolutionary alterations are thought to be crucial for acquiring higher cognitive functions, the molecular mechanisms underlying the development and evolution of the mammalian cerebrum remain only partially understood. This is, in part, because of the difficulty in analyzing these mechanisms using mice only. To overcome this limitation, genetic manipulation techniques for the cerebrum of gyrencephalic carnivore ferrets have been developed. Furthermore, successful gene knockout in the ferret cerebrum has been accomplished through the application of the CRISPR/Cas9 system. This review mainly highlights recent research conducted using gyrencephalic carnivore ferrets to investigate the mechanisms underlying the development and evolution of cortical folds.


Asunto(s)
Corteza Cerebral , Hurones , Animales , Ratones , Telencéfalo , Neuronas , Mamíferos
10.
Proc Natl Acad Sci U S A ; 121(16): e2317783121, 2024 Apr 16.
Artículo en Inglés | MEDLINE | ID: mdl-38588430

RESUMEN

GABAergic inhibitory interneurons, originating from the embryonic ventral forebrain territories, traverse a convoluted migratory path to reach the neocortex. These interneuron precursors undergo sequential phases of tangential and radial migration before settling into specific laminae during differentiation. Here, we show that the developmental trajectory of FoxG1 expression is dynamically controlled in these interneuron precursors at critical junctures of migration. By utilizing mouse genetic strategies, we elucidate the pivotal role of precise changes in FoxG1 expression levels during interneuron specification and migration. Our findings underscore the gene dosage-dependent function of FoxG1, aligning with clinical observations of FOXG1 haploinsufficiency and duplication in syndromic forms of autism spectrum disorders. In conclusion, our results reveal the finely tuned developmental clock governing cortical interneuron development, driven by temporal dynamics and the dose-dependent actions of FoxG1.


Asunto(s)
Corteza Cerebral , Neocórtex , Ratones , Animales , Corteza Cerebral/metabolismo , Movimiento Celular/fisiología , Neurogénesis/fisiología , Interneuronas/fisiología , Biomarcadores/metabolismo , Neuronas GABAérgicas/fisiología
11.
J Comp Neurol ; 532(4): e25612, 2024 04.
Artículo en Inglés | MEDLINE | ID: mdl-38591638

RESUMEN

Cellular-level anatomical data from early fetal brain are sparse yet critical to the understanding of neurodevelopmental disorders. We characterize the organization of the human cerebral cortex between 13 and 15 gestational weeks using high-resolution whole-brain histological data sets complimented with multimodal imaging. We observed the heretofore underrecognized, reproducible presence of infolds on the mesial surface of the cerebral hemispheres. Of note at this stage, when most of the cerebrum is occupied by lateral ventricles and the corpus callosum is incompletely developed, we postulate that these mesial infolds represent the primordial stage of cingulate, callosal, and calcarine sulci, features of mesial cortical development. Our observations are based on the multimodal approach and further include histological three-dimensional reconstruction that highlights the importance of the plane of sectioning. We describe the laminar organization of the developing cortical mantle, including these infolds from the marginal to ventricular zone, with Nissl, hematoxylin and eosin, and glial fibrillary acidic protein (GFAP) immunohistochemistry. Despite the absence of major sulci on the dorsal surface, the boundaries among the orbital, frontal, parietal, and occipital cortex were very well demarcated, primarily by the cytoarchitecture differences in the organization of the subplate (SP) and intermediate zone (IZ) in these locations. The parietal region has the thickest cortical plate (CP), SP, and IZ, whereas the orbital region shows the thinnest CP and reveals an extra cell-sparse layer above the bilaminar SP. The subcortical structures show intensely GFAP-immunolabeled soma, absent in the cerebral mantle. Our findings establish a normative neurodevelopment baseline at the early stage.


Asunto(s)
Encéfalo , Corteza Cerebral , Humanos , Cuerpo Calloso , Neuronas , Cabeza
12.
Cell Rep ; 43(4): 114059, 2024 Apr 23.
Artículo en Inglés | MEDLINE | ID: mdl-38602873

RESUMEN

Thalamocortical loops have a central role in cognition and motor control, but precisely how they contribute to these processes is unclear. Recent studies showing evidence of plasticity in thalamocortical synapses indicate a role for the thalamus in shaping cortical dynamics through learning. Since signals undergo a compression from the cortex to the thalamus, we hypothesized that the computational role of the thalamus depends critically on the structure of corticothalamic connectivity. To test this, we identified the optimal corticothalamic structure that promotes biologically plausible learning in thalamocortical synapses. We found that corticothalamic projections specialized to communicate an efference copy of the cortical output benefit motor control, while communicating the modes of highest variance is optimal for working memory tasks. We analyzed neural recordings from mice performing grasping and delayed discrimination tasks and found corticothalamic communication consistent with these predictions. These results suggest that the thalamus orchestrates cortical dynamics in a functionally precise manner through structured connectivity.


Asunto(s)
Aprendizaje , Tálamo , Tálamo/fisiología , Animales , Ratones , Aprendizaje/fisiología , Corteza Cerebral/fisiología , Memoria a Corto Plazo/fisiología , Vías Nerviosas/fisiología , Sinapsis/fisiología , Ratones Endogámicos C57BL , Masculino
13.
J Comp Neurol ; 532(4): e25611, 2024 04.
Artículo en Inglés | MEDLINE | ID: mdl-38625816

RESUMEN

A core component of the avian pallial cognitive network is the multimodal nidopallium caudolaterale (NCL) that is considered to be analogous to the mammalian prefrontal cortex (PFC). The NCL plays a key role in a multitude of executive tasks such as working memory, decision-making during navigation, and extinction learning in complex learning environments. Like the PFC, the NCL is positioned at the transition from ascending sensory to descending motor systems. For the latter, it sends descending premotor projections to the intermediate arcopallium (AI) and the medial striatum (MSt). To gain detailed insight into the organization of these projections, we conducted several retrograde and anterograde tracing experiments. First, we tested whether NCL neurons projecting to AI (NCLarco neurons) and MSt (NCLMSt neurons) are constituted by a single neuronal population with bifurcating neurons, or whether they form two distinct populations. Here, we found two distinct projection patterns to both target areas that were associated with different morphologies. Second, we revealed a weak topographic projection toward the medial and lateral striatum and a strong topographic projection toward AI with clearly distinguishable sensory termination fields. Third, we investigated the relationship between the descending NCL pathways to the arcopallium with those from the hyperpallium apicale, which harbors a second major descending pathway of the avian pallium. We embed our findings within a system of parallel pallio-motor loops that carry information from separate sensory modalities to different subpallial systems. Our results also provide insights into the evolution of the avian motor system from which, possibly, the song system has emerged.


Asunto(s)
Encéfalo , Columbidae , Animales , Columbidae/fisiología , Corteza Cerebral/fisiología , Cuerpo Estriado , Neostriado/fisiología , Mamíferos
14.
J Comp Neurol ; 532(4): e25616, 2024 04.
Artículo en Inglés | MEDLINE | ID: mdl-38634526

RESUMEN

Like the cerebralcortex, the surface of the cerebellum is repeatedly folded. Unlike the cerebralcortex, however, cerebellar folds are much thinner and more numerous; repeatthemselves largely along a single direction, forming accordion-like folds transverseto the mid-sagittal plane; and occur in all but the smallest cerebella. We haveshown previously that while the location of folds in mammalian cerebral cortex isclade-specific, the overall degree of folding strictly follows a universalpower law relating cortical thickness and the exposed and total surface areas predictedfrom the minimization of the effective free energy of an expanding, self-avoidingsurface of a certain thickness. Here we show that this scaling law extends tothe folding of the mid-sagittal sections of the cerebellum of 53 speciesbelonging to six mammalian clades. Simultaneously, we show that each clade hasa previously unsuspected distinctive spatial pattern of folding evident at themid-sagittal surface of the cerebellum. We note, however, that the mammaliancerebellum folds as a multi-fractal object, because of the difference betweenthe outside-in development of the cerebellar cortex around a preexisting coreof already connected white matter, compared to the inside-out development ofthe cerebral cortex with a white matter volume that develops as the cerebralcortex itself gains neurons. We conclude that repeated folding, one of the mostrecognizable features of biology, can arise simply from the interplay betweenthe universal applicability of the physics of self-organization and biological,phylogenetical clade-specific contingency, without the need for invokingselective pressures in evolution.


Asunto(s)
Cerebelo , Corteza Cerebral , Animales , Corteza Cerebral/fisiología , Mamíferos , Neuronas/fisiología , Corteza Cerebelosa
15.
Nat Commun ; 15(1): 3357, 2024 Apr 18.
Artículo en Inglés | MEDLINE | ID: mdl-38637493

RESUMEN

Egocentric encoding is a well-known property of brain areas along the dorsal pathway. Different to previous experiments, which typically only demanded egocentric spatial processing during movement preparation, we designed a task where two male rhesus monkeys memorized an on-the-object target position and then planned a reach to this position after the object re-occurred at variable location with potentially different size. We found allocentric (in addition to egocentric) encoding in the dorsal stream reach planning areas, parietal reach region and dorsal premotor cortex, which is invariant with respect to the position, and, remarkably, also the size of the object. The dynamic adjustment from predominantly allocentric encoding during visual memory to predominantly egocentric during reach planning in the same brain areas and often the same neurons, suggests that the prevailing frame of reference is less a question of brain area or processing stream, but more of the cognitive demands.


Asunto(s)
Corteza Cerebral , Percepción Espacial , Masculino , Animales , Percepción Espacial/fisiología , Corteza Cerebral/fisiología , Lóbulo Parietal/fisiología , Memoria , Cognición , Desempeño Psicomotor/fisiología
16.
Nat Commun ; 15(1): 3347, 2024 Apr 18.
Artículo en Inglés | MEDLINE | ID: mdl-38637553

RESUMEN

Neurons in the inferotemporal (IT) cortex respond selectively to complex visual features, implying their role in object perception. However, perception is subjective and cannot be read out from neural responses; thus, bridging the causal gap between neural activity and perception demands independent characterization of perception. Historically, though, the complexity of the perceptual alterations induced by artificial stimulation of IT cortex has rendered them impossible to quantify. To address this old problem, we tasked male macaque monkeys to detect and report optical impulses delivered to their IT cortex. Combining machine learning with high-throughput behavioral optogenetics, we generated complex and highly specific images that were hard for the animal to distinguish from the state of being cortically stimulated. These images, named "perceptograms" for the first time, reveal and depict the contents of the complex hallucinatory percepts induced by local neural perturbation in IT cortex. Furthermore, we found that the nature and magnitude of these hallucinations highly depend on concurrent visual input, stimulation location, and intensity. Objective characterization of stimulation-induced perceptual events opens the door to developing a mechanistic theory of visual perception. Further, it enables us to make better visual prosthetic devices and gain a greater understanding of visual hallucinations in mental disorders.


Asunto(s)
Lóbulo Temporal , Percepción Visual , Animales , Masculino , Humanos , Macaca mulatta/fisiología , Percepción Visual/fisiología , Lóbulo Temporal/fisiología , Corteza Cerebral/fisiología , Neuronas/fisiología , Estimulación Luminosa
17.
Cell Rep ; 43(4): 114027, 2024 Apr 23.
Artículo en Inglés | MEDLINE | ID: mdl-38568813

RESUMEN

The insular cortex is involved in diverse processes, including bodily homeostasis, emotions, and cognition. However, we lack a comprehensive understanding of how it processes information at the level of neuronal populations. We leveraged recent advances in unsupervised machine learning to study insular cortex population activity patterns (i.e., neuronal manifold) in mice performing goal-directed behaviors. We find that the insular cortex activity manifold is remarkably consistent across different animals and under different motivational states. Activity dynamics within the neuronal manifold are highly stereotyped during rewarded trials, enabling robust prediction of single-trial outcomes across different mice and across various natural and artificial motivational states. Comparing goal-directed behavior with self-paced free consumption, we find that the stereotyped activity patterns reflect task-dependent goal-directed reward anticipation, and not licking, taste, or positive valence. These findings reveal a core computation in insular cortex that could explain its involvement in pathologies involving aberrant motivations.


Asunto(s)
Objetivos , Corteza Insular , Animales , Ratones , Corteza Insular/fisiología , Masculino , Motivación/fisiología , Recompensa , Ratones Endogámicos C57BL , Neuronas/fisiología , Conducta Animal/fisiología , Corteza Cerebral/fisiología
18.
Nat Commun ; 15(1): 3039, 2024 Apr 08.
Artículo en Inglés | MEDLINE | ID: mdl-38589390

RESUMEN

Astrocytes are a direct target of neuromodulators and can influence neuronal activity on broad spatial and temporal scales in response to a rise in cytosolic calcium. However, our knowledge about how astrocytes are recruited during different animal behaviors remains limited. To measure astrocyte activity calcium in vivo during normative behaviors, we utilize a high-resolution, long working distance multicore fiber optic imaging system that allows visualization of individual astrocyte calcium transients in the cerebral cortex of freely moving mice. We define the spatiotemporal dynamics of astrocyte calcium changes during diverse behaviors, ranging from sleep-wake cycles to the exploration of novel objects, showing that their activity is more variable and less synchronous than apparent in head-immobilized imaging conditions. In accordance with their molecular diversity, individual astrocytes often exhibit distinct thresholds and activity patterns during explorative behaviors, allowing temporal encoding across the astrocyte network. Astrocyte calcium events were induced by noradrenergic and cholinergic systems and modulated by internal state. The distinct activity patterns exhibited by astrocytes provides a means to vary their neuromodulatory influence in different behavioral contexts and internal states.


Asunto(s)
Astrocitos , Calcio , Ratones , Animales , Astrocitos/metabolismo , Calcio/metabolismo , Neuronas/metabolismo , Diagnóstico por Imagen , Corteza Cerebral/metabolismo , Señalización del Calcio/fisiología
19.
Neurosci Lett ; 829: 137768, 2024 Apr 23.
Artículo en Inglés | MEDLINE | ID: mdl-38604300

RESUMEN

BACKGROUND: Aggression outcome expectation is an important cognitive factor of aggression. Discovering the neural mechanism of aggression outcome expectation is conducive to developing aggression research. However, the neural correlates underlying aggression outcome expectation and its effect remain elusive. METHODS: We utilized voxel-based morphometry (VBM) to unravel the neural architecture of aggression outcome expectation measured by the Social Emotional Information Processing Assessment for Adults and its relationship with aggression measured by the Buss Perry Aggression Questionnaire in a sample of 185 university students (114 female; mean age = 19.94 ± 1.62 years; age range: 17-32 years). RESULTS: We found a significantly positive correlation between aggression outcome expectation and the regional gray matter volume (GMV) in the right middle temporal gyrus (MTG) (x = 55.5, y = -58.5, z = 1.5; t = 3.35; cluster sizes = 352, p < 0.05, GRF corrected). Moreover, aggression outcome expectation acted as a mediator underlying the association between the right MTG volume and aggression. CONCLUSIONS: These results revealed the neural correlates of aggression outcome expectation and its effect on aggression for the first time, which may contribute to our understanding of the cognitive neural mechanism of aggression and potentially identifying neurobiological markers for aggression.


Asunto(s)
Agresión , Motivación , Adulto , Humanos , Femenino , Adolescente , Adulto Joven , Sustancia Gris/diagnóstico por imagen , Corteza Cerebral , Lóbulo Temporal , Imagen por Resonancia Magnética/métodos , Encéfalo
20.
PLoS One ; 19(4): e0298349, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38635579

RESUMEN

The claustrum is an irregular and fine sheet of grey matter in the basolateral telencephalon present in almost all mammals. The claustrum has been the object of several studies using animal models and, more recently, in human beings using neuroimaging. One of the most extended cognitive processes attributed to the claustrum is the salience process, which is also related to the insular cortex. In the same way, studies with human subjects and functional magnetic resonance imaging have reported the coactivation of the claustrum/insular cortex in the integration of sensory signals. This coactivation has been reported in the left claustrum/insular cortex or in the right claustrum/insular cortex. The asymmetry has been reported in task studies and literature related to neurological disorders such as Alzheimer's disease and schizophrenia, relating the severity of delusions with the reduction in left claustral volume. We present a functional connectivity study of the claustrum. Resting-state functional and anatomical MRI data from 100 healthy subjects were analyzed; taken from the Human Connectome Project (HCP, NIH Blueprint: The Human Connectome Project), with 2x2x2 mm3 voxel resolution. We hypothesize that 1) the claustrum is a node involved in different brain networks, 2) the functional connectivity pattern of the claustrum is different from the insular cortex's pattern, and 3) the asymmetry is present in the claustrum's functional connectivity. Our findings include at least three brain networks related to the claustrum. We found functional connectivity between the claustrum, frontoparietal network, and the default mode network as a distinctive attribute. The functional connectivity between the right claustrum with the frontoparietal network and the dorsal attention network supports the hypothesis of claustral asymmetry. These findings provide functional evidence, suggesting that the claustrum is coupled with the frontoparietal network serving together to instantiate new task states by flexibly modulating and interacting with other control and processing networks.


Asunto(s)
Claustro , Conectoma , Animales , Humanos , Encéfalo , Sustancia Gris/patología , Corteza Cerebral/diagnóstico por imagen , Imagen por Resonancia Magnética , Mamíferos
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...