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Neural Structures (neural + structure)
Selected AbstractsInfant Intersubjectivity: Research, Theory, and Clinical ApplicationsTHE JOURNAL OF CHILD PSYCHOLOGY AND PSYCHIATRY AND ALLIED DISCIPLINES, Issue 1 2001Colwyn Trevarthen We review research evidence on the emergence and development of active " self-and-other " awareness in infancy, and examine the importance of its motives and emotions to mental health practice with children. This relates to how communication begins and develops in infancy, how it influences the individual subject's movement, perception, and learning, and how the infant's biologically grounded self-regulation of internal state and self-conscious purposefulness is sustained through active engagement with sympathetic others. Mutual selfother- consciousness is found to play the lead role in developing a child's cooperative intelligence for cultural learning and language. A variety of preconceptions have animated rival research traditions investigating infant communication and cognition. We distinguish the concept of " intersubjectivity ", and outline the history of its use in developmental research. The transforming body and brain of ahumanindividual grows in active engagement with an environment of human factors-organic at first, then psychological or inter-mental. Adaptive, human-responsive processes are generated first by interneuronal activity within the developing brain as formation of the human embryo is regulated in a support-system of maternal tissues. Neural structures are further elaborated with the benefit of intra-uterine stimuli in the foetus, then supported in the rapidly growing forebrain and cerebellum of the young child by experience of the intuitive responses of parents and other human companions. We focus particularly on intrinsic patterns and processes in pre-natal and post-natal brain maturation that anticipate psychosocial support in infancy. The operation of an intrinsic motive formation (IMF) that developed in the core of the brain before birth is evident in the tightly integrated intermodal sensory-motor coordination of a newborn infant's orienting to stimuli and preferential learning of human signals, by the temporal coherence and intrinsic rhythms of infant behaviour, especially in communication, and neonates' extraordinary capacities for reactive and evocative imitation. The correct functioning of this integrated neural motivating system is found to be essential to the development of both the infant's purposeful consciousness and his or her ability to cooperate with other persons' actions and interests, and to learn from them. The relevance of infants' inherent intersubjectivity to major child mental health issues is highlighted by examining selected areas of clinical concern. We review recent findings on postnatal depression, prematurity, autism, ADHD, specific language impairments, and central auditory processing deficits, and comment on the effcacy of interventions that aim to support intrinsic motives for intersubjective communication when these are not developing normally. [source] N-cadherin is regulated by gonadal steroids in adult sexually dimorphic spinal motoneuronsDEVELOPMENTAL NEUROBIOLOGY, Issue 4 2001Douglas A. Monks Abstract Gonadal steroids influence the morphology and function of neurons in the adult spinal cord through cellular and molecular mechanisms that are largely unknown. The cadherins are cell adhesion molecules that participate in the formation and organization of the CNS during embryonic development, and recent evidence suggests that the cadherins continue to regulate neural structure and function in adulthood. Using degenerate oligonucleotides coding conserved regions of the catenin-binding domain of classical cadherins in a RT-PCR cloning strategy, we identified several cadherin subtypes, the most frequently cloned being N-, E-, and R-cadherin, suggesting that these are the major classical cadherin subtypes present in the adult male rat lumbosacral spinal cord. We then examined cadherin expression levels of these cadherin subtypes under steroid conditions known to induce plastic changes in spinal motoneurons. Semiquantitative PCR revealed that mRNA levels of N-cadherin, but not E-cadherin or R-cadherin, are elevated in castrated rats treated with testosterone, 17,-estradiol, or dihydrotestosterone relative to castrate rats not treated with steroids. Immunolocalization of N-cadherin revealed that steroid treatment increased N-cadherin expression levels in functionally related neural populations whose morphology and function are regulated by steroids. These results suggest a role for N-cadherin in steroid-induced neuroplastic change in the adult lumbar spinal cord. © 2001 John Wiley & Sons, Inc. J Neurobiol 47: 255,264, 2001 [source] Does the cingulate cortex contribute to spatial conditional associative learning in the rat?HIPPOCAMPUS, Issue 7 2009Marie St-Laurent Abstract Rats with lesions to the anterior or posterior (retrosplenial) region of the cingulate cortex and rats with lesions that included both the anterior and posterior cingulate cortex were tested on a visual,spatial conditional task in which they had to learn to approach one of the two objects depending on the spatial context within which they were embedded. Lesions restricted to either the anterior or the retrosplenial cingulate region did not impair learning of this task which is known to be very sensitive to the effects of hippocampal lesions. Complete lesions of the cingulate cortex gave rise to only a minor retardation in learning. In contrast, lesions to the retrosplenial cortex impaired performance on a spatial navigation task and the classic radial maze. These results suggest that the retrosplenial portion of the cingulate region forms part of a hippocampal circuit underlying learning about spatial responses. The dissociation between the effects of lesions of the cingulate region on different classes of behavior known to be associated with hippocampal function suggests that, although this neural structure does play a role in an extended hippocampal circuit underlying spatial learning, its role in such learning may be a selective one. © 2009 Wiley-Liss, Inc. [source] Attachment style, affective loss and gray matter volume: A voxel-based morphometry studyHUMAN BRAIN MAPPING, Issue 10 2010Stefania Benetti Abstract Early patterns of infant attachment have been shown to be an important influence on adult social behavior. Animal studies suggest that patterns of early attachment influence brain development, contributing to permanent alterations in neural structure; however, there are no previous studies investigating whether differences in attachment style are associated with differences in brain structure in humans. In this study, we used Magnetic Resonance Imaging (MRI) and voxel-based morphometry (VBM) to examine for the first time the association between attachment style, affective loss (for example, death of a loved one) and gray matter volume in a healthy sample of adults (n = 32). Attachment style was assessed on two dimensions (anxious and avoidant) using the ECR-Revised questionnaire. High attachment-related anxiety was associated with decreased gray matter in the anterior temporal pole and increased gray matter in the left lateral orbital gyrus. A greater number of affective losses was associated with increased gray matter volume in the cerebellum; in this region, however, the impact of affective losses was significantly moderated by the level of attachment-related avoidance. These findings indicate that differences in attachment style are associated with differences in the neural structure of regions implicated in emotion regulation. It is hypothesized that early attachment experience may contribute to structural brain differences associated with attachment style in adulthood; furthermore, these findings point to a neuronal mechanism through which attachment style may mediate individual differences in responses to affective loss. Hum Brain Mapp, 2010. © 2010 Wiley-Liss, Inc. [source] Adaptive recurrent neural network control of biological wastewater treatmentINTERNATIONAL JOURNAL OF INTELLIGENT SYSTEMS, Issue 2 2005Ieroham S. Baruch Three adaptive neural network control structures to regulate a biological wastewater treatment process are introduced: indirect, inverse model, and direct adaptive neural control. The objective is to keep the concentration of the recycled biomass proportional to the influent flow rate in the presence of periodically acting disturbances, process parameter variations, and measurement noise. This is achieved by the so-called Jordan Canonical Recurrent Trainable Neural Network, which is a completely parallel and parametric neural structure, permitting the use of the obtained parameters, during the learning phase, directly for control system design. Comparative simulation results confirmed the applicability of the proposed control schemes. © 2005 Wiley Periodicals, Inc. Int J Int Syst 20: 173,193, 2005. [source] Steps towards a centralized nervous system in basal bilaterians: Insights from neurogenesis of the acoel Symsagittifera roscoffensisDEVELOPMENT GROWTH & DIFFERENTIATION, Issue 8 2010Henrike Semmler Due to its proposed basal position in the bilaterian Tree of Life, Acoela may hold the key to our understanding of the evolution of a number of bodyplan features including the central nervous system. In order to contribute novel data to this discussion we investigated the distribution of ,-tubulin and the neurotransmitters serotonin and RFamide in juveniles and adults of the sagittiferid Symsagittifera roscoffensis. In addition, we present the expression pattern of the neuropatterning gene SoxB1. Adults and juveniles exhibit six serotonergic longitudinal neurite bundles and an anterior concentration of serotonergic sensory cells. While juveniles show an "orthogon-like" arrangement of longitudinal neurite bundles along the anterior-posterior axis, it appears more diffuse in the posterior region of adults. Commissures between the six neurite bundles are present only in the anterior body region of adults, while irregularly distributed individual neurites, often interconnected by serotonergic nerve cells, are found in the posterior region. Anti-RFamide staining shows numerous individual neurites around the statocyst. The orthogon-like nervous system of S. roscoffensis is confirmed by ,-tubulin immunoreactivity. In the region of highest neurotransmitter density (i.e., anterior), the HMG-box gene SrSoxB1, a transcription factor known to be involved in neurogenesis in other bilaterians, is expressed in juvenile specimens. Accordingly, SoxB1 expression in S. roscoffensis follows the typical pattern of higher bilaterians that have a brain. Thus, our data support the notion that Urbilateria already had the genetic toolkit required to form brain-like neural structures, but that its morphological degree of neural concentration was still low. [source] Neuroanatomical substrates of social cognition dysfunction in autismDEVELOPMENTAL DISABILITIES RESEARCH REVIEW, Issue 4 2004Kevin Pelphrey Abstract In this review article, we summarize recent progress toward understanding the neural structures and circuitry underlying dysfunctional social cognition in autism. We review selected studies from the growing literature that has used the functional neuroimaging techniques of cognitive neuroscience to map out the neuroanatomical substrates of social cognition in autism. We also draw upon functional neuroimaging studies with neurologically normal individuals and individuals with brain lesions to highlight the insights these studies offer that may help elucidate the search for the neural basis of social cognition deficits in autism. We organize this review around key brain structures that have been implicated in the social cognition deficits in autism: (1) the amygdala, (2) the superior temporal sulcus region, and (3) the fusiform gyrus. We review some of what is known about the contribution of each structure to social cognition and then review autism studies that implicate that particular structure. We conclude with a discussion of several potential future directions in the cognitive neuroscience of social deficits in autism. © 2004 Wiley-Liss, Inc. MRDD Research Reviews 2004;10:259,271. [source] Differential expression of sphingosine-1-phosphate receptors 1-5 in the developing nervous systemDEVELOPMENTAL DYNAMICS, Issue 2 2009H. Meng Abstract Sphingosine-1-phosphate (S1P) binds to G protein,coupled receptors and can regulate a wide range of cellular functions. In a previous study, we isolated two key enzymes in the S1P pathway that were expressed in migrating neural crest cells. To determine if S1P receptors are present in neural crest cells or peripheral nervous system, we examine the expression patterns of S1P receptors (S1pr1-5) in mouse, and s1pr1 and s1pr3 in chick embryos. Here, we present a comprehensive expression analysis of these receptors using in situ hybridizations, which provide spatiotemporal information. We showed that S1pr2 was expressed in migrating cranial neural crest cells and enteric neurons. S1pr1 was prominently expressed in the neuroepithelium whereas S1pr4 and S1pr5 were in neurons at later stages. On the contrary, S1pr3 was predominantly detected in non-neuronal cells within and surrounding neural structures. We also described novel expression sites for S1P receptors in the developing nervous system. Developmental Dynamics 238:487,500, 2009. © 2009 Wiley-Liss, Inc. [source] Toward a neuro-developmental account of the development of declarative memoryDEVELOPMENTAL PSYCHOBIOLOGY, Issue 1 2008Patricia J. Bauer Abstract The study of the biological bases of memory has a long history. Based on research with patients with specific lesions and disease, animal models, and neuroimaging studies, the neural substrate that supports declarative memory in adults has been relatively well articulated. By contrast, studies of the neural bases of memory in development is in its infancy. Yet joint consideration of the processes involved in building a memory trace, and of the time course of development of the neural structures involved, has contributed to the generation of specific predictions regarding the sources of age-related change. Specifically, there are suggestions that in infancy and very early childhood, encoding and consolidation processes account for substantial age-related variance in long-term declarative memory. With development, the locus of age-related variability in the vulnerability of memory traces shifts to the later-stage processes of memory storage and retrieval. These insights are afforded by consideration of multiple levels of analysis, from the biological to the behavioral. © 2007 Wiley Periodicals, Inc. Dev Psychobiol 50: 19,31, 2008. [source] Ultrastructural and immunocytochemical observations of the nervous systems of three macrodasyidan gastrotrichsACTA ZOOLOGICA, Issue 3 2003R. Hochberg Abstract The nervous systems of three macrodasyidan gastrotrichs, Dactylopodola baltica, Macrodasys caudatus and Dolichodasys elongatus, were investigated using immunocytochemistry and electron microscopy. Labelling of neural structures against serotonin revealed the presence of two pairs of cerebral cells, a dorsal cerebral connective, and paired ventral nerve cords in D. baltica. In M. caudatus and D. elongatus serotonin immunoreactivity was present in a single pair of dorsal cerebral cells and the ventral nerve cords; the dorsal connective of D. elongatus was also immunoreactive to serotonin and acetylated ,-tubulin. The presence of paired, serotonin-like immunoreactive cells in D. baltica and other species may represent the plesiomorphic condition in Macrodasyida. The fine structure of the photoreceptors in D. baltica was also investigated to explore the potential ground pattern for eyes in the Macrodasyida. The pigmented photoreceptors of D. baltica contain a unicellular pigment cup, sheath cell and sensory receptor. The pigment cup contains numerous osmiophilic granules that presumably function to shield the eyes from downwelling light in the red part of the spectrum. Projecting into the pigment cup and sheath cell are numerous microvilli from a bipolar sensory cell. A single sensory cell may represent the plesiomorphic condition in Macrodasyida, with multiplication of sensory cells representative of more derived taxa. [source] Adult gaze influences infant attention and object processing: implications for cognitive neuroscienceEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 6 2005Vincent M. Reid Abstract Infants follow others' gaze toward external objects from early in ontogeny, but whether they use others' gaze in processing information about objects remains unknown. In Experiment 1, 4-month-old infants viewed a video presentation of an adult gazing toward one of two objects. When presented with the same objects alone a second time, infants looked reliably less at the object to which the adult had directly gazed (cued object). This suggests that the uncued object was perceived as more novel than the object previously cued by the adult's gaze. In Experiment 2, adult gaze was not directed towards any object. In this control experiment, infants looked at both objects equally in the test phase. These findings show that adult eye gaze biases infant visual attention and information processing. Implications of the paradigm for cognitive neuroscience are presented and the results are discussed in terms of neural structures and change over ontogeny. [source] Neuropsychological correlates of hippocampal and rhinal cortex volumes in patients with mesial temporal sclerosisHIPPOCAMPUS, Issue 8 2003Catherine E. O'Brien Abstract Considerable progress has been made toward understanding the function of the primate rhinal cortex, comprising the entorhinal (ErC) and perirhinal (PrC) cortices. However, translating animal models to human memory has been limited by the technological problems associated with characterizing neural structures in vivo. Functional correlates of hippocampal and rhinal cortex volume changes were examined in a sample of 61 temporal lobe epilepsy patients with mesial temporal sclerosis (MTS; 33 left, 28 right). Patients were administered the Wechsler Adult Intelligence Scale (revised or third edition), the Wechsler Memory Scale (revised or third edition), and a spatial maze task. Neuropsychological data, together with rhinal cortex and hippocampal volumes, collected in our earlier study (O'Brien CE, Bowden SC, Whelan G, Cook MJ, unpublished observations), were analyzed using multiple regression. The only significant predictor of verbal memory function was the difference score between the volume of left hippocampus and the left PrC. Spatial maze scores were predicted by the bilateral sum of ErC volume. The difference score between the left hippocampus and left PrC volumes was the most powerful predictor of verbal episodic memory. Right hippocampal volume was not a significant predictor of nonverbal episodic memory. Verbal and nonverbal semantic memory were not significantly predicted by any combination of rhinal cortex structures. This quantitative study suggests a lateralized or material-specific memory function for the left hippocampus and left PrC, in contrast to the bilateral role of the ErC. The left hippocampus and left PrC appear to act on verbal memory function through an opposing relationship. Finally, differentiation between hippocampal and subhippocampal components in terms of episodic and semantic memory, respectively, could not be supported by the current data. © 2003 Wiley-Liss, Inc. [source] Expression of synapsin and co-localization with serotonin and RFamide-like immunoreactivity in the nervous system of the chordoid larva of Symbion pandora (Cycliophora)INVERTEBRATE BIOLOGY, Issue 1 2010Ricardo Cardoso Neves Abstract. Cycliophora is one of the most recently described metazoan phyla and hitherto includes only two species: Symbion pandora and Symbion americanus. With a very complex life cycle, cycliophorans are regarded as an enigmatic group with an uncertain phylogenetic position, although they are commonly considered lophotrochozoan protostomes. In order to extend the database concerning the distribution of immunoreactive substances in the free-swimming chordoid larva of S. pandora, we investigated synapsin immunoreactivity using fluorescence-coupled antibodies in combination with confocal laserscanning microscopy. Moreover, we analyzed the co-localization patterns of synapsin, serotonin, and RFamide-like immunoreactivity in the chordoid larva by 3D imaging technology based on the confocal microscopy image stacks. Synapsin is expressed in large parts of the bilobed anterior cerebral ganglion including anterior and dorsal projections. Two pairs of ventral neurites run longitudinally into the larval body of which the inner pair shows only weak, scattered synapsin immunoreactivity. In addition, a lateral synapsin immunoreactive projection emerges posteriorly from each ventral longitudinal axon. Double immunostaining shows co-localization of synapsin and serotonin in the cerebral ganglion, the outer and the inner ventral neurites, and the anterior projections. Synapsin and RFamide-like immunoreactivity co-occur in the cerebral ganglion, the outer ventral neurites, and the dorsal projections. Accordingly, the cerebral ganglion and the outer ventral neurites are the only neural structures that co-express the two neurotransmitters and synapsin. The overall neuroanatomical condition of the cycliophoran chordoid larva resembles much more the situation of adult rather than larval life cycle stages of a number of spiralian taxa. [source] Investigation of a cyclopic, human, term fetus by use of magnetic resonance imaging (MRI)JOURNAL OF ANATOMY, Issue 5 2002D. Situ Abstract Using magnetic resonance imaging (MRI), the internal neural and craniofacial malformations of a cyclopic fetus are described. External facial features were characterized by a tubular proboscis situated above a single eye slit. The brain was recognized as ,pancake' type alobar holoprosencephaly (a condition where the undifferentiated telencephalon partially surrounds a monoventricle). Displacement of some bones that normally contribute to the orbit could be clearly discerned. Absence of neural structures (e.g. falx cerebri, corpus callosum) and missing components of the ethmoid bone indicated a midline deficit. This correlates with proposed theories of cyclopic embryopathy, which suggest that the prechordal plate and the neural crest cells are affected during the third week of gestation in cyclopia. [source] Ultrastructural Changes in Axons Following Exposure to Pulsed Radiofrequency FieldsPAIN PRACTICE, Issue 6 2009Serdar Erdine MD Abstract Pulsed radiofrequency (PRF) fields applied by an electrode to neural structures, such as the peripheral sensory nociceptor axons and dorsal root ganglion, are clinically effective in reducing pain and other neuropathic syndromes. However, a full understanding of the underlying mechanisms by which this occurs has not yet been clarified. In this study, PRF is applied to the afferent axons of the sciatic nerves of rats. A standard radiofrequency (RF) electrode and RF generator is used to apply the RF signal output to the sciatic nerve using standard PRF parameters that have been successfully used in clinical practice. The ultrastructure of the treated axons is observed after 10 days by electron microscopy. A control, sham application is simultaneously applied to the contralateral sciatic nerve to provide a statistical differential comparison. It is found that the internal ultrastructural components of the axons show microscopic damage after PRF exposure, including: abnormal membranes and morphology of mitochondria, and disruption and disorganization of microfilaments and microtubules. The damage appears to be more pronounced for C-fibers than for A-delta and A-beta fibers. The results are discussed in terms of internal electric field strengths and thermodynamic parameters. [source] On the nature and evolution of the neural bases of human languageAMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue S35 2002Philip Lieberman Abstract The traditional theory equating the brain bases of language with Broca's and Wernicke's neocortical areas is wrong. Neural circuits linking activity in anatomically segregated populations of neurons in subcortical structures and the neocortex throughout the human brain regulate complex behaviors such as walking, talking, and comprehending the meaning of sentences. When we hear or read a word, neural structures involved in the perception or real-world associations of the word are activated as well as posterior cortical regions adjacent to Wernicke's area. Many areas of the neocortex and subcortical structures support the cortical-striatal-cortical circuits that confer complex syntactic ability, speech production, and a large vocabulary. However, many of these structures also form part of the neural circuits regulating other aspects of behavior. For example, the basal ganglia, which regulate motor control, are also crucial elements in the circuits that confer human linguistic ability andreasoning. The cerebellum, traditionally associated with motor control, is active in motor learning. The basal ganglia are also key elements in reward-based learning. Data from studies of Broca's aphasia, Parkinson's disease, hypoxia, focal brain damage, and a genetically transmitted brain anomaly (the putative "language gene," family KE), and from comparative studies of the brains and behavior of other species, demonstrate that the basal ganglia sequence the discrete elements that constitute a complete motor act, syntactic process, or thought process. Imaging studies of intact human subjects and electrophysiologic and tracer studies of the brains and behavior of other species confirm these findings. As Dobzansky put it, "Nothing in biology makes sense except in the light of evolution" (cited in Mayr, 1982). That applies with as much force to the human brain and the neural bases of language as it does to the human foot or jaw. The converse follows: the mark of evolution on the brains of human beings and other species provides insight into the evolution of the brain bases of human language. The neural substrate that regulated motor control in the common ancestor of apes and humans most likely was modified to enhance cognitive and linguistic ability. Speech communication played a central role in this process. However, the process that ultimately resulted in the human brain may have started when our earliest hominid ancestors began to walk. Yrbk Phys Anthropol 45:36,62, 2002. © 2002 Wiley-Liss, Inc. [source] Endoscopic endonasal surgery for petrous apex lesionsTHE LARYNGOSCOPE, Issue 1 2009Adam M. Zanation MD Abstract Background: Endoscopic endonasal approaches to the ventral skull base are categorized based on their orientation in coronal and sagittal planes. For all of these approaches, the sphenoid sinus is the starting point, and provides orientation to important vascular and neural structures. Surgical approaches to the petrous apex include 1) a medial approach, 2) a medial approach with internal carotid artery (ICA) lateralization, and 3) a transpterygoid infrapetrous approach (inferior to the petrous internal carotid artery). The choice of a surgical approach depends on the relationship of the lesion to the internal carotid artery (medial or inferior), degree of medial expansion, and pathology. The purpose of this paper is to discuss the anatomic and technical features of endoscopic surgical approaches to the petrous apex, provide a new classification for approaches that focuses on the relationship of the lesion to the petrous internal carotid artery, and provide outcomes data on our first 20 endoscopic petrous apex approaches. Methods: A retrospective clinical outcome study of endoscopic petrous apex surgeries was performed at the University of Pittsburgh Medical Center. The medical records from patients with endoscopic endonasal approaches to isolated petrous apex lesions were reviewed for demographics, diagnoses, presentation, endoscopic approach, and clinical outcomes. Patients with lesions that extended into the petrous apex but were not isolated to the petrous apex were excluded (e.g., clival chordoma with extension into the petrous apex). Results: Twenty patients were included in the analysis: 13 inflammatory cystic lesions (9 cholesterol granulomas and four petrous apicitis) and 7 solid lesions. Chondrosarcoma was the most common solid petrous apex lesion in our series. Twelve of 13 cystic lesions were drained endoscopically (one surgery was aborted early in the series). All drained patients had resolution of presenting symptoms. One patient had closure of the outflow tract without return of symptoms and one patient had revision endoscopic drainage due to scarring and neo-osteogenesis and return of unilateral headache. No carotid injuries and no new cranial neuropathies occurred perioperatively. The advantages and limitations of the medial transsphenoidal approaches (with and without carotid mobilization) and the transpterygoid infrapetrous approach are discussed. Conclusions: The endoscopic endonasal approach to petrous apex lesions is safe and effective for appropriately selected patients in the hands of experienced endoscopic skull base surgeons. If offers advantages of removing the hearing and facial nerve risks from the transtemporal/transcranial approaches and allows for a larger and more natural drainage pathway into the sinuses. Laryngoscope, 119:19,25, 2009 [source] | ||||||||||||||||