PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Models, Neurological”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 73 records · Page 4Linked to original sources
PubMed2001

Hypoxanthine-guanine phosphoribosyltransferase-deficiency produces aberrant neurite outgrowth of rodent neuroblastoma used to model the neurological disorder Lesch Nyhan syndrome.

Lesch Nyhan syndrome (LNS) manifests in bizarre and horrific neurological symptoms, the primary cause being a deficiency of the purine salvage enzyme, hypoxanthine-guanine phosphoribosyltransferase (HGPRT). How and why this enzyme deficiency leads to abnormal brain development is unknown. To investigate this phenomenon the present study was designed to examine if the growth of two HGPRT-deficient neuroblastomas, mouse N2aTG and rat B103-4C was different with respect to their corresponding control cell lines, N2a and B103. Data is provided showing that compared to control cell lines, HGPRT-deficient cells proliferated less and exhibited greater morphological complexity. If these abnormalities occur during neurogenesis of human HGPRT-deficient brain neurones, they could profoundly influence central nervous system development and thus, may form the aetiological basis for the symptoms of LNS.

Animals↗
PubMed1997

Early effects of iodine deficiency on radial glial cells of the hippocampus of the rat fetus. A model of neurological cretinism.

The most severe brain damage associated with thyroid dysfunction during development is observed in neurological cretins from areas with marked iodine deficiency. The damage is irreversible by birth and related to maternal hypothyroxinemia before mid gestation. However, direct evidence of this etiopathogenic mechanism is lacking. Rats were fed diets with a very low iodine content (LID), or LID supplemented with KI. Other rats were fed the breeding diet with a normal iodine content plus a goitrogen, methimazole (MMI). The concentrations of -thyroxine (T4) and 3,5,3'triiodo--thyronine (T3) were determined in the brain of 21-d-old fetuses. The proportion of radial glial cell fibers expressing nestin and glial fibrillary acidic protein was determined in the CA1 region of the hippocampus. T4 and T3 were decreased in the brain of the LID and MMI fetuses, as compared to their respective controls. The number of immature glial cell fibers, expressing nestin, was not affected, but the proportion of mature glial cell fibers, expressing glial fibrillary acidic protein, was significantly decreased by both LID and MMI treatment of the dams. These results show impaired maturation of cells involved in neuronal migration in the hippocampus, a region known to be affected in cretinism, at a stage of development equivalent to mid gestation in humans. The impairment is related to fetal cerebral thyroid hormone deficiency during a period of development when maternal thyroxinemia is believed to play an important role.

Animals↗
PubMed1989

[Psychiatry and the history of the localization of psychological functions].

The problem of the localisation of mental functions in the brain is historically analysed with special attention to its implications for psychiatry. The aim is not to discuss the historical details of the relationship between psychiatric models of madness and neurological models of brain functioning, but to cast some light on the broad intellectual and social framework within which the relationship became possible in the first place. It is argued that debates about the localizability of psychological processes are always more than just debates about structure-function correlation, and must in fact be ultimately understood as part of the much larger historical attempt within the natural sciences to "naturalize" man and his mind. Emphasis is laid on the extent to which different positions within the localisation debate have been influenced by unspoken social (political, religious) and philosophical factors, and questions are raised about the implications of this fact for modern neuropsychology and neuropsychiatry.

Brain↗
PubMed1977

[Pedagogical experience and learning models in neurologic semiology].

Programmed teaching of neurologic semiology, charted in agreement to subsequent learning in clinical neurology, is conceived. The basis of the pedagogic system consists of respecting the systems that bind physiologically among themselves. The goal is the creation of areas of comprehension, dramatizing common functions and signology. To know "all" is of less validity than to posses an engram prepared by key information. The anatomic physiology memory, previous to the course and the weekly partial evaluation, is considered useful. The problematic of the competitive test is analyzed and its negative and positive criterions are exposed. Anatomy, physiology, semiology and clinical neurology spun together are estimated to favor pedagogic goals redundantly.

Argentina↗
PubMedDate not supplied

[Protection against encephalitis in rats caused by a pathogenic strain of the Junin virus, using peripheral inoculation of an attenuated strain].

Argentine Hemorrhagic Fever manifests itself in man either subclinically or in hemorrhagic or neurological forms, mortality reaching 20%. Although Candid 1 strain is undergoing pilot trials, current therapy still resorts to convalescent serum administration. A neurological model was used to evaluate protection conferred by the attenuated XJC13 Junin virus strain. Newborn rats inoculated intraperitoneally (ip) prove resistant, whereas 8-12 day-old animals infected by intracerebral route with the XJ prototype strain suffer 100% mortality with neurological signs. The aim of this study was to achieve protection in this model and attempt to elucidate the mechanisms involved in resistance. It was observed that the longer the inoculation challenge interval, the greater was the survival percentage. In protected animals, brain viral titres were 3 log lower than in challenged controls, while XJC13 infected unchallenged controls presented low CNS values throughout. Neutralizing antibody levels were not significantly different in experimental versus challenged control groups, ruling out any secondary booster effect on protected rats. Neither the transfer of immunoserum nor of endogenous or exogenous interferon altered mortality. However, when splenocytes from rats infected 10 days previously were transferred prior to XJ challenge, survival was increased to 50%, but there was no gain in protection when cells were treated with antithymocyte serum plus complement. Consequently, protection in this neurological model can be attributed to a cellular immune response.

Animals↗
PubMed1982

Freud's "Project" and its relationship to psychoanalytic theory.

Sigmund Freud wrote the "Project for a Scientific Psychology" in 1895. Although the "Project" is essential a neurological model of mind, it will be shown that major concepts in psychoanalytic theory can be traced to this work. These include libido, primary process and the pleasure principle, secondary process and the reality principle, wish fulfillment, the ego, consciousness, and repression. The "Project" signifies a transition in Freud's thinking from a neurological to a psychological realm of discourse.

Consciousness↗
PubMed2001

Neuroanatomical basis for first- and second-order representations of bodily states.

Changes in bodily states, particularly those mediated by the autonomic nervous system, are crucial to ongoing emotional experience. A theoretical model proposes a first-order autoregulatory representation of bodily state at the level of dorsal pons, and a second-order experience-dependent re-mapping of changes in bodily state within structures such as cingulate and medial parietal cortices. We tested these anatomical predictions using positron emission tomography and a human neurological model (pure autonomic failure), in which peripheral autonomic denervation prevents the emergence of autonomic responses. Compared to controls, we observed task-independent differences in activity of dorsal pons and context-induced differences in cingulate and medial parietal activity in PAF patients. An absence of afferent feedback concerning autonomically generated bodily states was associated with subtle impairments of emotional responses in PAF patients. Our findings provide empirical support for a theory proposing a hierarchical representation of bodily states.

Aged↗
PubMed2006

[Effects of a shared decision making model in psychiatric and neurologic practice].

Involving patients in medical decisions is increasingly being advocated in medical fields other than psychiatry and neurology. A model of shared decision making might prove to be an ideal way of bridging the gap between patient-centred and evidence-based medicine. This report provides a survey of this shared decision making model and a discussion of its implications in the fields of mental health and neurology.

Adaptation, Psychological↗
PubMed2006

High-resolution large-scale mosaic imaging using multiphoton microscopy to characterize transgenic mouse models of human neurological disorders.

The thorough characterization of transgenic mouse models of human central nervous system diseases is a necessary step in realizing the full benefit of using animal models to investigate disease processes and potential therapeutics. Because of the labor- and resource-intensive nature of high-resolution imaging, detailed investigation of possible structural or biochemical alterations in brain sections has typically focused on specific regions of interest as determined by the researcher a priori. For example, Parkinson's disease researchers often focus imaging on regions of the brain expected to exhibit pathology such as the substantia nigra and striatum. Because of limitations in acquiring and storing high-resolution imaging data, additional data contained in the specimen is not usually acquired or disseminated/reported to the research community. Here we present a method of imaging large regions of brain at close to the resolution limit of light microscopy using a mosaic imaging technique in conjunction with multiphoton microscopy. These maps are being used to characterize several genetically modified animal models of neurological disease by filling the information "gap" among techniques such as magnetic resonance imaging and electron microscopic analysis.

Animals↗
PubMed2003

Towards a functional neural systems model of developmental stuttering.

UNLABELLED: This paper overviews recent developments in an ongoing program of brain imaging research on developmental stuttering that is being conducted at the University of Texas Health Science Center, San Antonio. This program has primarily used H(2)15O PET imaging of different speaking tasks by right-handed adult male and female persistent stutterers, recovered stutterers and controls in order to isolate the neural regions that are functionally associated with stuttered speech. The principal findings have emerged from studies using condition contrasts and performance correlation techniques. The emerging findings from these studies are reviewed and referenced to a neural model of normal speech production recently proposed by Jürgens [Neurosci. Biobehav. Rev. 26 (2002) 235]. This paper will report (1) the reconfiguration of previous findings within the Jürgens Model; (2) preliminary findings of an investigation with late recovered stutterers; (3) an investigation of neural activations during a treatment procedure designed to produce a sustained improvement in fluency; and (4) an across-studies comparison that seeks to isolate neural regions within the Jürgens Model that are consistently associated with stuttering. Two regions appear to meet this criterion: right anterior insula (activated) and anterior middle and superior temporal gyri (deactivated) mainly in right hemisphere. The implications of these findings and the direction of future imaging investigations are discussed. EDUCATIONAL OBJECTIVES: The reader will learn about (1) recent uses of H(2)15O PET imaging in stuttering research; (2) the use of a new neurological model of speech production in imaging research on stuttering; and (3) initial findings from PET imaging investigations of treated and recovered stutterers.

Adolescent↗
PubMed1986

On psychoanalysis and neuroscience: Freud's attitude to the localizationist tradition.

This study examines the relationship between psychoanalysis and neuroscience. It argues that the Project, the traditional starting-point for such an examination, provides few substantial links between Freud's neurological and psychoanalytic careers. The neurological model that the Project endorsed was not derived from Freud's formal neurological education, as has so often been assumed. It was based, instead, on the Jacksonian model that he developed in 'On aphasia' in 1891. 'On aphasia' appears to be the real 'missing link' between Freud's neurological and psychological years. The fundamental principles that it endorsed provided the framework within which psychoanalysis developed. After Freud's death, Luria developed the science of dynamic neuropsychology, which is based on the same fundamental neurological assumptions as 'On aphasia'. Dynamic neuropsychology approaches brain functioning in a way that would have been entirely acceptable to Freud. Considering the deep-rooted compatibility between Luria's neuropsychology and Freud's psychoanalysis, it would be beneficial for both sciences if they were to collaborate on issues of common interest. This makes Freud's lifelong ambition that psychoanalysis be rejoined with neuroscience a very real possibility.

Aphasia↗
PubMed1984

Delayed recovery of behavior after anesthesia in rats.

UNLABELLED: Early, complete recovery from general anesthesia is of importance for outpatients, in resuscitation research and in behavior testing of neonates. A model was designed to study behavior during the first week of recovery from anesthesia in rats, using two methods: spontaneous and unrestrained locomotor activity was tested and passive avoidance of electroshock was studied in a two session, one trial model. Neurologic deficit and ease of handling were also tested. After anesthesia with halothane 1-2% in N2O/O2 for 30 min, spontaneous activity was reduced, compared with unanesthetized rats, for up to at least 48 h. On day 6 post-anesthesia, locomotor activity was recovered, and, on days 4 and 5, passive avoidance was unchanged. Neurologic deficits were absent after the first hour of recovery and ease of handling was unchanged. CONCLUSION: Halothane and nitrous oxide have prolonged effects on locomotor behavior beyond the immediate post-anesthesia recovery period, at a time when neurologic deficit testing does not reveal any abnormalities. The model is suitable for the comparison of recovery from different anesthesia techniques in rats.

Anesthesia, General↗
PubMed2002

Neural substrates linking balance control and anxiety.

This communication provides an update of our understanding of the neurological bases for the close association between balance control and anxiety. New data suggest that a vestibulo-recipient region of the parabrachial nucleus (PBN) contains cells that respond to body rotation and position relative to gravity. The PBN, with its reciprocal relationships with the extended central amygdaloid nucleus, infralimbic cortex, and hypothalamus, appears to be an important node in a primary network that processes convergent vestibular, somatic, and visceral information processing to mediate avoidance conditioning, anxiety, and conditioned fear responses. Noradrenergic and serotonergic projections to the vestibular nuclei also have parallel connections with anxiety pathways. The coeruleo-vestibular pathway originates in caudal locus coeruleus (LC) and provides regionally specialized noradrenergic input to the vestibular nuclei, which likely mediate effects of alerting and vigilance on the sensitivity of vestibulo-motor circuits. Both serotonergic and nonserotonergic pathways from the dorsal raphe nucleus and the nucleus raphe obscurus also project differentially to the vestibular nuclei, and 5-HT(2A) receptors are expressed in amygdaloid and cortical targets of the PBN. It is proposed that the dorsal raphe nucleus pathway contributes to both (a) a tradeoff between motor and sensory (information gathering) aspects of responses to self-motion and (b) a calibration of the sensitivity of affective responses to aversive aspects of motion. This updated neurologic model continues to be a synthetic schema for investigating the neurological and neurochemical bases for comorbidity of balance disorders and anxiety disorders.

Animals↗
PubMed1992

[Model of a neurological theory of speech].

Recently, theories of neuronal computation in the brain have become detailed enough, so that it becomes possible to speculate about mechanisms underlying the production and perception of language. How many neurons are involved when we utter, or understand, a word, a phoneme, a phrase? In what neuronal form are the rules of grammar laid down in the synaptic network? To what does a morpheme correspond in the brain?

Aphasia↗