Neurology, Neurologie, Physiology, morphology, Physiologie, morphologie, Sciences biologiques et medicales, Biological and medical sciences, Sciences biologiques fondamentales et appliquees. Psychologie, Fundamental and applied biological sciences. Psychology, Vertebres: systeme nerveux et organes des sens, Vertebrates: nervous system and sense organs, Généralités. Modélisation. Méthodes, General aspects. Models. Methods, Catécholamine, Catecholamine, Catecolamina, Encéphale, Encephalon, Encéfalo, Neurotransmetteur, Neurotransmitter, Neurotransmisor, Système nerveux central, Central nervous system, Sistema nervioso central, Acétylcholine, Acetylcholine, Acetilcolina, Article synthèse, Review, Artículo síntesis, Corps strié, Corpus striatum, Cuerpo estriado, Dopamine, Dopamina, Neurone intermédiaire, Interneuron, Neurona intermediaria, Noyau gris central, Basal ganglion, Núcleo basal, Pharmacologie, Pharmacology, Farmacología, acetylcholine, basal ganglia, dopamine, interneuron, and medium spiny neuron

The basal ganglia occupy the core of the forebrain and consist of evolutionarily conserved motor nuclei that form recurrent circuits critical for motivation and motor planning. The striatum is the main input nucleus of the basal ganglia and a key neural substrate for procedural learning and memory. The vast majority of striatal neurons are spiny GABAergic projection neurons, which exhibit slow but temporally precise spiking in vivo. Contributing to this precision are several different types of interneurons that constitute only a small fraction of total neuron number but play a critical role in regulating striatal output. This review examines the cellular physiology and modulation of striatal neurons that give rise to their unique properties and function.

Neurology, Neurologie, Physiology, morphology, Physiologie, morphologie, Sciences biologiques et medicales, Biological and medical sciences, Sciences biologiques fondamentales et appliquees. Psychologie, Fundamental and applied biological sciences. Psychology, Vertebres: systeme nerveux et organes des sens, Vertebrates: nervous system and sense organs, Oreille et annexes. Voies et centres auditifs. Audition. Organe vocal. Phonation. Emissions sonores. Echolocation, Ear and associated structures. Auditory pathways and centers. Hearing. Vocal organ. Phonation. Sound production. Echolocation, Encéphale, Brain (vertebrata), Encéfalo, Système nerveux central, Central nervous system, Sistema nervioso central, Voie auditive, Auditory pathway, Vía auditiva, Appareil auditif, Organ of hearing, Aparato auditivo, Article synthèse, Review, Artículo síntesis, Développement embryonnaire, Embryonic development, Desarrollo embrionario, Développement, Development, Desarrollo, Noyau cochléaire, Cochlear nucleus, Núcleo coclear, Oreille interne, Inner ear, Oido interno, and Ganglion cochléaire

The neurons of the cochlear ganglion transmit acoustic information between the inner ear and the brain. These placodally derived neurons must produce a topographically precise pattern of connections in both the inner ear and the brain. In this review, we consider the current state of knowledge concerning the development of these neurons, their peripheral and central connections, and their influences on peripheral and central target cells. Relatively little is known about the cellular and molecular regulation of migration or the establishment of precise topographic connection to the hair cells or cochlear nucleus (CN) neurons. Studies of mice with neurotrophin deletions are beginning to yield increasing understanding of variations in ganglion cell survival and resulting innervation patterns, however. Finally, existing evidence suggests that while ganglion cells have little influence on the differentiation of their hair cell targets, quite the opposite is true in the brain. Ganglion cell innervation and synaptic activity are essential for normal development of neurons in the cochlear nucleus.

Neurology, Neurologie, Physiology, morphology, Physiologie, morphologie, Sciences biologiques et medicales, Biological and medical sciences, Sciences biologiques fondamentales et appliquees. Psychologie, Fundamental and applied biological sciences. Psychology, Vertebres: systeme nerveux et organes des sens, Vertebrates: nervous system and sense organs, Généralités. Modélisation. Méthodes, General aspects. Models. Methods, Encéphale, Brain (vertebrata), Encéfalo, Système nerveux central, Central nervous system, Sistema nervioso central, Antipsychotique, Antipsychotic, Antipsicótico, Article synthèse, Review, Artículo síntesis, Autorécepteur, Autoreceptor, Récepteur dopaminergique, Dopamine receptor, Receptor dopaminérgico, Toxicomanie, Drug addiction, Toxicomanía, Transmission dopaminergique, Dopaminergic transmission, Transmisión dopaminérgica, Voie dopaminergique, Dopaminergic pathway, Vía dopaminérgica, Voie mésolimbique, Mesolimbic pathway, Vía mesolímbica, Aire tegmentale ventrale, and Voie mésocorticolimbique

Neurology, Neurologie, Physiology, morphology, Physiologie, morphologie, Sciences biologiques et medicales, Biological and medical sciences, Sciences biologiques fondamentales et appliquees. Psychologie, Fundamental and applied biological sciences. Psychology, Vertebres: systeme nerveux et organes des sens, Vertebrates: nervous system and sense organs, Oeil et annexes. Voies et centres visuels. Vision, Eye and associated structures. Visual pathways and centers. Vision, Electrophysiologie, Electrophysiology, Electrofisiología, Encéphale, Brain (vertebrata), Encéfalo, Système nerveux central, Central nervous system, Sistema nervioso central, Article synthèse, Review, Artículo síntesis, Mode décharge, Discharge pattern, Forma descarga, Modèle, Models, Modelo, Mouvement oculaire saccadé, Saccadic eye movement, Movimiento ocular brusco, Neurone moteur, Motor neuron, Neurona motora, Noyau moteur oculaire, Oculomotor nucleus, Núcleo motor ocular, Topographie, Topography, Topografía, Tubercule quadrijumeau antérieur, Colliculus superior, Tubérculo cuadrigémino anterior, Voie motrice oculaire, Ocular motor pathway, and Vía motora ocular

Neurology, Neurologie, Physiology, morphology, Physiologie, morphologie, Sciences biologiques et medicales, Biological and medical sciences, Sciences biologiques fondamentales et appliquees. Psychologie, Fundamental and applied biological sciences. Psychology, Vertebres: systeme nerveux et organes des sens, Vertebrates: nervous system and sense organs, Oeil et annexes. Voies et centres visuels. Vision, Eye and associated structures. Visual pathways and centers. Vision, Article synthèse, Review, Articulo sintesis, Champ récepteur, Receptive field, Corps genouillé externe, Lateral geniculate body, Cortex cérébral, Cerebral cortex, Cortex visuel, Visual cortex, Electrophysiologie, Electrophysiology, Electrofisiologia, Encéphale, Brain (Vertebrata), Encefalo, Rétine, Retina, Système nerveux central, Central nervous system, Sistema nervioso central, Toit optique, Optic tectum, Voie visuelle, and Visual pathway

Neurology, Neurologie, Physiology, morphology, Physiologie, morphologie, Sciences biologiques et medicales, Biological and medical sciences, Sciences biologiques fondamentales et appliquees. Psychologie, Fundamental and applied biological sciences. Psychology, Vertebres: systeme nerveux et organes des sens, Vertebrates: nervous system and sense organs, Développement. Sénescence. Régénération. Transplantation, Development. Senescence. Regeneration. Transplantation, Encéphale, Encephalon, Encéfalo, Système nerveux central, Central nervous system, Sistema nervioso central, Article synthèse, Review, Artículo síntesis, Axone, Axon, Axón, Dendrite, Dendrita, Différenciation, Differentiation, Diferenciación, Développement, Development, Desarrollo, Hippocampe, Hippocampus, Hipocampo, In vitro, Morphogenèse, Morphogenesis, Morfogénesis, Neurone, Neuron, Neurona, Précoce, Early, Precoz, Système nerveux, Nervous system, Sistema nervioso, axon determinants, cultured hippocampal neurons, morphogenesis, neuronal polarization, and positive-feedback mechanisms

Differentiation of axons and dendrites is a critical step in neuronal development. Here we review the evidence that axon/dendrite formation during neuronal polarization depends on the intrinsic cytoplasmic asymmetry inherited by the postmitotic neuron, the exposure of the neuron to extracellular chemical factors, and the action of anisotropic mechanical forces imposed by the environment. To better delineate the functions of early signals among a myriad of cellular components that were shown to influence axon/dendrite formation, we discuss their functions by distinguishing their roles as determinants, mediators, or modulators and consider selective degradation of these components as a potential mechanism for axon/dendrite polarization. Finally, we examine whether these early events of axon/dendrite formation involve local autocatalytic activation and long-range inhibition, as postulated by Alan Turing for the morphogenesis of patterned biological structure.

Neurology, Neurologie, Physiology, morphology, Physiologie, morphologie, Sciences biologiques et medicales, Biological and medical sciences, Sciences biologiques fondamentales et appliquees. Psychologie, Fundamental and applied biological sciences. Psychology, Vertebres: systeme nerveux et organes des sens, Vertebrates: nervous system and sense organs, Appareil olfactif et olfaction. Appareil gustatif et gustation, Olfactory system and olfaction. Gustatory system and gustation, Développement. Sénescence. Régénération. Transplantation, Development. Senescence. Regeneration. Transplantation, Hippocampe, Hippocampus, Hipocampo, Homme, Human, Hombre, Système nerveux central, Central nervous system, Sistema nervioso central, Voie olfactive, Olfactory pathway, Vía olfatoria, Adulte, Adult, Adulto, Article synthèse, Review, Artículo síntesis, Bulbe olfactif, Olfactory bulb, Bulbo olfatorio, Développement, Development, Desarrollo, Encéphale, Encephalon, Encéfalo, Gyrus dentelé, Dentate gyrus, Circunvolución dentada, Plasticité synaptique, Synaptic plasticity, Plasticidad sináptica, Synapse, Sinapsis, Synaptogenèse, Synaptogenesis, Sinaptogénesis, activity-dependent synaptic formation, dentate gyrus, olfactory bulb, synapse development, and synaptic plasticity

Although the lifelong addition of new neurons to the olfactory bulb and dentate gyrus of mammalian brains is by now an accepted fact, the function of adult-generated neurons still largely remains a mystery. The ability of new neurons to form synapses with preexisting neurons without disrupting circuit function is central to the hypothesized role of adult neurogenesis as a substrate for learning and memory. With the development of several new genetic labeling and imaging techniques, the study of synapse development and integration of these new neurons into mature circuits both in vitro and in vivo is rapidly advancing our insight into their structural plasticity. Investigators' observation of synaptogenesis occurring in the adult brain is beginning to shed light on the flexibility that adult neurogenesis offers to mature circuits and the potential contribution of the transient plasticity that new neurons provide toward circuit refinement and adaptation to changing environmental demands.

Neurology, Neurologie, Physiology, morphology, Physiologie, morphologie, Sciences biologiques et medicales, Biological and medical sciences, Sciences biologiques fondamentales et appliquees. Psychologie, Fundamental and applied biological sciences. Psychology, Vertebres: systeme nerveux et organes des sens, Vertebrates: nervous system and sense organs, Développement. Sénescence. Régénération. Transplantation, Development. Senescence. Regeneration. Transplantation, Encéphale, Encephalon, Encéfalo, Système nerveux central, Central nervous system, Sistema nervioso central, Article synthèse, Review, Artículo síntesis, Cortex cérébral, Cerebral cortex, Corteza cerebral, Développement, Development, Desarrollo, Mort cellulaire, Cell death, Muerte celular, Neuromédiateur, Neuromediator, Neuromediador, Neuropeptide, Neuropéptido, Neurotransmetteur, Neurotransmitter, Neurotransmisor, Organisation en colonne, Column organization, Organización en columna, Plasticité, Plasticity, Plasticidad, Précoce, Early, Precoz, Réseau neuronal, Neural network, Red neuronal, MAP2, cell death, cerebral cortex, connectivity, cortical column, development, neuronal network, neuropeptides, neurotransmitters, and plasticity

The developing mammalian cerebral cortex contains a distinct class of cells, subplate neurons (SPns), that play an important role during early development. SPns are the first neurons to be generated in the cerebral cortex, they reside in the cortical white matter, and they are the first to mature physiologically. SPns receive thalamic and neuromodulatory inputs and project into the developing cortical plate, mostly to layer 4. Thus SPns form one of the first functional cortical circuits and are required to relay early oscillatory activity into the developing cortical plate. Pathophysiological impairment or removal of SPns profoundly affects functional cortical development. SPn removal in visual cortex prevents the maturation of thalamocortical synapses, the maturation of inhibition in layer 4, the development of orientation selective responses and the formation of ocular dominance columns. SPn removal also alters ocular dominance plasticity during the critical period. Therefore, SPns are a key regulator of cortical development and plasticity. SPns are vulnerable to injury during prenatal stages and might provide a crucial link between brain injury in development and later cognitive malfunction.

Neurology, Neurologie, Physiology, morphology, Physiologie, morphologie, Sciences biologiques et medicales, Biological and medical sciences, Sciences biologiques fondamentales et appliquees. Psychologie, Fundamental and applied biological sciences. Psychology, Vertebres: systeme nerveux et organes des sens, Vertebrates: nervous system and sense organs, Oreille et annexes. Voies et centres auditifs. Audition. Organe vocal. Phonation. Emissions sonores. Echolocation, Ear and associated structures. Auditory pathways and centers. Hearing. Vocal organ. Phonation. Sound production. Echolocation, Encéphale, Encephalon, Encéfalo, Mammalia, Système nerveux central, Central nervous system, Sistema nervioso central, Vertebrata, Article synthèse, Review, Artículo síntesis, Audition, Hearing, Audición, Communication, Comunicación, Cortex préfrontal, Prefrontal cortex, Corteza prefrontal, Emission sonore, Sound production, Emisión sonora, Lobe frontal, Frontal lobe, Lóbulo frontal, Lobe temporal, Temporal lobe, Lóbulo temporal, Perception, Percepción, Primates, Stimulus acoustique, Acoustic stimulus, Estímulo acústico, acoustic, communication, complex sounds, frontal lobe, prefrontal cortex, and temporal lobe

Over the past decade, renewed interest in the auditory system has resulted in a surge of anatomical and physiological research in the primate auditory cortex and its targets. Anatomical studies have delineated multiple areas in and around primary auditory cortex and demonstrated connectivity among these areas, as well as between these areas and the rest of the cortex, including prefrontal cortex. Physiological recordings of auditory neurons have found that species-specific vocalizations are useful in probing the selectivity and potential functions of acoustic neurons. A number of cortical regions contain neurons that are robustly responsive to vocalizations, and some auditory responsive neurons show more selectivity for vocalizations than for other complex sounds. Demonstration of selectivity for vocalizations has prompted the question of which features are encoded by higher-order auditory neurons. Results based on detailed studies of the structure of these vocalizations, as well as the tuning and information-coding properties of neurons sensitive to these vocalizations, have begun to provide answers to this question. In future studies, these and other methods may help to define the way in which cells, ensembles, and brain regions process communication sounds. Moreover, the discovery that several nonprimary auditory cortical regions may be multisensory and responsive to vocalizations with corresponding facial gestures may change the way in which we view the processing of communication information by the auditory system.

Pharmacology drugs, Pharmacologie, galénique, Toxicology, Toxicologie, Sciences biologiques et medicales, Biological and medical sciences, Sciences biologiques fondamentales et appliquees. Psychologie, Fundamental and applied biological sciences. Psychology, Vertebres: systeme nerveux et organes des sens, Vertebrates: nervous system and sense organs, Système nerveux central, Central nervous system, Neurotransmission centrale. Neuromodulation. Voies et récepteurs, Central neurotransmission. Neuromudulation. Pathways and receptors, Aminoacide excitateur, Excitatory aminoacid, Aminoácido excitador, Elément minéral, Inorganic element, Elemento inorgánico, Neurotransmetteur, Neurotransmitter, Neurotransmisor, Névroglie, Neuroglia, Système nerveux central, Central nervous system, Sistema nervioso central, Article synthèse, Review, Artículo síntesis, Astrocyte, Astrocito, Calcium, Calcio, Encéphale, Encephalon, Encéfalo, Glutamate, Glutamato, Homme, Human, Hombre, Pharmacologie, Pharmacology, Farmacología, Physiologie, Physiology, Fisiología, Récepteur couplé protéine G, G protein coupled receptor, Receptor acoplado proteína G, Ca2+, Gq GPCR, IP3R, glia, glutamate, and microdomain

A number of exciting findings have been made in astrocytes during the past 15 years that have led many researchers to redefine how the brain works. Astrocytes are now widely regarded as cells that propagate Ca2+ over long distances in response to stimulation, and, similar to neurons, release transmitters (called gliotransmitters) in a Ca2+-dependent manner to modulate a host of important brain functions. Although these discoveries have been very exciting, it is essential to place them in the proper context of the approaches used to obtain them to determine their relevance to brain physiology. This review revisits the key observations made in astrocytes that greatly impact how they are thought to regulate brain function, including the existence of widespread propagating intercellular Ca2+ waves, data suggesting that astrocytes signal to neurons through Ca2+-dependent release of glutamate, and evidence for the presence of vesicular machinery for the regulated exocytosis of gliotransmitters.

Neurology, Neurologie, Physiology, morphology, Physiologie, morphologie, Sciences biologiques et medicales, Biological and medical sciences, Sciences biologiques fondamentales et appliquees. Psychologie, Fundamental and applied biological sciences. Psychology, Vertebres: systeme nerveux et organes des sens, Vertebrates: nervous system and sense organs, Circulation cérébrale. Barrière hématoencéphalique. Plexus choroïde. Liquide céphalorachidien. Organe épendymaire. Méninges, Cerebral circulation. Blood-brain barrier. Choroid plexus. Cerebrospinal fluid. Circumventricular organ. Meninges, Arthropoda, Diptera, Drosophilidae, Encéphale, Encephalon, Encéfalo, Insecta, Invertebrata, Névroglie, Neuroglia, Système nerveux central, Central nervous system, Sistema nervioso central, Article synthèse, Review, Artículo síntesis, Astrocyte, Astrocito, Barrière hématoencéphalique, Blood brain barrier, Barrera hematoencefálica, Cellule endothéliale, Endothelial cell, Célula endotelial, Drosophila, Jonction cellulaire, Cell junction, Unión celular, Jonction étanche, Tight junction, Unión estanca, Neurone, Neuron, Neurona, astrocytes, endothelial cells, neurovascular unit, septate junctions, and tight junctions

The blood brain barrier (BBB) evolved to preserve the microenvironment of the highly excitable neuronal cells to allow for action potential generation and propagation. Intricate molecular interactions between two main cell types, the neurons and the glial cells, form the underlying basis of the critical functioning of the nervous system across species. In invertebrates, interactions between neurons and glial cells are central in establishing a functional BBB. However, in vertebrates, the BBB formation and function is coordinated by interactions between neurons, glial cells, and endothelial cells. Here we review the neuron-glial interaction-based blood barriers in invertebrates and vertebrates and provide an evolutionary perspective as to how a glial-barrier system in invertebrates evolved into an endothelial barrier system. We also summarize the clinical relevance of the BBB as this protective barrier becomes disadvantageous in the pharmacological treatment of various neurological disorders.

Neurology, Neurologie, Physiology, morphology, Physiologie, morphologie, Sciences biologiques et medicales, Biological and medical sciences, Sciences biologiques fondamentales et appliquees. Psychologie, Fundamental and applied biological sciences. Psychology, Vertebres: systeme nerveux et organes des sens, Vertebrates: nervous system and sense organs, Appareil olfactif et olfaction. Appareil gustatif et gustation, Olfactory system and olfaction. Gustatory system and gustation, Encéphale, Encephalon, Encéfalo, Perception, Percepción, Système nerveux central, Central nervous system, Sistema nervioso central, Voie olfactive, Olfactory pathway, Vía olfatoria, Article synthèse, Review, Artículo síntesis, Bulbe olfactif, Olfactory bulb, Bulbo olfatorio, Codage, Coding, Codificación, Olfaction, Olfación, Précoce, Early, Precoz, Segmentation, Segmentación, Lobe antennaire, antennal lobe, chemotopy, concentration, olfactory bulb, segmentation, synchrony, and temporal coding

Olfactory space has a higher dimensionality than does any other class of sensory stimuli, and the olfactory system receives input from an unusually large number of unique information channels. This suggests that aspects of olfactory processing may differ fundamentally from processing in other sensory modalities. This review summarizes current understanding of early events in olfactory processing. We focus on how odors are encoded by the activity of primary olfactory receptor neurons, how odor codes may be transformed in the olfactory bulb, and what relevance these codes may have for downstream neurons in higher brain centers. Recent findings in synaptic physiology, neural coding, and psychophysics are discussed, with reference to both vertebrate and insect model systems.

Neurology, Neurologie, Physiology, morphology, Physiologie, morphologie, Sciences biologiques et medicales, Biological and medical sciences, Sciences biologiques fondamentales et appliquees. Psychologie, Fundamental and applied biological sciences. Psychology, Vertebres: systeme nerveux et organes des sens, Vertebrates: nervous system and sense organs, Oeil et annexes. Voies et centres visuels. Vision, Eye and associated structures. Visual pathways and centers. Vision, Encéphale, Encephalon, Encéfalo, Système nerveux central, Central nervous system, Sistema nervioso central, Voie visuelle, Visual pathway, Vía visual, Algorithme, Algorithm, Algoritmo, Article synthèse, Review, Artículo síntesis, Attention visuelle, Visual attention, Atención visual, Contour, Contorno, Cortex visuel, Visual cortex, Corteza visual, Groupement stimulus, Stimulus grouping, Agrupamiento estímulo, Perception, Percepción, Vision, Visión, binding, contextual modulation, contour grouping, grandmother cell, visual attention, and visual cortex

A fundamental task of vision is to group the image elements that belong to one object and to segregate them from other objects and the background. This review provides a conceptual framework of how perceptual grouping may be implemented in the visual cortex. According to this framework, two mechanisms are responsible for perceptual grouping: base-grouping and incremental grouping. Base-groupings are coded by single neurons tuned to multiple features, like the combination of a color and an orientation. They are computed rapidly because they reflect the selectivity of feedforward connections. However, not all conceivable feature combinations are coded by dedicated neurons. Therefore, a second, flexible form of grouping is required called incremental grouping. Incremental grouping enhances the responses of neurons coding features that are bound in perception, but it takes more time than does base-grouping because it relies also on horizontal and feedback connections. The modulation of neuronal response strength during incremental grouping has a correlate in psychology because attention is directed to those features that are labeled by the enhanced neuronal response.

Neurology, Neurologie, Physiology, morphology, Physiologie, morphologie, Sciences biologiques et medicales, Biological and medical sciences, Sciences biologiques fondamentales et appliquees. Psychologie, Fundamental and applied biological sciences. Psychology, Vertebres: systeme nerveux et organes des sens, Vertebrates: nervous system and sense organs, Système nerveux central, Central nervous system, Neurotransmission centrale. Neuromodulation. Voies et récepteurs, Central neurotransmission. Neuromudulation. Pathways and receptors, Catécholamine, Catecholamine, Catecolamina, Encéphale, Encephalon, Encéfalo, Système nerveux central, Central nervous system, Sistema nervioso central, Article synthèse, Review, Artículo síntesis, Cortex cingulaire, Cingulate cortex, Corteza cingular, Cortex orbitofrontal, Orbitofrontal cortex, Corteza orbitofrontal, Locus coeruleus, Neuromodulation, Neuromodulación, Noradrénaline, Norepinephrine, Noradrenalina, Optimisation, Optimization, Optimización, Prise décision, Decision making, Toma decision, anterior cingulate cortex, decision making, neuromodulation, optimization, orbitofrontal cortex, and utility

Historically, the locus coeruleus-norepinephrine (LC-NE) system has been implicated in arousal, but recent findings suggest that this system plays a more complex and specific role in the control of behavior than investigators previously thought. We review neurophysiological and modeling studies in monkey that support a new theory of LC-NE function. LC neurons exhibit two modes of activity, phasic and tonic. Phasic LC activation is driven by the outcome of task-related decision processes and is proposed to facilitate ensuing behaviors and to help optimize task performance (exploitation). When utility in the task wanes, LC neurons exhibit a tonic activity mode, associated with disengagement from the current task and a search for alternative behaviors (exploration). Monkey LC receives prominent, direct inputs from the anterior cingulate (ACC) and orbitofrontal cortices (OFC), both of which are thought to monitor task-related utility. We propose that these frontal areas produce the above patterns of LC activity to optimize utility on both short and long timescales.

Neurology, Neurologie, Physiology, morphology, Physiologie, morphologie, Sciences biologiques et medicales, Biological and medical sciences, Sciences biologiques fondamentales et appliquees. Psychologie, Fundamental and applied biological sciences. Psychology, Vertebres: systeme nerveux et organes des sens, Vertebrates: nervous system and sense organs, Généralités. Modélisation. Méthodes, General aspects. Models. Methods, Encéphale, Encephalon, Encéfalo, Système nerveux central, Central nervous system, Sistema nervioso central, Article synthèse, Review, Artículo síntesis, Cortex cérébral, Cerebral cortex, Corteza cerebral, Modèle, Models, Modelo, Réseau neuronal, Neural network, Red neuronal, computation, excitation, inhibition, model, and network

We explore the extent to which neocortical circuits generalize, i.e., to what extent can neocortical neurons and the circuits they form be considered as canonical? We find that, as has long been suspected by cortical neuroanatomists, the same basic laminar and tangential organization of the excitatory neurons of the neocortex is evident wherever it has been sought. Similarly, the inhibitory neurons show characteristic morphology and patterns of connections throughout the neocortex. We offer a simple model of cortical processing that is consistent with the major features of cortical circuits: The superficial layer neurons within local patches of cortex, and within areas, cooperate to explore all possible interpretations of different cortical input and cooperatively select an interpretation consistent with their various cortical and subcortical inputs.

Neurology, Neurologie, Physiology, morphology, Physiologie, morphologie, Sciences biologiques et medicales, Biological and medical sciences, Sciences biologiques fondamentales et appliquees. Psychologie, Fundamental and applied biological sciences. Psychology, Vertebres: systeme nerveux et organes des sens, Vertebrates: nervous system and sense organs, Oeil et annexes. Voies et centres visuels. Vision, Eye and associated structures. Visual pathways and centers. Vision, Système nerveux central, Central nervous system, Sistema nervioso central, Voie visuelle, Visual pathway, Vía visual, Anatomie, Anatomy, Anatomía, Article synthèse, Review, Artículo síntesis, Cortex visuel, Visual cortex, Corteza visual, Encéphale, Encephalon, Encéfalo, cerebral cortex, cortical map, optimization, visual processing, and wiring economy

In mammalian visual cortex, neurons are organized according to their functional properties into multiple maps such as retinotopic, ocular dominance, orientation preference, direction of motion, and others. What determines the organization of cortical maps? We argue that cortical maps reflect neuronal connectivity in intracortical circuits. Because connecting distant neurons requires costly wiring (i.e., axons and dendrites), there is an evolutionary pressure to place connected neurons as close to each other as possible. Then, cortical maps may be viewed as solutions that minimize wiring cost for given intracortical connectivity. These solutions can help us in inferring intracortical connectivity and, ultimately, in understanding the function of the visual system.

Neurology, Neurologie, Physiology, morphology, Physiologie, morphologie, Sciences biologiques et medicales, Biological and medical sciences, Sciences biologiques fondamentales et appliquees. Psychologie, Fundamental and applied biological sciences. Psychology, Vertebres: systeme nerveux et organes des sens, Vertebrates: nervous system and sense organs, Système nerveux central, Central nervous system, Electrophysiologie, Electrophysiology, Système nerveux central, Central nervous system, Sistema nervioso central, Vertebrata, Article synthèse, Review, Artículo síntesis, Connexine, Connexin, Connexina, Encéphale, Encephalon, Encéfalo, Jonction communicante, Gap junction, Unión comunicante, Mammalia, Synapse, Sinapsis, connexin36, connexin, electrical coupling, electrotonic synapse, and gap junction

Many neurons in the mammalian central nervous system communicate through electrical synapses, defined here as gap junction-mediated connections. Electrical synapses are reciprocal pathways for ionic current and small organic molecules. They are often strong enough to mediate close synchronization of subthreshold and spiking activity among clusters of neurons. The most thoroughly studied electrical synapses occur between excitatory projection neurons of the inferior olivary nucleus and between inhibitory interneurons of the neocortex, hippocampus, and thalamus. All these synapses require the gap junction protein connexin36 (Cx36) for robust electrical coupling. Cx36 appears to interconnect neurons exclusively, and it is expressed widely along the mammalian neuraxis, implying that there are undiscovered electrical synapses throughout the central nervous system. Some central neurons may be electrically coupled by other connexin types or by pannexins, a newly described family of gap junction proteins. Electrical synapses are a ubiquitous yet underappreciated feature of neural circuits in the mammalian brain.

Neurology, Neurologie, Physiology, morphology, Physiologie, morphologie, Sciences biologiques et medicales, Biological and medical sciences, Sciences biologiques fondamentales et appliquees. Psychologie, Fundamental and applied biological sciences. Psychology, Vertebres: systeme nerveux et organes des sens, Vertebrates: nervous system and sense organs, Système nerveux central, Central nervous system, Electrophysiologie, Electrophysiology, Encéphale, Encephalon, Encéfalo, Jonction cellulaire, Cell junction, Unión celular, Système nerveux central, Central nervous system, Sistema nervioso central, Article synthèse, Review, Artículo síntesis, Electrophysiologie, Electrophysiology, Electrofisiología, Hippocampe, Hippocampus, Hipocampo, In vitro, Jonction communicante, Gap junction, Unión comunicante, Oscillation, Oscilación, Rythme gamma, Gamma rhythm, Ritmo γ, Rythme thêta, Theta rhythm, Ritmo θ, 40 Hz, gamma oscillation, gap junctions, ripple, and theta oscillation

A variety of population oscillations, at frequencies ∼5 Hz up to 200 Hz and above, can be induced in hippocampal slices either by (a) manipulation of the ionic environment, or (b) by stimulation of metabotropic receptors; brief oscillations can even occur spontaneously. In this review, we consider in vitro theta (4-12 Hz), gamma/beta (15-70 Hz), and very fast oscillations (VFO) (>70 Hz). Many in vitro oscillations are gated by synaptic inhibition but are influenced by electrical coupling as well; one type depends solely on electrical coupling. For some oscillations dependent upon inhibition, the detailed firing patterns of interneurons can influence long-range synchronization. Two sorts of electrical coupling are important in modulating or generating various in vitro oscillations: (a) between interneurons, primarily between dendrites; and (b) between axons of pyramidal neurons. VFO can exist in isolation or can act as generators of gamma frequency oscillations. Oscillations at gamma frequencies and below probably create conditions under which synaptic plasticity can occur, between selected neurons-even those separated by significant axonal conduction delays.

Neurology, Neurologie, Physiology, morphology, Physiologie, morphologie, Sciences biologiques et medicales, Biological and medical sciences, Sciences biologiques fondamentales et appliquees. Psychologie, Fundamental and applied biological sciences. Psychology, Vertebres: systeme nerveux et organes des sens, Vertebrates: nervous system and sense organs, Oeil et annexes. Voies et centres visuels. Vision, Eye and associated structures. Visual pathways and centers. Vision, Encéphale, Encephalon, Encéfalo, Mammalia, Primates, Système nerveux central, Central nervous system, Sistema nervioso central, Vertebrata, Voie visuelle, Visual pathway, Vía visual, Article synthèse, Review, Artículo síntesis, Attention visuelle, Visual attention, Atención visual, Cortex visuel, Visual cortex, Corteza visual, Electrophysiologie, Electrophysiology, Electrofisiología, Singe, Monkey, Mono, Traitement information, Information processing, Procesamiento información, contrast, feedback, limited capacity, macaque, and visual cortex

Single-unit recording studies in the macaque have carefully documented the modulatory effects of attention on the response properties of visual cortical neurons. Attention produces qualitatively different effects on firing rate, depending on whether a stimulus appears alone or accompanied by distracters. Studies of contrast gain control in anesthetized mammals have found parallel patterns of results when the luminance contrast of a stimulus increases. This finding suggests that attention has coopted the circuits that mediate contrast gain control and that it operates by increasing the effective contrast of the attended stimulus. Consistent with this idea, microstimulation of the frontal eye fields, one of several areas that control the allocation of spatial attention, induces spatially local increases in sensitivity both at the behavioral level and among neurons in area V4, where endogenously generated attention increases contrast sensitivity. Studies in the slice have begun to explain how modulatory signals might cause such increases in sensitivity.

Neurology, Neurologie, Physiology, morphology, Physiologie, morphologie, Sciences biologiques et medicales, Biological and medical sciences, Sciences biologiques fondamentales et appliquees. Psychologie, Fundamental and applied biological sciences. Psychology, Vertebres: systeme nerveux et organes des sens, Vertebrates: nervous system and sense organs, Motricité et voies motrices. Réflexes. Centres de contrôle des fonctions végétatives. Système vestibulaire et équilibration, Motor control and motor pathways. Reflexes. Control centers of vegetative functions. Vestibular system and equilibration, Neurotransmetteur, Neurotransmitter, Neurotransmisor, Système nerveux central, Central nervous system, Sistema nervioso central, Article synthèse, Review, Artículo síntesis, Chimiosensibilité, Chemosensitivity, Quimiosensibilidad, Contrôle respiratoire, Respiratory control, Control respiratorio, Encéphale, Brain (vertebrata), Encéfalo, Plasticité, Plasticity, Plasticidad, Respiration, Respiración, Rythme respiratoire, Breathing rate, Ritmo respiratorio, Sérotonine, Serotonin, Serotonina, neurokinin, pacemaker, preBötzinger, raphe, and serotonin

Breathing is a vital behavior that is particularly amenable to experimental investigation. We review recent progress on three problems of broad interest. (i) Where and how is respiratory rhythm generated? The preBötzinger Complex is a critical site, whereas pacemaker neurons may not be essential. The possibility that coupled oscillators are involved is considered. (ii) What are the mechanisms that underlie the plasticity necessary for adaptive changes in breathing? Serotonin-dependent long-term facilitation following intermittent hypoxia is an important example of such plasticity, and a model that can account for this adaptive behavior is discussed. (iii) Where and how are the regulated variables CO2 and pH sensed? These sensors are essential if breathing is to be appropriate for metabolism. Neurons with appropriate chemosensitivity are spread throughout the brainstem; their individual properties and collective role are just beginning to be understood.