Editorial overview: Cellular neuroscience.
PMID: 30017788 [PubMed - as supplied by publisher] (Source: Current Opinion in Neurobiology)
Source: Current Opinion in Neurobiology - July 13, 2018 Category: Neurology Authors: Holzbaur E, Burrone J Tags: Curr Opin Neurobiol Source Type: research

Synaptic plasticity in human cortical circuits: cellular mechanisms of learning and memory in the human brain?
Abstract Synaptic plasticity is the cellular basis of learning and memory, but to what extent this holds for the adult human brain is not known. To study synaptic plasticity in human neuronal circuits poses a huge challenge, since live human neurons and synapses are not readily accessible. Despite this, various lines of research have provided insights in properties of adult human synapses and their plasticity both in vitro and in vivo, with some unexpected surprises. We first discuss the experimental approaches to study activity-dependent plasticity of adult human synapses, and then highlight rules and mechanisms ...
Source: Current Opinion in Neurobiology - July 12, 2018 Category: Neurology Authors: Mansvelder HD, Verhoog MB, Goriounova NA Tags: Curr Opin Neurobiol Source Type: research

Developmental genetic programs and activity-dependent mechanisms instruct neocortical area mapping.
Abstract The subdivision of the mammalian neocortex into specialized modality-specific areas is responsible for the processing of sensory information followed by an adequate motor response. This process, called arealization, depends on the graded expression of transcription factors in neocortical progenitors and postmitotic neurons prenatally, and on external activity-dependent cues driven by thalamocortical axons during postnatal stages. Thalamic inputs are guided within an intrinsically determined genetic framework to selectively target and innervate layer 4 (L4) cortical neurons in a somatotopic manner. L4 spin...
Source: Current Opinion in Neurobiology - July 10, 2018 Category: Neurology Authors: Simi A, Studer M Tags: Curr Opin Neurobiol Source Type: research

Actin Assemblies in the Axon Shaft - some Open Questions.
Abstract The actin cytoskeleton in neurons plays critical roles in axonal growth and synaptic organization. Until recently, most studies on axonal actin were limited to terminal growth cones or synapses, whereas the organization of actin along the shaft of the axon was relatively ignored. However, experiments using super-resolution microscopy and live imaging have revealed previously unknown actin structures along the axonal shaft, such as periodic 'actin rings' circumferentially wrapping underneath the plasma membrane and dynamic actin pools deeper within the axon shaft (termed actin 'hotspots' and 'trails'). In ...
Source: Current Opinion in Neurobiology - July 10, 2018 Category: Neurology Authors: Dubey P, Jorgenson K, Roy S Tags: Curr Opin Neurobiol Source Type: research

Reciprocal amygdala-prefrontal interactions in learning.
Abstract Animals constantly evaluate their environment in order to avoid potential threats and obtain reward in the form of food, shelter and social interactions. In order to appropriately respond to sensory cues from the environment, the brain needs to form and store multiple cue-outcome associations. These can then be used to form predictions of the valence of sounds, smells and other sensory inputs arising from the surroundings. However, these associations must be subject to constant update, as the environment can rapidly change. Failing to adapt to such change can be detrimental to survival. Several systems in...
Source: Current Opinion in Neurobiology - July 2, 2018 Category: Neurology Authors: Yizhar O, Klavir O Tags: Curr Opin Neurobiol Source Type: research

Wnt proteins as modulators of synaptic plasticity.
Abstract Dynamic changes in the structure and function of synapses in response to the environment, termed synaptic plasticity, are the cellular basis of learning and memory. At excitatory synapses, activation of NMDA receptors by glutamate leads to calcium influx triggering intracellular pathways that promote the trafficking of AMPA receptors to the post-synaptic membrane and actin remodeling. New evidence shows that Wnt secreted proteins, known for their role in synapse development, are essential for early stages of long-term potentiation, a form of plasticity that increases synaptic strength. Here, we review rec...
Source: Current Opinion in Neurobiology - July 2, 2018 Category: Neurology Authors: McLeod F, Salinas PC Tags: Curr Opin Neurobiol Source Type: research

Development of vestibular behaviors in zebrafish.
Abstract Most animals orient their bodies with respect to gravity to facilitate locomotion and perception. The neural circuits responsible for these orienting movements have long served as a model to address fundamental questions in systems neuroscience. Though postural control is vital, we know little about development of either balance reflexes or the neural circuitry that produces them. Recent work in a genetically and optically accessible vertebrate, the larval zebrafish, has begun to reveal the mechanisms by which such vestibular behaviors and circuits come to function. Here we highlight recent work that leve...
Source: Current Opinion in Neurobiology - June 25, 2018 Category: Neurology Authors: Bagnall MW, Schoppik D Tags: Curr Opin Neurobiol Source Type: research

Deciphering Drosophila female innate behaviors.
Abstract Innate responses are often sexually dimorphic. Studies of female specific behaviors have remained niche, but the focus is changing as illustrated by the recent progress in understanding the female courtship responses and egg-laying decisions. In this review, we will cover our current knowledge about female behaviors in these two specific contexts. Recent studies elucidate on how females process the courtship song. They also show that egg-laying decisions are extremely complex, requiring the assessment of food, microbial, predator and social cues. Study of female responses will improve our understanding of...
Source: Current Opinion in Neurobiology - June 22, 2018 Category: Neurology Authors: Aranha MM, Vasconcelos ML Tags: Curr Opin Neurobiol Source Type: research

Cortical dendritic spine development and plasticity: insights from in vivo imaging.
Abstract Dendritic spines are the postsynaptic sites of most excitatory synapses in the cerebral cortex. Their morphology and density change throughout life, reflecting the maturation and reorganization of excitatory circuits. The development of in vivo two-photon microscopy has enabled the monitoring of the same dendritic spines over time during different developmental periods. In this review we focus on recent in vivo imaging studies in rodents that have revealed cell type-specific and region-specific structural dynamics of dendritic spines. We also discuss how the contributions of local inhibitory neurons and l...
Source: Current Opinion in Neurobiology - June 21, 2018 Category: Neurology Authors: Moyer CE, Zuo Y Tags: Curr Opin Neurobiol Source Type: research

Development of tactile sensory circuits in the CNS.
Abstract Molecular identification of neuronal types and genetic and imaging approaches to characterize their properties reveal morphological, physiological and dynamic aspects of sensory circuit development. Here we focus on the mouse tactile sensory circuitry, with particular emphasis on the main trigeminal pathway that connects the whiskers, the major tactile organ in rodents, to the neocortex. At each level of this pathway, neurogenesis, axonal elongation, pathfinding, target recognition and circuit reorganization including dendritic refinement of cortical layer 4 neurons occur contemporaneously and a multitude...
Source: Current Opinion in Neurobiology - June 13, 2018 Category: Neurology Authors: Iwasato T, Erzurumlu RS Tags: Curr Opin Neurobiol Source Type: research

Subsynaptic spatial organization as a regulator of synaptic strength and plasticity.
Abstract Synapses differ markedly in their performance, even amongst those on a single neuron. The mechanisms that drive this functional diversification are of great interest because they enable adaptive behaviors and are targets of pathology. Considerable effort has focused on elucidating mechanisms of plasticity that involve changes to presynaptic release probability and the number of postsynaptic receptors. However, recent work is clarifying that nanoscale organization of the proteins within glutamatergic synapses impacts synapse function. Specifically, active zone scaffold proteins form nanoclusters that defin...
Source: Current Opinion in Neurobiology - June 11, 2018 Category: Neurology Authors: Chen H, Tang AH, Blanpied TA Tags: Curr Opin Neurobiol Source Type: research

Transcriptional control of long-range cortical projections.
ds LJ Abstract Long-range projection neurons of the neocortex form the major tracts of the mammalian brain and are crucial for sensory-motor, associative and executive functions. Development of such circuits involves neuronal proliferation, specification and migration, as well as axonal elongation, navigation and targeting, where growing axons encounter multiple guidance cues and integrate these signals to execute guidance decisions. The complexity of axon guidance mechanisms in the formation of long-range neuronal projections has suggested that they might be under control of transcription factors, which are DNA-b...
Source: Current Opinion in Neurobiology - June 9, 2018 Category: Neurology Authors: Paolino A, Fenlon LR, Suárez R, Richards LJ Tags: Curr Opin Neurobiol Source Type: research

Synergistic control of neurotransmitter release by different members of the synaptotagmin family.
Abstract Quantal neurotransmitter release at nerve terminals is tightly regulated by the presynaptic Ca2+ concentration. Here, we summarise current advances in understanding how the interplay between presynaptic Ca2+ dynamics and different Ca2+ release sensors shapes action potential-evoked release on a timescale from hundreds of microseconds to hundreds of milliseconds. In particular, we review recent studies that reveal the synergistic roles of the low Ca2+ affinity/fast release sensors synaptotagmins 1, 2 and 9 and the high affinity/slow release sensor synaptotagmin 7 in the regulation of synchronous and asynch...
Source: Current Opinion in Neurobiology - June 7, 2018 Category: Neurology Authors: Volynski KE, Krishnakumar SS Tags: Curr Opin Neurobiol Source Type: research

Contextual signals in visual cortex.
Abstract Vision is an active process. What we perceive strongly depends on our actions, intentions and expectations. During visual processing, these internal signals therefore need to be integrated with the visual information from the retina. The mechanisms of how this is achieved by the visual system are still poorly understood. Advances in recording and manipulating neuronal activity in specific cell types and axonal projections together with tools for circuit tracing are beginning to shed light on the neuronal circuit mechanisms of how internal, contextual signals shape sensory representations. Here we review r...
Source: Current Opinion in Neurobiology - June 5, 2018 Category: Neurology Authors: Khan AG, Hofer SB Tags: Curr Opin Neurobiol Source Type: research

To move or to sense? Incorporating somatosensory representation into striatal functions.
Abstract A long-standing hypothesis postulates that the striatum is essential for the concurrent selection of adaptive actions and repression of inappropriate alternatives. Here, classical and recent anatomical and physiological studies are reviewed to show that, in mammals, the striatum can detect discrete task-relevant sensory stimuli and continuously track somatosensory information associated with the generation of simple movements and more complex actions. Rather than contributing to the immediate selection of actions, the striatum may monitor the sensorimotor state of animals by integrating somatosensory info...
Source: Current Opinion in Neurobiology - May 31, 2018 Category: Neurology Authors: Robbe D Tags: Curr Opin Neurobiol Source Type: research

Bottom-up and top-down modulation of multisensory integration.
Abstract Sensory perception in the real world requires proper integration of different modality inputs. Process of multisensory integration is not uniform. It varies from individual to individual and changes at different behavioral states of the animal. What factors affect multisensory integration? How does the mammalian brain reconstruct a multisensory world at different states? Here, we summarize recent findings on bottom-up and top-down factors that can modulate sensory processing and multisensory integration. We discuss cortical circuits that are responsible for modulation of multisensory processing based on r...
Source: Current Opinion in Neurobiology - May 17, 2018 Category: Neurology Authors: Choi I, Lee JY, Lee SH Tags: Curr Opin Neurobiol Source Type: research

Plasticity of population coding in primary sensory cortex.
Abstract That experience shapes sensory tuning in primary sensory cortex is well understood. But effective neural population codes depend on more than just sensory tuning. Recent population imaging and recording studies have characterized population codes in sensory cortex, and tracked how they change with sensory manipulations and training on perceptual learning tasks. These studies confirm sensory tuning changes, but also reveal other features of plasticity, including sensory gain modulation, restructuring of firing correlations, and differential routing of information to output pathways. Unexpectedly strong day...
Source: Current Opinion in Neurobiology - May 15, 2018 Category: Neurology Authors: LeMessurier AM, Feldman DE Tags: Curr Opin Neurobiol Source Type: research

Progress and remaining challenges in high-throughput volume electron microscopy.
Abstract Recent advances in the effectiveness of the automatic extraction of neural circuits from volume electron microscopy data have made us more optimistic that the goal of reconstructing the nervous system of an entire adult mammal (or bird) brain can be achieved in the next decade. The progress on the data analysis side-based mostly on variants of convolutional neural networks-has been particularly impressive, but improvements in the quality and spatial extent of published VEM datasets are substantial. Methodologically, the combination of hot-knife sample partitioning and ion milling stands out as a conceptua...
Source: Current Opinion in Neurobiology - May 11, 2018 Category: Neurology Authors: Kornfeld J, Denk W Tags: Curr Opin Neurobiol Source Type: research

Editorial overview: Neurotechnologies.
PMID: 29754872 [PubMed - as supplied by publisher] (Source: Current Opinion in Neurobiology)
Source: Current Opinion in Neurobiology - May 10, 2018 Category: Neurology Authors: Anikeeva P, Luo L Tags: Curr Opin Neurobiol Source Type: research

Converging cellular themes for the hereditary spastic paraplegias.
Abstract Hereditary spastic paraplegias (HSPs) are neurologic disorders characterized by prominent lower-extremity spasticity, resulting from a length-dependent axonopathy of corticospinal upper motor neurons. They are among the most genetically-diverse neurologic disorders, with>80 distinct genetic loci and over 60 identified genes. Studies investigating the molecular pathogenesis underlying HSPs have emphasized the importance of converging cellular pathogenic themes in the most common forms of HSP, providing compelling targets for therapy. Most notably, these include organelle shaping and biogenesis as well a...
Source: Current Opinion in Neurobiology - May 10, 2018 Category: Neurology Authors: Blackstone C Tags: Curr Opin Neurobiol Source Type: research

Magnetic Resonance Imaging technology-bridging the gap between noninvasive human imaging and optical microscopy.
Abstract Technological advances in Magnetic Resonance Imaging (MRI) have provided substantial gains in the sensitivity and specificity of functional neuroimaging. Mounting evidence demonstrates that the hemodynamic changes utilized in functional MRI can be far more spatially and thus neuronally specific than previously believed. This has motivated a push toward novel, high-resolution MR imaging strategies that can match this biological resolution limit while recording from the entire human brain. Although sensitivity increases are a necessary component, new MR encoding technologies are required to convert improved...
Source: Current Opinion in Neurobiology - May 10, 2018 Category: Neurology Authors: Polimeni JR, Wald LL Tags: Curr Opin Neurobiol Source Type: research

Constraints on somatosensory map development: mutants lead the way.
Abstract In the rodent somatosensory system, the disproportionally large whisker representation and their specialization into barrel-shaped units in the different sensory relays has offered experimentalists with an ideal tool to identify mechanisms involved in brain map formation. These combine three intertwined constraints: Firstly, fasciculation of the incoming axons; secondly, early neural activity; finally, molecular patterning. Sophisticated genetic manipulations in mice have now allowed dissecting these mechanisms with greater accuracy. Here we discuss some recent papers that provided novel insights into how...
Source: Current Opinion in Neurobiology - May 9, 2018 Category: Neurology Authors: Gaspar P, Renier N Tags: Curr Opin Neurobiol Source Type: research

Tau-mediated synaptic and neuronal dysfunction in neurodegenerative disease.
Abstract The accumulation of pathological tau in the brain is associated with neuronal deterioration and cognitive impairments in tauopathies including Alzheimer's disease. Tau, while primarily localized in the axons of healthy neurons, accumulates in the soma and dendrites of neurons under pathogenic conditions. Tau is found in both presynaptic and postsynaptic compartments of neurons in Alzheimer's disease. New research supports that soluble forms of tau trigger pathophysiology in the brain by altering properties of synaptic and neuronal function at the early stages of disease progression, before neurons die. He...
Source: Current Opinion in Neurobiology - May 9, 2018 Category: Neurology Authors: Tracy TE, Gan L Tags: Curr Opin Neurobiol Source Type: research

Single cell transcriptomics in neuroscience: cell classification and beyond.
Abstract Biology has been facing a daunting problem since the cell was understood to be the building block of metazoans: how do we study multicellular systems, when a universal approach to characterize their building blocks and classify them does not exist? Metazoan diversity has not helped: there are many model and non-model organisms, developmental and adult stages, healthy and diseased states. Here, I review the application of single cell transcriptomics to cell classification in neuroscience and its corollaries: the differentially expressed genes discovered in this process are a treasure trove for understandin...
Source: Current Opinion in Neurobiology - May 5, 2018 Category: Neurology Authors: Tasic B Tags: Curr Opin Neurobiol Source Type: research

Development of the whisker-to-barrel cortex system.
HJ Abstract This review provides an overview on the development of the rodent whisker-to-barrel cortex system from late embryonic stage to the end of the first postnatal month. During this period the system shows a remarkable transition from a mostly genetic-molecular driven generation of crude connectivity, providing the template for activity-dependent structural and functional maturation and plasticity, to the manifestation of a complex behavioral repertoire including social interactions. Spontaneous and sensory-evoked activity is present in neonatal barrel cortex and control the generation of the cortical arch...
Source: Current Opinion in Neurobiology - May 5, 2018 Category: Neurology Authors: Yang JW, Kilb W, Kirischuk S, Unichenko P, Stüttgen MC, Luhmann HJ Tags: Curr Opin Neurobiol Source Type: research

Cortical developmental death: selected to survive or fated to die.
Abstract The mature cerebral cortex only contains a fraction of the cells that are generated during embryonic development. Indeed some neuronal populations are produced in excess and later subjected to partial elimination whereas others are almost completely removed during the first two postnatal weeks in mice. Although the identity of cells that disappear, the time course and mechanisms of their death are becoming reasonably well established, the meaning of producing supernumerary cells still remains elusive. In this review, we focus on recent data that shed a new light on the mechanisms involved in adjusting cel...
Source: Current Opinion in Neurobiology - May 5, 2018 Category: Neurology Authors: Causeret F, Coppola E, Pierani A Tags: Curr Opin Neurobiol Source Type: research

The neural circuits of thermal perception.
Abstract Thermal information about skin surface temperature is a key sense for the perception of object identity and valence. The identification of ion channels involved in the transduction of thermal changes has provided a genetic access point to the thermal system. However, from sensory specific 'labeled-lines' to multimodal interactive pathways, the functional organization and identity of the neural circuits mediating innocuous thermal perception have been debated for over 100 years. Here we highlight points in the system that require further attention and review recent advances using in vivo electrophysiology,...
Source: Current Opinion in Neurobiology - May 4, 2018 Category: Neurology Authors: Bokiniec P, Zampieri N, Lewin GR, Poulet JF Tags: Curr Opin Neurobiol Source Type: research

Origin and circuitry of spinal locomotor interneurons generating different speeds.
Abstract The spinal circuitry governing the undulatory movements of swimming vertebrates consist of excitatory and commissural inhibitory interneurons and motor neurons. This locomotor network generates the rhythmic output, coordinate left/right alternation, and permit communication across segments. Through evolution, more complex movement patterns have emerged, made possible by sub-specialization of neural populations within the spinal cord. Walking tetrapods use a similar basic circuitry, but have added layers of complexity for the coordination of intralimbic flexor and extensor muscles as well as interlimbic co...
Source: Current Opinion in Neurobiology - May 3, 2018 Category: Neurology Authors: Boije H, Kullander K Tags: Curr Opin Neurobiol Source Type: research

Experience-dependent plasticity in the lateral geniculate nucleus.
Abstract Experience-dependent plasticity in the visual system is traditionally thought to be exclusively cortical whereas the dorsal lateral geniculate nucleus (dLGN) is classically considered to just be a 'relay' of visual information between the retina and the cortex. However, a number of recent experiments call into question the simplistic view of visual cortex being the only site of plasticity. Thalamic neurons, at least in mouse dLGN, combine inputs from ganglion cells located in both eyes and recent evidence suggests that the feature selectivity of dLGN neurons is subject to experience-dependent plasticity. ...
Source: Current Opinion in Neurobiology - May 3, 2018 Category: Neurology Authors: Rose T, Bonhoeffer T Tags: Curr Opin Neurobiol Source Type: research

The hippocampus in depth: a sublayer-specific perspective of entorhinal-hippocampal function.
Abstract Understanding how the brain represents events is a fundamental question in neuroscience. The entorhinal-hippocampal system is central to such representations, which are severely compromised in some neurological diseases. In spite of much progress, a comprehensive, integrated view of spatial, temporal and other aspects of episodic representation remains elusive. Here, we review recent data on the role of cell-type specific entorhinal inputs which excite deep and superficial CA1 pyramidal cells by direct and indirect pathways. We discuss how an entorhinal dialogue with deep-superficial CA1 cells can multipl...
Source: Current Opinion in Neurobiology - May 2, 2018 Category: Neurology Authors: Valero M, de la Prida LM Tags: Curr Opin Neurobiol Source Type: research

What a predator can teach us about visual processing: a lesson from the archerfish.
Abstract The archerfish is a predator with highly unusual visually guided behavior. It is most famous for its ability to hunt by shooting water jets at static or dynamic insect prey, up to two meters above the water's surface. In the lab, the archerfish can learn to distinguish and shoot at artificial targets presented on a computer screen, thus enabling well-controlled experiments. In recent years, these capacities have turned the archerfish into a model animal for studying a variety of visual functions, from visual saliency and visual search, through fast visually guided prediction, and all the way to higher lev...
Source: Current Opinion in Neurobiology - May 1, 2018 Category: Neurology Authors: Ben-Tov M, Ben-Shahar O, Segev R Tags: Curr Opin Neurobiol Source Type: research

Action and learning shape the activity of neuronal circuits in the visual cortex.
Abstract Nonsensory variables strongly influence neuronal activity in the adult mouse primary visual cortex. Neuronal responses to visual stimuli are modulated by behavioural state, such as arousal and motor activity, and are shaped by experience. This dynamic process leads to neural representations in the visual cortex that reflect stimulus familiarity, expectations of reward and object location, and mismatch between self-motion and visual-flow. The recent development of genetic tools and recording techniques in awake behaving mice has enabled the investigation of the circuit mechanisms underlying state-dependent...
Source: Current Opinion in Neurobiology - May 1, 2018 Category: Neurology Authors: Pakan JM, Francioni V, Rochefort NL Tags: Curr Opin Neurobiol Source Type: research

Thalamocortical function in developing sensory circuits.
Abstract Thalamocortical activity patterns, both spontaneous and evoked, undergo a dramatic shift in preparation for the onset of rich sensory experience (e.g. birth in humans; eye-opening in rodents). This change is the result of a switch from thalamocortical circuits tuned for transmission of spontaneous bursting in sense organs, to circuits capable of high resolution, active sensory processing. Early 'pre-sensory' tuning uses amplification generated by corticothalamic excitatory feedback and early-born subplate neurons to ensure transmission of bursts, at the expense of stimulus discrimination. The switch to se...
Source: Current Opinion in Neurobiology - April 28, 2018 Category: Neurology Authors: Colonnese MT, Phillips MA Tags: Curr Opin Neurobiol Source Type: research

Neural encoding of sensory and behavioral complexity in the auditory cortex.
Abstract Converging evidence now supports the idea that auditory cortex is an important step for the emergence of auditory percepts. Recent studies have extended the list of complex, nonlinear sound features coded by cortical neurons. Moreover, we are beginning to uncover general properties of cortical representations, such as invariance and discreteness, which reflect the structure of auditory perception. Complexity, however, emerges not only through nonlinear shaping of auditory information into perceptual bricks. Behavioral context and task-related information strongly influence cortical encoding of sounds via ...
Source: Current Opinion in Neurobiology - April 27, 2018 Category: Neurology Authors: Kuchibhotla K, Bathellier B Tags: Curr Opin Neurobiol Source Type: research

Memory circuits: CA2.
Abstract The hippocampus is a central region in the coding of spatial, temporal and episodic memory. Recent discoveries have revealed surprising and complex roles of the small area CA2 in hippocampal function. Lesion studies have revealed that this region is required for social memory formation. Area CA2 is targeted by extra-hippocampal paraventricular inputs that release vasopressin and can act to enhance social memory performance. In vivo recordings have revealed nonconventional activity by neurons in this region that act to both initiate hippocampal sharp-wave ripple events as well as encode spatial information...
Source: Current Opinion in Neurobiology - April 26, 2018 Category: Neurology Authors: Piskorowski RA, Chevaleyre V Tags: Curr Opin Neurobiol Source Type: research

Neuronal coding mechanisms mediating fear behavior.
Abstract The behavioral repertoire of an organism can be highly diverse, spanning from social to defensive. How an animal efficiently switches between distinct behaviors is a fundamental question whose inquiry will provide insights into the mechanisms that are necessary for an organism's survival. Previous work aimed at identifying the neural systems responsible for defensive behaviors, such as freezing, has demonstrated critical interactions between the prefrontal cortex and amygdala. Indeed, this foundational research has provided an indispensable anatomical framework that investigators are now using to understa...
Source: Current Opinion in Neurobiology - April 26, 2018 Category: Neurology Authors: Rozeske RR, Herry C Tags: Curr Opin Neurobiol Source Type: research

Molecular diversity underlying cortical excitatory and inhibitory synapse development.
Abstract The complexity and precision of cortical circuitries is achieved during development due to the exquisite diversity of synapse types that is generated in a highly regulated manner. Here, we review the recent increase in our understanding of how synapse type-specific molecules differentially regulate the development of excitatory and inhibitory synapses. Moreover, several synapse subtype-specific molecules have been shown to control the targeting, formation or maturation of particular subtypes of excitatory synapses. Because inhibitory neurons are extremely diverse, a similar molecular diversity is likely t...
Source: Current Opinion in Neurobiology - April 25, 2018 Category: Neurology Authors: Favuzzi E, Rico B Tags: Curr Opin Neurobiol Source Type: research

Developmental interactions between thalamus and cortex: a true love reciprocal story.
ute;pez-Bendito G Abstract The developmental programs that control the specification of cortical and thalamic territories are maintained largely as independent processes. However, bulk of evidence demonstrates the requirement of the reciprocal interactions between cortical and thalamic neurons as key for the correct development of functional thalamocortical circuits. This reciprocal loop of connections is essential for sensory processing as well as for the execution of complex sensory-motor tasks. Here, we review recent advances in our understanding of how mutual collaborations between both brain regions define ar...
Source: Current Opinion in Neurobiology - April 25, 2018 Category: Neurology Authors: Antón-Bolaños N, Espinosa A, López-Bendito G Tags: Curr Opin Neurobiol Source Type: research

Personalized brain network models for assessing structure-function relationships.
We describe the steps necessary to build such models and show how this computational approach can provide previously unobtainable information through the ability to perform virtual experiments. Finally, we present examples of how personalized brain network models can be used to gain insight into the effects of local stimulation and improve surgical outcomes in epilepsy. PMID: 29704749 [PubMed - as supplied by publisher] (Source: Current Opinion in Neurobiology)
Source: Current Opinion in Neurobiology - April 25, 2018 Category: Neurology Authors: Bansal K, Nakuci J, Muldoon SF Tags: Curr Opin Neurobiol Source Type: research

Active mechanosensory feedback during locomotion in the zebrafish spinal cord.
Abstract The investigation of mechanosensory feedback to locomotion has been hindered by the challenge of recording neurons in motion. Genetic accessibility and optical transparency of zebrafish larvae provide means to revisit this question. Glutamatergic Rohon-Beard (RB) and GABAergic CSF-contacting neurons (CSF-cNs) are spinal mechanosensory neurons. Recent studies combining bioluminescence, silencing and optogenetic activation show that mechanosensory neurons enhance speed and stabilize posture during locomotion. RB neurons can modulate speed by projecting onto glutamatergic premotor V2a interneurons during fas...
Source: Current Opinion in Neurobiology - April 25, 2018 Category: Neurology Authors: Knafo S, Wyart C Tags: Curr Opin Neurobiol Source Type: research

Neural and genetic basis of dexterous hand movements.
Abstract An ability to control dexterous hand movements is considered to parallel the evolutionary development of the corticospinal tract and the appearance of direct connections between corticospinal neurons and motoneurons (the corticomotoneuronal (CM) pathway), which developed uniquely in higher primates. However, recent studies have revealed that some non-primate animal species have higher levels of dexterity than previously supposed, and in higher primates, various indirect non-CM descending pathways have been shown to participate in the control of dexterous movements. More recently, the CM pathway was shown ...
Source: Current Opinion in Neurobiology - April 23, 2018 Category: Neurology Authors: Yoshida Y, Isa T Tags: Curr Opin Neurobiol Source Type: research

Socio-sexual processing in cortical circuits.
Abstract How does social and sexual information processing map onto cortical circuits? Addressing this question has been difficult, because of a lack of circuit-oriented social neuroscience and an absence of measurements from interacting brains. Recent work showed social information is already differentially processed in the primary sensory cortices. Converging evidence suggests that prefrontal areas contribute to social interaction processing and determining social hierarchies. In social interactions, we identify gender in split seconds, but after centuries of anatomy we are still unable to distinguish male and f...
Source: Current Opinion in Neurobiology - April 22, 2018 Category: Neurology Authors: Brecht M, Lenschow C, Rao RP Tags: Curr Opin Neurobiol Source Type: research

Behavioral readout of spatio-temporal codes in olfaction.
Abstract Neural recordings performed at an increasing scale and resolution have revealed complex, spatio-temporally precise patterns of activity in the olfactory system. Multiple models may explain the functional consequences of the spatio-temporal olfactory code, but the link to behavior remains unclear. Recent evidence in the field suggests a behavioral sensitivity to both fine spatial and temporal features in the code. How these features and combinations of features give rise to olfactory behavior is the subject of active research in the field. Modern genetic and optogenetic methods show great promise in testin...
Source: Current Opinion in Neurobiology - April 22, 2018 Category: Neurology Authors: Chong E, Rinberg D Tags: Curr Opin Neurobiol Source Type: research

Vestibular signals in primate cortex for self-motion perception.
Abstract The vestibular peripheral organs in our inner ears detect transient motion of the head in everyday life. This information is sent to the central nervous system for automatic processes such as vestibulo-ocular reflexes, balance and postural control, and higher cognitive functions including perception of self-motion and spatial orientation. Recent neurophysiological studies have discovered a prominent vestibular network in the primate cerebral cortex. Many of the areas involved are multisensory: their neurons are modulated by both vestibular signals and visual optic flow, potentially facilitating more robus...
Source: Current Opinion in Neurobiology - April 21, 2018 Category: Neurology Authors: Gu Y Tags: Curr Opin Neurobiol Source Type: research

Transcription factor mechanisms guiding motor neuron differentiation and diversification.
Abstract The embryonic generation of motor neurons is a complex process involving progenitor patterning, fate specification, differentiation, and maturation. Throughout this progression, the differential expression of transcription factors has served as our road map for the eventual cell fate of nascent motor neurons. Recent findings from in vivo and in vitro models of motor neuron development have expanded our understanding of how transcription factors govern motor neuron identity and their individual regulatory mechanisms. With the advent of next generation sequencing approaches, researchers now have unprecedent...
Source: Current Opinion in Neurobiology - April 21, 2018 Category: Neurology Authors: Cave C, Sockanathan S Tags: Curr Opin Neurobiol Source Type: research

Ultrasonic modulation of neural circuit activity.
Abstract Ultrasound (US) is recognized for its use in medical imaging as a diagnostic tool. As an acoustic energy source, US has become increasingly appreciated over the past decade for its ability to non-invasively modulate cellular activity including neuronal activity. Data obtained from a host of experimental models has shown that low-intensity US can reversibly modulate the physiological activity of neurons in peripheral nerves, spinal cord, and intact brain circuits. Experimental evidence indicates that acoustic pressures exerted by US act, in part, on mechanosensitive ion channels to modulate activity. While...
Source: Current Opinion in Neurobiology - April 16, 2018 Category: Neurology Authors: Tyler WJ, Lani SW, Hwang GM Tags: Curr Opin Neurobiol Source Type: research

Holographic imaging and photostimulation of neural activity.
Abstract Optical imaging methods are powerful tools in neuroscience as they can systematically monitor the activity of neuronal populations with high spatiotemporal resolution using calcium or voltage indicators. Moreover, caged compounds and optogenetic actuators enable to optically manipulate neural activity. Among optical methods, computer-generated holography offers an enormous flexibility to sculpt the excitation light in three-dimensions (3D), particularly when combined with two-photon light sources. By projecting holographic light patterns on the sample, the activity of multiple neurons across a 3D brain vo...
Source: Current Opinion in Neurobiology - April 13, 2018 Category: Neurology Authors: Yang W, Yuste R Tags: Curr Opin Neurobiol Source Type: research

Probing the brain with molecular fMRI.
Abstract One of the greatest challenges of modern neuroscience is to incorporate our growing knowledge of molecular and cellular-scale physiology into integrated, organismic-scale models of brain function in behavior and cognition. Molecular-level functional magnetic resonance imaging (molecular fMRI) is a new technology that can help bridge these scales by mapping defined microscopic phenomena over large, optically inaccessible regions of the living brain. In this review, we explain how MRI-detectable imaging probes can be used to sensitize noninvasive imaging to mechanistically significant components of neural p...
Source: Current Opinion in Neurobiology - April 9, 2018 Category: Neurology Authors: Ghosh S, Harvey P, Simon JC, Jasanoff A Tags: Curr Opin Neurobiol Source Type: research

High-speed 3D imaging of cellular activity in the brain using axially-extended beams and light sheets.
This article describes these approaches and presents a simple model that demonstrates key advantages of axially-extended illumination over point-scanning strategies for high-speed volumetric imaging, including longer integration times per voxel, improved photon efficiency and reduced photodamage. PMID: 29642044 [PubMed - as supplied by publisher] (Source: Current Opinion in Neurobiology)
Source: Current Opinion in Neurobiology - April 7, 2018 Category: Neurology Authors: Hillman EM, Voleti V, Patel K, Li W, Yu H, Perez-Campos C, Benezra SE, Bruno RM, Galwaduge PT Tags: Curr Opin Neurobiol Source Type: research

Towards circuit optogenetics.
Abstract Optogenetics neuronal targeting combined with single-photon wide-field illumination has already proved its enormous potential in neuroscience, enabling the optical control of entire neuronal networks and disentangling their role in the control of specific behaviors. However, establishing how a single or a sub-set of neurons controls a specific behavior, or how functionally identical neurons are connected in a particular task, or yet how behaviors can be modified in real-time by the complex wiring diagram of neuronal connections requires more sophisticated approaches enabling to drive neuronal circuits act...
Source: Current Opinion in Neurobiology - April 6, 2018 Category: Neurology Authors: Chen IW, Papagiakoumou E, Emiliani V Tags: Curr Opin Neurobiol Source Type: research