- Home
- A-Z Publications
- Annual Review of Neuroscience
- Previous Issues
- Volume 36, 2013
Annual Review of Neuroscience - Volume 36, 2013
Volume 36, 2013
-
-
Active Properties of Neocortical Pyramidal Neuron Dendrites
Vol. 36 (2013), pp. 1–24More LessDendrites are the main recipients of synaptic inputs and are important sites that determine neurons' input-output functions. This review focuses on thin neocortical dendrites, which receive the vast majority of synaptic inputs in cortex but also have specialized electrogenic properties. We present a simplified working-model biophysical scheme of pyramidal neurons that attempts to capture the essence of their dendritic function, including the ability to behave under plausible conditions as dynamic computational subunits. We emphasize the electrogenic capabilities of NMDA receptors (NMDARs) because these transmitter-gated channels seem to provide the major nonlinear depolarizing drive in thin dendrites, even allowing full-blown NMDA spikes. We show how apparent discrepancies in experimental findings can be reconciled and discuss the current status of dendritic spikes in vivo; a dominant NMDAR contribution would indicate that the input-output relations of thin dendrites are dynamically set by network activity and cannot be fully predicted by purely reductionist approaches.
-
-
-
Episodic Neurologic Disorders: Syndromes, Genes, and Mechanisms
Vol. 36 (2013), pp. 25–50More LessMany neurologic diseases cause discrete episodic impairment in contrast with progressive deterioration. The symptoms of these episodic disorders exhibit striking variety. Herein we review what is known of the phenotypes, genetics, and pathophysiology of episodic neurologic disorders. Of these, most are genetically complex, with unknown or polygenic inheritance. In contrast, a fascinating panoply of episodic disorders exhibit Mendelian inheritance. We classify episodic Mendelian disorders according to the primary neuroanatomical location affected: skeletal muscle, cardiac muscle, neuromuscular junction, peripheral nerve, or central nervous system (CNS). Most known Mendelian mutations alter genes that encode membrane-bound ion channels. These mutations cause ion channel dysfunction, which ultimately leads to altered membrane excitability as manifested by episodic disease. Other Mendelian disease genes encode proteins essential for ion channel trafficking or stability. These observations have cemented the channelopathy paradigm, in which episodic disorders are conceptualized as disorders of ion channels. However, we expand on this paradigm to propose that dysfunction at the synaptic and neuronal circuit levels may underlie some episodic neurologic entities.
-
-
-
Developmental Mechanisms of Topographic Map Formation and Alignment
Vol. 36 (2013), pp. 51–77More LessBrain connections are organized into topographic maps that are precisely aligned both within and across modalities. This alignment facilitates coherent integration of different categories of sensory inputs and allows for proper sensorimotor transformations. Topographic maps are established and aligned by multistep processes during development, including interactions of molecular guidance cues expressed in gradients; spontaneous activity-dependent axonal and dendritic remodeling; and sensory-evoked plasticity driven by experience. By focusing on the superior colliculus, a major site of topographic map alignment for different sensory modalities, this review summarizes current understanding of topographic map development in the mammalian visual system and highlights recent advances in map alignment studies. A major goal looking forward is to reveal the molecular and synaptic mechanisms underlying map alignment and to understand the physiological and behavioral consequences when these mechanisms are disrupted at various scales.
-
-
-
Sleep for Preserving and Transforming Episodic Memory
Marion Inostroza, and Jan BornVol. 36 (2013), pp. 79–102More LessSleep is known to support memory consolidation. Here we review evidence for an active system consolidation occurring during sleep. At the beginning of this process is sleep's ability to preserve episodic experiences preferentially encoded in hippocampal networks. Repeated neuronal reactivation of these representations during slow-wave sleep transforms episodic representations into long-term memories, redistributes them toward extrahippocampal networks, and qualitatively changes them to decontextualized schema-like representations. Electroencephalographic (EEG) oscillations regulate the underlying communication: Hippocampal sharp-wave ripples coalescing with thalamic spindles mediate the bottom-up transfer of reactivated memory information to extrahippocampal regions. Neocortical slow oscillations exert a supraordinate top-down control to synchronize hippocampal reactivations of specific memories to their excitable up-phase, thus allowing plastic changes in extrahippocampal regions. We propose that reactivations during sleep are a general mechanism underlying the abstraction of temporally stable invariants from a flow of input that is solely structured in time, thus representing a basic mechanism of memory formation.
-
-
-
Computational Identification of Receptive Fields
Vol. 36 (2013), pp. 103–120More LessNatural stimuli elicit robust responses of neurons throughout sensory pathways, and therefore their use provides unique opportunities for understanding sensory coding. This review describes statistical methods that can be used to characterize neural feature selectivity, focusing on the case of natural stimuli. First, we discuss how such classic methods as reverse correlation/spike-triggered average and spike-triggered covariance can be generalized for use with natural stimuli to find the multiple relevant stimulus features that affect the responses of a given neuron. Second, ways to characterize neural feature selectivity while assuming that the neural responses exhibit a certain type of invariance, such as position invariance for visual neurons, are discussed. Finally, we discuss methods that do not require one to make an assumption of invariance and instead can determine the type of invariance by analyzing relationships between the multiple stimulus features that affect the neural responses.
-
-
-
The Evolution of Drosophila melanogaster as a Model for Alcohol Research
Vol. 36 (2013), pp. 121–138More LessAnimal models have been widely used to gain insight into the mechanisms underlying the acute and long-term effects of alcohol exposure. The fruit fly Drosophila melanogaster encounters ethanol in its natural habitat and possesses many adaptations that allow it to survive and thrive in ethanol-rich environments. Several assays to study ethanol-related behaviors in flies, ranging from acute intoxication to self-administration and reward, have been developed in the past 20 years. These assays have provided the basis for studying the physiological and behavioral effects of ethanol and for identifying genes mediating these effects. In this review we describe the ecological relationship between flies and ethanol, the effects of ethanol on fly development and behavior, the use of flies as a model for alcohol addiction, and the interaction between ethanol and social behavior. We discuss these advances in the context of their utility to help decipher the mechanisms underlying the diverse effects of ethanol, including those that mediate ethanol dependence and addiction in humans.
-
-
-
From Atomic Structures to Neuronal Functions of G Protein–Coupled Receptors
Vol. 36 (2013), pp. 139–164More LessG protein–coupled receptors (GPCRs) are essential mediators of signal transduction, neurotransmission, ion channel regulation, and other cellular events. GPCRs are activated by diverse stimuli, including light, enzymatic processing of their N-termini, and binding of proteins, peptides, or small molecules such as neurotransmitters. GPCR dysfunction caused by receptor mutations and environmental challenges contributes to many neurological diseases. Moreover, modern genetic technology has helped identify a rich array of mono- and multigenic defects in humans and animal models that connect such receptor dysfunction with disease affecting neuronal function. The visual system is especially suited to investigate GPCR structure and function because advanced imaging techniques permit structural studies of photoreceptor neurons at both macro and molecular levels that, together with biochemical and physiological assessment in animal models, provide a more complete understanding of GPCR signaling.
-
-
-
Superior Colliculus and Visual Spatial Attention
Vol. 36 (2013), pp. 165–182More LessThe superior colliculus (SC) has long been known to be part of the network of brain areas involved in spatial attention, but recent findings have dramatically refined our understanding of its functional role. The SC both implements the motor consequences of attention and plays a crucial role in the process of target selection that precedes movement. Moreover, even in the absence of overt orienting movements, SC activity is related to shifts of covert attention and is necessary for the normal control of spatial attention during perceptual judgments. The neuronal circuits that link the SC to spatial attention may include attention-related areas of the cerebral cortex, but recent results show that the SC's contribution involves mechanisms that operate independently of the established signatures of attention in visual cortex. These findings raise new issues and suggest novel possibilities for understanding the brain mechanisms that enable spatial attention.
-
-
-
Genetic Approaches to Neural Circuits in the Mouse
Vol. 36 (2013), pp. 183–215More LessTo understand the organization and assembly of mammalian brain circuits, we need a comprehensive tool set that can address the challenges of cellular diversity, spatial complexity at synapse resolution, dynamic complexity of circuit operations, and multifaceted developmental processes rooted in the genome. Complementary to physics- and chemistry-based methods, genetic tools tap into intrinsic cellular and developmental mechanisms. Thus, they have the potential to achieve appropriate spatiotemporal resolution and the cellular-molecular specificity necessary for observing and probing the makings and inner workings of neurons and neuronal circuits. Furthermore, genetic analysis will be key to unraveling the intricate link from genes to circuits to systems, in part through systematic targeting and tracking of individual cellular components of neural circuits. Here we review recent progress in genetic tool development and advances in genetic analysis of neural circuits in the mouse. We also discuss future directions and implications for understanding brain disorders.
-
-
-
Early Olfactory Processing in Drosophila: Mechanisms and Principles
Vol. 36 (2013), pp. 217–241More LessIn the olfactory system of Drosophila melanogaster, it is relatively straightforward to target in vivo measurements of neural activity to specific processing channels. This, together with the numerical simplicity of the Drosophila olfactory system, has produced rapid gains in our understanding of Drosophila olfaction. This review summarizes the neurophysiology of the first two layers of this system: the peripheral olfactory receptor neurons and their postsynaptic targets in the antennal lobe. We now understand in some detail the cellular and synaptic mechanisms that shape odor representations in these neurons. Together, these mechanisms imply that interesting neural adaptations to environmental statistics have occurred. These mechanisms also place some fundamental constraints on early sensory processing that pose challenges for higher brain regions. These findings suggest some general principles with broad relevance to early sensory processing in other modalities.
-
-
-
RNA Protein Interaction in Neurons
Vol. 36 (2013), pp. 243–270More LessNeurons have their own systems for regulating RNA. Several multigene families encode RNA binding proteins (RNABPs) that are uniquely expressed in neurons, including the well-known neuron-specific markers ELAV and NeuN and the disease antigen NOVA. New technologies have emerged in recent years to assess the function of these proteins in vivo, and the answers are yielding insights into how and why neurons may regulate RNA in special ways—to increase cellular complexity, to localize messenger RNA (mRNA) spatially, and to regulate their expression in response to synaptic stimuli. The functions of such restricted neuronal proteins are likely to be complemented by more widely expressed RNABPs that may themselves have developed specialized functions in neurons, including Argonaute/microRNAs (miRNAs). Here we review what is known about such RNABPs and explore the potential biologic and neurologic significance of neuronal RNA regulatory systems.
-
-
-
Muscarinic Signaling in the Brain
Vol. 36 (2013), pp. 271–294More LessMuscarinic signaling affects attention, action selection, learning, and memory through multiple signaling cascades, which act at different timescales and which alter ion channels in cell type–specific manners. The effects of muscarinic signaling differ between cortical layers and between brain areas. Muscarinic signaling adds flexibility to the processing mode of neuronal networks, thereby supporting processing according to task demands. This review outlines possible scenarios to describe how it contributes to cellular mechanisms of attention and how it affects channeling of information in different neuronal circuits.
-
-
-
Mechanisms and Functions of Theta Rhythms
Vol. 36 (2013), pp. 295–312More LessThe theta rhythm is one of the largest and most sinusoidal activity patterns in the brain. Here I survey progress in the field of theta rhythms research. I present arguments supporting the hypothesis that theta rhythms emerge owing to intrinsic cellular properties yet can be entrained by several theta oscillators throughout the brain. I review behavioral correlates of theta rhythms and consider how these correlates inform our understanding of theta rhythms' functions. I discuss recent work suggesting that one function of theta is to package related information within individual theta cycles for more efficient spatial memory processing. Studies examining the role of theta phase precession in spatial memory, particularly sequence retrieval, are also summarized. Additionally, I discuss how interregional coupling of theta rhythms facilitates communication across brain regions. Finally, I conclude by summarizing how theta rhythms may support cognitive operations in the brain, including learning.
-
-
-
Neural Basis of the Perception and Estimation of Time
Vol. 36 (2013), pp. 313–336More LessUnderstanding how sensory and motor processes are temporally integrated to control behavior in the hundredths of milliseconds-to-minutes range is a fascinating problem given that the basic electrophysiological properties of neurons operate on a millisecond timescale. Single-unit recording studies in monkeys have identified localized timing circuits, whereas neuropsychological studies of humans who have damage to the basal ganglia have indicated that core structures, such as the cortico-thalamic-basal ganglia circuit, play an important role in timing and time perception. Taken together, these data suggest that a core timing mechanism interacts with context-dependent areas. This idea of a temporal hub with a distributed network is used to investigate the abstract properties of interval tuning as well as temporal illusions and intersensory timing. We conclude by proposing that the interconnections built into this core timing mechanism are designed to provide a form of degeneracy as protection against injury, disease, or age-related decline.
-
-
-
Cortical Control of Arm Movements: A Dynamical Systems Perspective
Vol. 36 (2013), pp. 337–359More LessOur ability to move is central to everyday life. Investigating the neural control of movement in general, and the cortical control of volitional arm movements in particular, has been a major research focus in recent decades. Studies have involved primarily either attempts to account for single-neuron responses in terms of tuning for movement parameters or attempts to decode movement parameters from populations of tuned neurons. Even though this focus on encoding and decoding has led to many seminal advances, it has not produced an agreed-upon conceptual framework. Interest in understanding the underlying neural dynamics has recently increased, leading to questions such as how does the current population response determine the future population response, and to what purpose? We review how a dynamical systems perspective may help us understand why neural activity evolves the way it does, how neural activity relates to movement parameters, and how a unified conceptual framework may result.
-
-
-
The Genetics of Hair Cell Development and Regeneration
Vol. 36 (2013), pp. 361–381More LessSensory hair cells are exquisitely sensitive vertebrate mechanoreceptors that mediate the senses of hearing and balance. Understanding the factors that regulate the development of these cells is important, not only to increase our understanding of ear development and its functional physiology but also to shed light on how these cells may be replaced therapeutically. In this review, we describe the signals and molecular mechanisms that initiate hair cell development in vertebrates, with particular emphasis on the transcription factor Atoh1, which is both necessary and sufficient for hair cell development. We then discuss recent findings on how microRNAs may modulate the formation and maturation of hair cells. Last, we review recent work on how hair cells are regenerated in many vertebrate groups and the factors that conspire to prevent this regeneration in mammals.
-
-
-
Neuronal Computations in the Olfactory System of Zebrafish
Vol. 36 (2013), pp. 383–402More LessThe main olfactory system encodes information about molecules in a combinatorial fashion by distributed spatiotemporal activity patterns. As activity propagates from sensory neurons to the olfactory bulb and to higher brain areas, odor information is processed by multiple transformations of these activity patterns. This review discusses neuronal computations associated with such transformations in the olfactory system of zebrafish, a small vertebrate that offers advantages for the quantitative analysis and manipulation of neuronal activity in the intact brain. The review focuses on pattern decorrelation in the olfactory bulb and on the readout of multiplexed sensory representations in the telencephalic area Dp, the homolog of the olfactory cortex. These computations are difficult to study in larger species and may provide insights into general information-processing strategies in the brain.
-
-
-
Transformation of Visual Signals by Inhibitory Interneurons in Retinal Circuits
Vol. 36 (2013), pp. 403–428More LessOne of the largest mysteries of the brain lies in understanding how higher-level computations are implemented by lower-level operations in neurons and synapses. In particular, in many brain regions inhibitory interneurons represent a diverse class of cells, the individual functional roles of which are unknown. We discuss here how the operations of inhibitory interneurons influence the behavior of a circuit, focusing on recent results in the vertebrate retina. A key role in this understanding is played by a common representation of the visual stimulus that can be applied at different stages. By considering how this stimulus representation changes at each location in the circuit, we can understand how neuron-level operations such as thresholds and inhibition yield circuit-level computations such as how stimulus selectivity and gain are controlled by local and peripheral visual stimuli.
-
-
-
Electrical Compartmentalization in Dendritic Spines
Vol. 36 (2013), pp. 429–449More LessMost excitatory inputs in the CNS contact dendritic spines, avoiding dendritic shafts, so spines must play a key role for neurons. Recent data suggest that, in addition to enhancing connectivity and isolating synaptic biochemistry, spines can behave as electrical compartments independent from their parent dendrites. It is becoming clear that, although spines experience voltages similar to those of dendrites during action potentials (APs), spines must sustain higher depolarizations than do dendritic shafts during excitatory postsynaptic potentials (EPSPs). Synaptic potentials are likely amplified at the spine head and then reduced as they invade the dendrite through the spine neck. These electrical changes, probably due to a combination of passive and active mechanisms, may prevent the saturation of dendrites by the joint activation of many inputs, influence dendritic integration, and contribute to rapid synaptic plasticity. The electrical properties of spines could enable neural circuits to harness a high connectivity, implementing a “synaptic democracy,” where each input can be individually integrated, tallied, and modified in order to generate emergent functional states.
-
-
-
Prefrontal Contributions to Visual Selective Attention
Vol. 36 (2013), pp. 451–466More LessThe faculty of attention endows us with the capacity to process important sensory information selectively while disregarding information that is potentially distracting. Much of our understanding of the neural circuitry underlying this fundamental cognitive function comes from neurophysiological studies within the visual modality. Past evidence suggests that a principal function of the prefrontal cortex (PFC) is selective attention and that this function involves the modulation of sensory signals within posterior cortices. In this review, we discuss recent progress in identifying the specific prefrontal circuits controlling visual attention and its neural correlates within the primate visual system. In addition, we examine the persisting challenge of precisely defining how behavior should be affected when attentional function is lost.
-
Previous Volumes
-
Volume 47 (2024)
-
Volume 46 (2023)
-
Volume 45 (2022)
-
Volume 44 (2021)
-
Volume 43 (2020)
-
Volume 42 (2019)
-
Volume 41 (2018)
-
Volume 40 (2017)
-
Volume 39 (2016)
-
Volume 38 (2015)
-
Volume 37 (2014)
-
Volume 36 (2013)
-
Volume 35 (2012)
-
Volume 34 (2011)
-
Volume 33 (2010)
-
Volume 32 (2009)
-
Volume 31 (2008)
-
Volume 30 (2007)
-
Volume 29 (2006)
-
Volume 28 (2005)
-
Volume 27 (2004)
-
Volume 26 (2003)
-
Volume 25 (2002)
-
Volume 24 (2001)
-
Volume 23 (2000)
-
Volume 22 (1999)
-
Volume 21 (1998)
-
Volume 20 (1997)
-
Volume 19 (1996)
-
Volume 18 (1995)
-
Volume 17 (1994)
-
Volume 16 (1993)
-
Volume 15 (1992)
-
Volume 14 (1991)
-
Volume 13 (1990)
-
Volume 12 (1989)
-
Volume 11 (1988)
-
Volume 10 (1987)
-
Volume 9 (1986)
-
Volume 8 (1985)
-
Volume 7 (1984)
-
Volume 6 (1983)
-
Volume 5 (1982)
-
Volume 4 (1981)
-
Volume 3 (1980)
-
Volume 2 (1979)
-
Volume 1 (1978)
-
Volume 0 (1932)