bluuebunny/crossref_metadata_2025 huggingface dataset:
Stem Cells and Neuronal Progenitors and Their Diversity in the CNS: Are Time and Place Important?
Authors: Vaccarino Flora M.
Published: April 2009

Stem cells are multilineage progenitor cells that are capable of self-regenerating and giving rise to different cell types. The proper assembly of the CNS into functionally relevant circuits requires that stem cells produce the right types of cells in the right number and position at the appropriate time. We suggest that the positional specification of stem cells is provided by the pattern of expression of early transcriptional regulators along the body axes. These mechanisms restrict the competence of stem cells to programming a local cellular repertoire. Conversely, we argue that the specification of different cell types in the appropriate number and sequence is independently carried out within CNS domains by subprograms that progressively change the intrinsic properties of the stem cells. Temporal changes in proliferation and differentiation of stem cells are controlled by cascades of extracellular signals and basic helix-loop-helix (bHlH) transcription factors. These regulators in turn may activate homeodomain transcription factors with more restricted effector functions. Fibroblast growth factors (FGF) are among the earliest acting signals providing local changes in growth within the developing CNS. Basic FGF (FGF2) increases the proliferation of either stem cells or their immediate progeny, increasing the number of founder cells in the developing cerebral cortex.
Looking at Receptors: What Have Fluorescent Receptors and Channels Told Us?
Authors: Hughes Thomas E.
Published: April 2009

The receptors and channels that reside on the surface of a neuron enable it to respond to and integrate a wide variety of signals. Electrophysiology has made it possible to study the behavior of these channels in remarkable detail. For instance, patch-clamp recording has made it possible in many instances to actually resolve the opening and closing of individual channels. Similarly, immuncytochemistry has provided us with static images of where these proteins are in a neuron. Nevertheless, we know remarkably little about how these proteins are actually used by living cells. Fundamental questions concerning how long they are at the surface, how localized they are, how quickly they are internalized in response to activation, or how free they are to move about on the surface remain to be addressed. One way to answer such questions is to fluorescently label these proteins and image them in living cells. The discovery of the jellyfish green fluorescent protein has recently made this feasible, and the new views it is providing are the topic of this review.
Molecular Abnormalities in Brains of Depressed Patients
Authors: Dowlatshahi Dar , Young L. Trevor
Published: April 2009

Studies on the molecular pharmacology of antidepressants have lead to a reinterpretation of earlier models of the neuropathology of depression. Noradrenergic and serotonergic hypotheses of depression have been expanded to include postsynaptic intracellular signal transduction pathways and regulation of gene expression. Because much of this evidence was obtained from postmortem brain, there has been increased interest in the use of this tissue to study depression. In the following pages, we will review the postmortem brain studies in depressed individuals focusing on neurotransmitter systems, signal transduction, and structural abnormalities.
Cushing’s Contributions to Neuroscience, Part 1: Through the Looking Glass
Authors: Savitz Sean I.
Published: April 2009

Harvey Cushing (1869-1939) played a pivotal role in the birth of modern neurosurgery. At the turn of the century, when he was completing his surgical residency, medicine was just beginning to embrace scientific investigation as the main tool to diagnose and treat disease. Touring Europe after residency landed him in the laboratory of the great scientist Theodor Kocher, with whom he developed a modern understanding of the effects of increased intracranial pressure. This achievement helped Cushing transform neurosurgery into a viable specialty. An analysis of this early work in neuroscience reveals the ambition, ingenuity, and self-assurance of a budding scientist struggling to achieve recognition. This is the first of two reports on Cushing’s contributions to neuroscience.
Molecular Mimicry in Neurological Diseases
Authors: Markovic-Plese Silva
Published: April 2009

Several mechanisms have been implicated in the activation and expansion of myelin-specific T cells in multiple sclerosis, a presumed autoimmune disease of the central nervous system. In this article, we will review the mechanisms of molecular mimicry whereby myelin-specific T lymphocytes may be activated by foreign antigens. Recent studies from our laboratory have documented an unexpected flexibility of T cell receptor recognition and demonstrated that sequence homology is not a requirement for cross-recognition. Using synthetic combinatorial peptide libraries, it was possible to identify the entire spectrum of molecular mimics for T cell clones. This approach may prove useful for the development of antigen-specific therapies and vaccines.
Stem Cells and Regeneration in the Retina: What Fish Have Taught Us about Neurogenesis
Authors: Easter Stephen S. , Hitchcock Peter F.
Published: April 2009

Many species of fish grow for much of their lifetimes and add neurons to the CNS continuously. The retina has proved to be a convenient model in which to study neurogenesis, both the normal variety associated with growth and regeneration in response to a lesion. Initial neurogenesis in the embryonic eye cup begins in a tiny cluster of neuroepithelial cells that steadily enlarges to produce a central disk of neurons. Subsequent growth occurs mainly at the edge of this disk, in the circumferential germinal zone, where the retina adds annuli of new neurons of all varieties except the rod photoreceptors. A few proliferative cells persist to adulthood in central retina and normally produce only rods, but when the retina is damaged, these cells contribute to the production of new neurons of diverse classes. Recent work has revealed two additional populations of dividing cells in central retina; they normally proliferate so slowly that special methods are required to reveal them. We suggest that the three proliferative cell types are related through lineage in a model similar to those described for hematopoiesis. The persistent neurogenesis of fish retina seems to resemble qualitatively the neurogenesis of the mammalian brain, but quantitatively the neurogenesis is much more vigorous in the fish.
The Challenges and Rewards of Integrating Diverse Neuroscience Information
Authors: Gorin Fredric , Hogarth Michael , Gertz Michael
Published: April 2009

The design of database models and schemas for storing, cross-referencing, and retrieving neuroscience information faces issues that are similar but more complex than most of the other biomedical disciplines, such as genomics and proteonomics. Specifically, the visualization and manipulation of very large and diverse image data, such as digital brain atlases and functional magnetic resonance images, play a unique role in neuroscience while much of the associated information is textually recorded. Nongraphical information can include the annotation of large brain structures ranging from anatomical regions to intracellular structures, the description of cellular functional properties, and their various interrelationships, such as fiber connections. It is necessary that the heterogeneous and distributed types of data be cross-referenced to each other so that this diverse information can be efficiently retrieved, shared, and exchanged among the different neuroscientific disciplines. Continued advances in computers and Internet technologies appear to indicate that increasingly large data sets will be maintained on local or regional file servers and that informational interoperability will be achieved using a networked information system infrastructure. The authors and others have proposed and implemented models of semantically organized information systems that utilize centrally stored and highly structured archival information to index, cross-reference, and retrieve diverse, Web-based data sets.
Transplantation and Gene Therapy: Combined Approaches for Repair of Spinal Cord Injury
Authors: Murray Marion , Fischer Itzhak
Published: April 2009

Motor and sensory functions are lost after spinal cord injury because neurons die or atrophy and axons fail to regenerate. Until fairly recently, it was believed that damaged neurons could not be replaced and injured axons could not regenerate, and, therefore, functions dependent on injured neurons could not be recovered. We now know that damaged neurons can be rescued by providing therapeutic factors or replaced by grafting. In addition, the adult CNS contains a population of precursor cells with a potential to generate new neural cells, whose numbers and composition can be modified by extrinsic factors. The pioneering studies of Aguayo demonstrated that CNS axons could regenerate in the right environment. Subsequent studies have revealed the identity of some of the inhibitory molecules in myelin and scar tissue, and we now have a better understanding of how the CNS environment can be modified to become more permissive to regeneration. Axons that regenerate must find an appropriate target, but it may not be essential to reestablish the precise topography for some functions to be restored. There are now new and promising strategies for delivery of therapeutic genes to protect neurons and to stimulate regeneration. The ability to engineer cells by gene therapy combines the therapeutic values of cell transplantation and gene delivery. These remarkable developments from many disciplines have generated a new level of optimism in the search for a cure for CNS injury and in particular spinal cord injury. In this review, the authors summarize recent progress in these strategies and some of the challenges that remain in elucidating the most efficacious protocols for rescuing injured neurons, encouraging regeneration of their axons, and promoting recovery of function.
Functional MRI and Its Applications to the Clinical Neurosciences
Authors: Detre John A. , Floyd Thomas F.
Published: April 2009

Functional magnetic resonance imaging (fMRI) is an emerging methodology for studying regional brain function in vivo at relatively high spatial and temporal resolution. Because MRI methods are comparatively inexpensive and entirely noninvasive, fMRI has rapidly become one of the most popular approaches for brain mapping in cognitive and systems neuroscience. There has also been great interest in using fMRI to assist in clinical diagnosis and management, with promising demonstrations of feasibility in a number of applications. Both resting and task-specific regional brain activity can be measured, primarily utilizing alterations in regional cerebral blood flow (CBF) as a surrogate marker for neural function. This article reviews the biophysical and physiological bases of fMRI and its applications to the clinical neurosciences, with particular attention to potential challenges of fMRI under pathophysiological conditions. Carefully controlled prospective evaluation of clinical fMRI in its various potential applications will be required for fMRI to be validated as a clinically useful tool. Because the technology for fMRI is widely available, its impact could be substantial.
Fast Kinetic Analysis of Ligand-Gated Ion Channels
Authors: Breitinger Hans-Georg
Published: April 2009

Ligand-gated ion channels mediate fast synaptic transmission in the central and peripheral nervous system and the neuromuscular junction. Their common principle of function is the conversion of a chemical signal—neurotransmitter binding—into an electrical signal, i.e., an ion influx into the postsynaptic cell. The transient nature of this signal requires experimental setups that provide adequate temporal resolution and the use of transient kinetic analysis rather than equilibrium methods for a correct description of receptor function. Although the highly specialized geometry of a synapse that allows very rapid delivery of neurotransmitter is difficult to mimic in an experimental system, a variety of techniques for rapid kinetic analysis are available, making it possible to determine at least some steps of receptor function with sufficient accuracy. This article provides an overview of strategies and methods of fast ligand application and kinetic analysis using whole-cell and single channel patch clamp.
Neuregulins and the Shaping of Synapses
Authors: Ozaki Miwako
Published: April 2009

In developing and mature neural circuits, neural electrical activity controls the correct formation of connections and their state. Neuregulins (NRGs) mediate between the electrical neural activity and molecular components by regulating the expression of ion channel receptors or transmitter release in synapses. Furthermore, NRGs may be signaling factors involved in tuning locomotion or other higher functions by coordinating excitatory and inhibitory neurons.
Nerve Injury-!Induced Pain in the Trigeminal System
Authors: Fried K. , Bongenhielm U. , Boissonade F. M. , Robinson P. P.
Published: April 2009

This article reviews some recent findings on peripheral mechanisms related to the development of oro-facial pain after trigeminal nerve injury. Chronic injury-induced oro-facial pain is not in itself a life-threatening condition, but patients suffering from this disorder undoubtedly have a reduced quality of life. The vast majority of the work on pain mechanisms has been carried out in spinal nerve systems. Those studies have provided great insight into mechanisms of neuropathic spinal pain, and much of the data from them is obviously relevant to studies of trigeminal pain. However, it is now clear that the pathophysiology of the trigeminal nerve (a cranial nerve) is in many ways different to that found in spinal nerves. Whereas some of the changes seen in animal models of trigeminal nerve injury mimic those occurring after spinal nerve injury (e.g., the development of spontaneous activity from the damaged axons), others are different, such as the time-course of the spontaneous activity, some of the neuropeptide changes in the trigeminal ganglion, and the lack of sprouting of sympathetic terminals in the ganglion. Recent findings provide new insights that help our understanding of the etiology of chronic injury-induced oro-facial pain. Future investigations will hopefully explain how data gained from these studies relate to clinical pain experience in man and should enable the rapid development of new therapeutic regimes.
Gait and Balance Dysfunction: A Model of the Interaction of Age and Disease
Authors: Wolfson Leslie
Published: April 2009

This article reviews age-associated changes in gait, balance, and sensorimotor function and contrasts them to the changes that occur as a result of disease. Strength peaks in the mid-20s but declines only modestly until the fifth decade, after which there is rapid decline. All aspects of sensory function diminish with age, resulting in modest sensory changes in older patients. Gait speed is stable until the seventh decade and thereafter slows modestly. Age-related changes in the balance of older persons result in an effective response that meets routine needs but may be ineffective under demanding circumstances capable of producing response. Thus, these modest age-related decrements may be an element in the increased incidence of falls in older people. The loss of function caused by disease is of greater magnitude as well as being superimposed on that caused by age and thus may lead to a failure of mobility. Neurologic diseases that impair sensorimotor function compromise mobility in a manner consistent with the deficits that they produce. In mobility dysfunction caused by white matter lesions, the gait/balance abnormalities may not have unique clinical features, making diagnosis difficult. We used quantitative MRI to study the brains of older subjects with mobility impairment. The volume of white matter lesions in mobility-impaired subjects was double that of controls and was unrelated to increasing age, suggesting that white matter lesions are a disease-related rather than an age-related occurrence. We also used stance perturbation evoked potentials to demonstrate delayed conduction in some mobility-impaired older subjects. Prolonged sensory conduction may contribute to maladaptive balance and thus may be useful for diagnosis. Contemporary imaging and neurophysiology thus provides insight into the pathophysiology of mobility impairment and allows for more accurate diagnosis.
Sex Hormones in Experimental Autoimmune Encephalomyelitis: Implications for Multiple Sclerosis
Authors: Voskuhl Rhonda R. , Palaszynski Karen
Published: April 2009

For decades, it has been known that females are more susceptible than males to multiple sclerosis (MS). It has also long been appreciated that during late pregnancy there is a decrease in MS disease activity. Interestingly, these two observations have also been made in an extensively used animal model for MS, experimental autoimmune encephalomyelitis (EAE) in SJL mice. Female mice are more susceptible to disease than male mice, and there is an improvement in disease during late pregnancy. In this review, the role of sex hormones in each of these two observations is characterized in this EAE model using castration and exogenous hormone treatment strategies. The gender difference in EAE susceptibility is due primarily to a protective effect of testosterone in male mice. The decrease in disease severity during late pregnancy appears to be due at least in part to high levels of estriol, which characterize this time period.
Book Review: Reward Signaling by Dopamine Neurons
Authors: Schultz Wolfram
Published: April 2009

Dopamine projections from the midbrain to the striatum and frontal cortex are involved in behavioral reactions controlled by rewards, as inferred from deficits in parkinsonism, schizophrenia, and drug addiction. Recent experiments have shown that dopamine neurons are not directly modulated in relation to movements. Rather, they appear to code the rewarding aspects of environmental stimuli. They show short, phasic increases of activity following primary food and liquid rewards (“unconditioned stimuli”) and conditioned, reward-predicting stimuli of visual, auditory, and somatosensory modalities. They also display smaller activation-depression sequences after stimuli resembling rewards and after novel or particularly intense stimuli. Rewards are only reported as far as they occur differently than predicted. According to learning theories, a “prediction error” message may constitute a powerful teaching signal for behavior and learning. The phasic reward message is different from the more tonic enabling function of dopamine that is deficient in Parkinson’s disease, indicating that dopamine neurons subserve different functions at different time scales. Neurons in other brain structures, such as the striatum, orbitofrontal cortex, and amygdala, code the quality, quantity, and preference of rewards. The dopamine reward prediction error signal may cooperate with these reward perception signals during the learning and performance of behavioral reactions to motivating environmental stimuli.
Recruitment of Synaptic Molecules during Synaptogenesis
Authors: Ziv Noam E.
Published: April 2009

The glutamatergic synapse is the main type of excitatory synapse in the mammalian brain. The formation of each glutamatergic synapse is associated with the recruitment of numerous (probably hundreds) different molecules and their assimilation into functional assemblies. Intense research has revealed the identity of many of these molecules, provided information as to interactions they are involved in, and offered clues as to their roles in synaptic function. Recent work has also begun to shed light on fundamental mechanisms underlying molecule recruitment to developing glutamatergic synapses. Current data indicate that the formation of presynaptic active zones—sites of neurotransmitter release—may be realized by the insertion of precursor vesicles containing multiple active zone components, possibly in pre-assembled form. The assembly of the postsynaptic reception apparatus, on the other hand, seems to occur via the sequential recruitment of molecules to the postsynaptic membrane and their assimilation in situ. Several molecules and mechanisms have been identified that display a capacity for inducing pre- or postsynaptic differentiation. These exciting findings are starting to provide a rudimentary framework for understanding key processes underlying the formation of glutamatergic synaptic connections.
The Central Noradrenaline System and Memory Consolidation
Authors: Kobayashi Kazuto , Yasoshima Yasunobu
Published: April 2009

Long-term memory requires de novo protein synthesis and gene expression, which are mediated by certain intracellular signaling pathways. The noradrenaline (NA) system in the CNS is involved in a wide variety of neurological and psychological functions. In addition to previous pharmacological studies, a recent molecular genetic approach provides behavioral evidence for an essential role of the central NA system in long-term memory formation, particularly in memory consolidation. The potential cellular and molecular mechanisms underlying memory formation mediated by NA are discussed.
Book Review: On the Function of Dendritic Spines
Authors: Yuste Rafael , Majewska Ania
Published: April 2009

Dendritic spines occupy a strategic position in the central nervous system, yet their function is still under debate. Over the past decades, many hypotheses have been put forward to explain the specific function of spines. Recently, imaging experiments have demonstrated that spines compartmentalize calcium, a role that appears necessary for input-specific forms of synaptic plasticity. In addition, it has been discovered that spine morphology is plastic over fast time scales and can be controlled by specific biochemical pathways. Also, several aspects of the spine’s morphology appear to be intricately linked to its function. The authors review these recent data and incorporate them into a model for the function of dendritic spines in CNS circuits. In their proposal, spines serve to specifically connect sparse inputs and therefore minimize the wiring necessary in the CNS while maximizing connectivity. By virtue of the same design, spines isolate inputs and thus implement local learning rules. These rules appear only necessary with sparse inputs so these two functions are intimately related. Spines therefore would play a crucial circuit role, remarkably analogous to synaptic matrix elements of associative neural networks. This model highlights the economical, yet elegant, design of CNS circuits.
Book Review: Neural Network Models of Schizophrenia
Authors: Hoffman Ralph E. , Mcglashan Thomas H.
Published: April 2009

There is considerable neurobiological evidence suggesting that schizophrenia is associated with reduced corticocortical connectivity. The authors describe two neural network computer simulations that explore functional consequences of these abnormalities. The first utilized an “attractor” neural network capable of content-addressable memory. Application of a pruning rule that eliminated weaker connections over longer distances produced functional fragmentation and the emergence of localized, “parasitic” attractors that intruded into network dynamics. These pathologies generally were expressed only when input information was ambiguous and provide models for delusions and cognitive disorganization. A second neural network simulation examined effects of corticocortical pruning in a speech perception network. Excessive pruning caused the network to produce percepts spontaneously, that is, in the absence of inputs, thereby simulating hallucinations. The “hallucinating” network also demonstrated subtle impairments in narrative speech perception. A parallel study of human patients found similar impairments when comparing hallucinating patients with nonhallucinating patients. In addition, the authors have used transcranial magnetic stimulation (TMS) to directly probe speech perception neurocircuitry in patients with these hallucinations. As predicted by the neural network model, the authors confirmed that “suppressive” low-frequency TMS reduces auditory hallucinations. Neural network simulations provide empirically testable concepts linking phenomenological, cognitive, and neurobiological findings in schizophrenia.
Cushing’s Contributions to Neuroscience, Part 2: Cushing and Several Dwarfs
Authors: Savitz Sean I.
Published: April 2009

Harvey Cushing revolutionized modern neurosurgery and pioneered the field of neuroendocrinology. This second of a two-part series on Harvey Cushing’s contributions to neuroscience discusses his pivotal discoveries of the function and clinical disorders of the anterior pituitary. A review of his 20-year obsession with the pituitary reveals Cushing’s ingenuity, keen sense of observation, and persistent stubborness. His enthusiasm to test his ideas, however, led to risky experimentation. Despite his foibles, his work opened up new frontiers of research for a number of investigators, whose efforts resulted in the identification of specific pituitary hormones, the hypothalamic regulation of the pituitary, and the practical applications of endocrinology.
Caspases in Huntington’s Disease
Authors: Mejia René O. Sanchez , Friedlander Robert M.
Published: April 2009

Huntington’s disease (HD) is an autosomal dominant condition, resulting from a mutation in huntingtin (htt). Htt is a novel protein, and its normal function is at present not well understood. Nuclear translocation of mutant htt in vitro up-regulates expression of the cell death gene caspase-1. We have demonstrated in a transgenic HD mouse model that caspase-1 and caspase-3 are transcriptionally up-regulated and activated. Underscoring the relevancy of these findings, recent results suggest that caspase-1 is activated in brains of humans with HD. Caspase activation results in the proteolytic cleavage of key cellular targets, including htt, leading to cell dysfunction. Caspase activation leading to cell dysfunction and death correlates with disease progression. In HD-transgenic mice, caspase inhibition resulted in a delayed onset of symptoms, a slowed progression, and prolonged survival. Caspase inhibition is a therapeutic strategy that merits evaluation in humans with HD.
Book Review: Galanin: An Endogenous Anticonvulsant?
Authors: Mazarati Andrey , Langel ülo , Bartfai Tamas
Published: April 2009

Galanin is a neuroendocrine peptide involved in the regulation of feeding, pain, sexual behavior, learning, and memory. The recent discovery, that galanin antagonized excitatory glutamatergic neurotransmission in the hippocampus, provided a rationale for its possible antiepileptic effects. Here we summarize the data on the effects of galanin on seizure activity in several animal models of epilepsy. Pharmacological and molecular biological evidence suggest potent anticonvulsant effects of galanin. Exogenous administration of galanin receptor agonists attenuated seizures, whereas application of galanin receptor antagonists potentiated seizure expression. Genetically engineered mice, with either deletion or overexpression of galanin gene, showed altered resistance to seizures, which was in direct correlation with galanin gene expression. Possible mechanisms of the anticonvulsant action of galanin include its effects on synaptic potentiation in hippocampal circuits and inhibition of the release of the excitatory neurotransmitter glutamate from principal hippocampal neurons.
Teaching Neuroscience through Web Adventures: Adolescents Reconstruct the History and Science of Opioids
Authors: Miller Leslie , Schweingruber Heidi , Oliver Robert , Mayes Janice , Smith Donna
Published: April 2009

New technological and cultural developments surrounding adolescents’ use of the World Wide Web offer an opportunity for turning aspects of the Internet gaming phenomenon to the advantage of neuroscience education. Specifically, an experimental project to transmit aspects of problem-based learning and the National Science Standards through an interactive Web adventure is reported here. The Reconstructors is an episodic Web-based adventure series entitled Medicinal Mysteries from History. It is funded by the National Institute on Drug Abuse, and the first series focuses on opioids. It was created with the input of middle school students and teachers. Through the use of multimedia technologies, middle school students enter a futuristic world in which they become “reconstructors,” members of an elite scientific unit charged with recovering lost medical knowledge about analgesic drugs. Two of the four episodes have been evaluated through a comprehensive review process involving middle school students, teachers, neuroscience researchers, and clinicians. Analysis of the pretest and posttest scores demonstrated significant knowledge gain that validly can be attributed to use of the game. These data provide evidence that science content can be transmitted through innovative online techniques without sacrificing compelling content or effective pedagogical strategies.
Book Review: Iron and Parkinson’s Disease
Authors: Wolozin Benjamin , Golts Natalie
Published: April 2009

Multiple studies implicate iron in the pathophysiology of Parkinson’s disease (PD). In the brains of patients with PD, iron levels are elevated and the levels of iron-binding proteins are abnormal. Iron has been suspected to contribute to PD because Fe(II) is known to promote oxidative damage. Recent studies suggest that an additional mechanism by which iron might contribute to PD is by inducing aggregation of the α-synuclein, which is a protein that accumulates in Lewy bodies in PD.
Book Review: Cell Death in the Peripheral Nervous System: Potential Rescue Strategies
Authors: Windebank Anthony J. , Mcdonald Elizabeth
Published: April 2009

Neuronal death occurs in many diseases of the peripheral nervous system including genetic, developmental, metabolic, degenerative, and toxic disorders. Specific diseases are mediated by one or several interlinked death-initiating pathways. These may involve oxidative stress, excitotoxicity, membrane disruption, loss of calcium homeostasis, DNA damage, trophic factor loss, or aberrant entry into the cell cycle. The death initiators activate two major final common pathways that lead to cell death. Necrosis is a catastrophic loss of ionic integrity caused by membrane disruption or loss of energy supply. Apoptosis is an endogenous programmed cell death pathway normally active in development and tissue homeostasis. It leads to orderly disassembly of the cell. Advances in understanding of the pathways from specific disease to neuronal death are leading to new strategies designed to prevent death and treat diseases of the nervous system.
Regulation of the Cell Cycle in Normal and Pathological Glia
Authors: Stevens Beth , Fields R. Douglas
Published: April 2009

Precise regulation of the glial cell cycle is essential during nervous system development and in response to injury, whereas disruption of cell cycle control is associated with malignant glial tumors and other nervous system diseases. The Ras signaling pathway plays a central role in regulating the mammalian cell cycle, and uncontrolled Ras signaling has been implicated in a wide range of human cancers, including malignant gliomas. Recent studies in glia have demonstrated that activation of Ras can either induce or inhibit proliferation through complex interactions among downstream signaling pathways impinging on cell cycle regulatory proteins. Studies in Schwann cells have begun to delineate the pathways by which Ras regulates the cell cycle in normal and pathological glia, and have identified promising targets for therapeutic intervention in the treatment of PNS and CNS malignant glial tumors.
Do You Know Your Brain? A Survey on Public Neuroscience Literacy at the Closing of the Decade of the Brain
Authors: Herculano-Houzel Suzana
Published: April 2009

What does the public know about the developments offered by brain research? What factors influence public neuroscience literacy? What issues need to be emphasized to the public? To address these questions, a survey was conducted using a questionnaire with 95 assertions, answered by indicating yes, no, or I don’t know. The opinions of 35 senior neuroscientists and 2158 members of the public of Rio de Janeiro were heard on issues such as the mind-brain relationship, the senses, learning, and memory. The incidence of “correct” answers among the public improved the most with schooling, followed by reading of popular science magazines and of newspapers. An analysis of the responses to each assertion revealed which themes are well- or poorly known to the public. The results attest for the importance of popular scientific communication and indicate issues on which communication efforts should be concentrated in order to increase public awareness about the brain.
Review: Protein Kinase Signal Transduction Cascades in Mammalian Associative Conditioning
Authors: Selcher Joel C. , Weeber Edwin J. , Varga Andrew W. , Sweatt J. David , Swank Michael
Published: April 2009

One of the most intriguing and intensely studied questions facing contemporary neuroscientists involves the elucidation of the physiological mechanisms that underlie learning and memory. Recent advances have given us a much more detailed understanding of the signal transduction mechanisms subserving learning in the intact animal. One fact that has become clear is that activation of protein kinases and phosphorylation of their downstream effectors play a critical role. Four protein kinase cascades have garnered considerable attention in the study of information storage at both the synaptic and behavioral levels: Ca++/phospholipid-dependent protein kinase (PKC), Ca++/calmodulin-dependent protein kinase II (CaMKII), cAMP-dependent protein kinase (PKA), and extracellular signal-regulated kinase (ERK). This review will concentrate on studies of two behavioral tasks, conditioned fear and conditioned taste aversion, that provide evidence for the involvement of these kinase systems in associative learning. The authors will also examine a number of potential kinase substrates and how each could participate in the formation of long-term memories.
Review: Epilepsy as an Example of Neural Plasticity
Authors: Scharfman Helen E.
Published: April 2009

Epilepsy is a devastating disease affecting more than 1% of the population. Yet, if one considers the neurobiological substrates of this disease, what is revealed is an array of phenomenon that exemplify the remarkable capacity for the brain to change its basic structure and function, that is, neural plasticity. Some of these alterations are transient and merely impressive for their extent, or for their robust nature across animal models and human epilepsy. Others are notable for their persistence, often enduring for months or years. As an example, the dentate gyrus, and specifically the principal cell of the dentate gyrus, the granule cell, is highlighted. This area of the brain and this particular cell type, for reasons that are currently unclear, hold an uncanny capacity to change after seizures. For those interested in plasticity, it is suggested that perhaps the best examples for studying plasticity lie in the field of epilepsy.
Book Review: Cortex Governs Multisensory Integration in the Midbrain
Authors: Stein Barry E. , Wallace Mark W. , Stanford Terrence R. , Jiang Wan
Published: April 2009

Neurons in the superior colliculus (SC), a prominent midbrain structure, are able to synthesize information from different senses. This synthesis plays an important role in determining whether SC-mediated orientation behaviors will be initiated. In some circumstances, multisensory integration in the SC is evident as a response that is significantly enhanced above that evoked by the most effective single-modality stimulus. It can sometimes even exceed the arithmetic sum of the single-modality responses. In other circumstances, multisensory integration is evident as response depression, an effect sometimes powerful enough to eliminate even robust single-modality responses. The conditions that produce multisensory enhancement also increase the probability of orientation responses, and those that produce multisensory response depression decrease the probability of orientation responses. Although one might posit that the capability to integrate cross-modal cues (and, in this case, alter overt behavior) would be evident in all neurons capable of responding to stimuli from two or more sensory modalities, this turns out to be incorrect. When descending influences from the cortex are temporarily inactivated, SC neurons are rendered unable to synthesize their multiple sensory inputs, and animals no longer show enhanced orientation responses. Nevertheless, the ability to respond to cues from multiple sensory modalities is retained at both the single neuron and behavioral levels. Two cortical areas have been implicated in controlling these midbrain processes: the anterior ectosylvian sulcus and the rostral lateral suprasylvian sulcus.
Book Review: Arrestin: Roles in the Life and Death of Retinal Neurons
Authors: Dolph Patrick J.
Published: April 2009

G protein-coupled receptors are a large family of signaling molecules that respond to a wide variety of extracellular stimuli. The receptors relay the information encoded by the ligand through the activation of heterotrimeric G proteins and intracellular effector molecules. To ensure the appropriate regulation of the signaling cascade, it is vital to properly inactivate the receptor. This inactivation is achieved, in part, by the binding of a soluble protein, arrestin, which uncouples the receptor from the downstream G protein. In addition to the inactivation of G protein-coupled receptors, arrestins have also been implicated in the endocytosis of receptors and cross talk with other signaling pathways. Due to its central role in cellular signaling, misregulation or misfunction of arrestin can have dramatic affects on cell viability and have direct implications in human disease.
Book Review: Cortical Dysgenesis and Epilepsy
Authors: Roper Steven N. , Yachnis Anthony T.
Published: April 2009

Cortical dysgenesis (CD) describes a wide spectrum of brain anomalies that involve abnormal development of the cerebral cortex. There is a strong association between CD and epilepsy, and it comprises a significant proportion of children and adults whose epilepsy cannot be controlled with medications. There has been intense effort to define the relationship between CD and epilepsy so that more effective therapies can be devised. These efforts have ranged from detailed study of people with CD and epilepsy from a clinical standpoint to single-cell analysis of mRNA expression and postsynaptic receptor function. Animal models have also been developed to mimic certain aspects of CD in a situation when quantitative, controlled, and interventional experiments can be performed that would not be possible in a clinical setting. This review will give an overview of human CD syndromes and their causes, when possible, and describe some specific abnormalities in dysplastic cortex that may underlie its epileptogenic potential. It will also review several animal models of CD that have been studied mechanistically from the standpoint of epileptogenesis. In conclusion, some general trends will be proposed based on human and animal studies to encapsulate our current understanding of CD and how it causes epilepsy.
Book Review: Brain Specialization for Music
Authors: Peretz Isabelle
Published: April 2009

Music, like language, is a universal and specific trait to humans. Similarly, music appreciation, like language comprehension, appears to be the product of a dedicated brain organization. Support for the existence of music-specific neural networks is found in various pathological conditions that isolate musical abilities from the rest of the cognitive system. Cerebrovascular accidents, traumatic brain damage, and congenital brain anomalies can lead to selective disorders of music processing. Conversely, autism and epilepsy can reveal the autonomous functioning and the selectivity, respectively, of the neural networks that subserve music. However, brain specialization for music should not be equated with the presence of a singular “musical center” in the brain. Rather, multiple interconnected neural networks are engaged, of which some may capture the essence of brain specialization for music. The encoding of pitch along musical scales is likely such an essential component. The implications of the existence of such special-purpose cortical processes are that the human brain might be hardwired for music.
The Importance of Being Accountable
Authors: Irani Tracy , Sinclair Janas , O'malley Michelle
Published: April 2009

Constructs derived from Schlenker's triangle model of accountability were used to explore the relationship between perceptions of the accountability of government, industry, and the regulatory process and survey respondents' knowledge and attitude toward potential applications of plant genetic engineering. Regression analysis indicated that accountability was a better predictor of attitude toward potential applications of plant genetic engineering than respondents'level of knowledge. The results lend support to the argument that perceptions of accountability may play a significant role in consumer reactions to food biotechnology.
Advancing Science Communication
Authors: Treise Debbie , Weigold Michael F.
Published: April 2009

Scholars of science communication have identified many issues that may help to explain why science communication is not as “effective” as it could be. This article presents results from an exploratory study that consisted of an open-ended survey of science writers, editors, and science communication researchers. Results suggest that practitioners share many issues of concern to scholars. Implications are that a clear agenda for science communication research now exists and that empirical research is needed to improve the practice of communicating science
A Repertoire Approach to Environmental Information Channels
Authors: O'keefe Garrett J. , Ward Heather J. , Shepard Robin
Published: April 2009

This study supports the hypothesis that individuals use repertoires or groups of overlapping information channels for various purposes. Landowners in three Wisconsin counties were segmented into urbanites, rural nonfarmers, and farmers. The authors analyzed the frequencies with which these groups used different channels and repertoires of channels for information regarding conservation. For each of the populations, three repertoires emerged, although each included different channel arrays. Also, within each population, demographic and conservation-related predictors of repertoires varied.
Report: Tokyo Conference Sets Stage for a Third World Conference— and a New World Federation of Science Journalists
Authors: Cornell James
Published: April 2009

An international conference on science and technology journalism held in Tokyo in October 2001 (ICSTJ/Tokyo 2001) not only examined the challenges for science communicators in the next century but also served as a prelude for a Third World Conference to be held in Brazil in 2002 and laid the foundation for the creation of a World Federation of Science Journalists
A Survey of Science Content in U.S. Radio Broadcasting, 1920s through 1940s
Authors: Lafollette Marcel C.
Published: April 2009

During the formative years of radio broadcasting in the United States, information about science and medicine was initially packaged in formats common to educational settings, such as talks by individual scientists. Broadcasters eventually developed more appealing presentation approaches, adapting to the American listeners'expressed preference for drama and fast-paced entertainment, although the scientific community often hesitated to participate in such efforts to reach mass audiences. This survey of U.S. radio programming examines informational science series, broadcast from the 1920s through the 1940s, and the role played by key individuals, associations, and corporate underwriters. It identifies several trends pertinent to understanding the state of popular science communication today and raises questions for future research by historians of science communication.
Report: Science in a Connected World
Authors: Rogers Carol L.
Published: April 2009

Seminars, symposia, plenary lectures, special events, and a wide variety of other activities drew several thousand scientists, engineers, others interested in science, and science journalists to Boston, Massachusetts, 14-19 February 2002, for the 2002 Annual Meeting and Science Innovation Exposition of the American Association for the Advancement of Science. Included in this report are some of the highlights of the meeting.
Reliability of DSM-IV Symptom Ratings of ADHD
Authors: Solanto Mary V. , Alvir Jose
Published: April 2009

Objective: The objective of this study was to examine the intrarater reliability of DSM-IV ADHD symptoms. Method: Two-hundred-two children referred for attention problems and 49 comparison children (all 7-12 years) were rated by parents and teachers on the identical DSM-IV items presented in two different formats, the SNAP-IV and Conners’ Revised Questionnaires, at two closely spaced points in time. Results: For the combined sample, weighted kappa scores for intrarater agreement ranged from .30 (“fair”) to .77 (“good”) across symptoms. Kappa scores were good with respect to agreement on the DSM-IV criterion of endorsement of at least six symptoms in a given cluster for Inattention (.60 and .76, for parents and teachers, respectively) and Hyperactivity-Impulsivity (.72 and .75, respectively). Kappas for identification of cases as AD/HD or not AD/HD were good to excellent (.67 and .79 for parents and teachers, respectively). Classification as AD/HD or not AD/HD changed from the first to the second rating in 12% and 10% of cases rated parents and teachers, respectively. Conclusion: Reliability of individual ADHD symptoms appears to be suboptimal for clinical and research use and is improved, although less than ideal, at the levels of cluster endorsement and case classification. (J. of Att. Dis. 2009; 13(2) 107-116)
Accuracy of the DSM-Oriented Attention Problem Scale of the Child Behavior Checklist in Diagnosing Attention-Deficit Hyperactivity Disorder
Authors: Aebi Marcel , Winkler Metzke Christa , Steinhausen Hans-Christoph
Published: April 2009

Objective: The present study aimed at testing the Child Behavior Checklist (CBCL) including an adapted five-item DSM-Oriented Attention Problem Scale for predicting attention deficit hyperactivity disorders (ADHD). Methods: CBCL ratings were made both in a community sample ( N = 390) and an outpatient child psychiatric sample ( N = 392). Four different prediction models were analyzed in a community subsample ( n = 195) and an outpatient subsample ( n = 196) and cross-validated in two further subsamples of the same size. Results: The adapted DSM-Oriented Attention Problem Scale was superior to the original Attention Problem Scale in the identification of ADHD participants. A raw score of 5 to 6 on the reduced DSM-Oriented Attention Problem Scale was the best discriminator between cases and noncases. Conclusions: The adapted DSM-Oriented Attention Problem Scale of the CBCL is a useful screening instrument for ADHD with adequate diagnostic accuracy in community and outpatient samples. (J. of Att. Dis. 2010; 13(5) 454-463)