Neurosciences Commons^™

Erratum: A Comparison Between Walsh And Autoregressive Derived Parameters Of Heart Rate Variability Spectra In Normal Subjects And Diabetics

Neurosciences

No abstract provided.

Can Meaningful Effective Connectivities Be Obtained Between Auditory Cortical Regions?, M S Gonçalves, D A Hall, Ingrid Johnsrude, M P Haggard

Brain and Mind Institute Researchers' Publications

Structural equation modeling (SEM) of neuroimaging data can be evaluated both for the goodness of fit of the model and for the strength of path coefficients (as an index of effective connectivity). SEM of auditory fMRI data is made difficult by the necessary sparse temporal sampling of the time series (to avoid contamination of auditory activation by the response to scanner noise) and by the paucity of well-defined anatomical information to constrain the functional model. We used SEM (i.e., a model incorporating latent variables) to investigate how well fMRI data in four adjacent cortical fields can be described as an …

New Procedures To Assess Executive Functions In Preschool Children, K. A. Espy, P. M. Kaufmann, M. L. Glisky, M. D. Mcdiarmid

Developmental Cognitive Neuroscience Laboratory: Faculty Publications

Executive functions are difficult to assess in preschool children, yet the preschool period is particularly important, both in the development of behavioral control and of the brain, particularly the prefrontal cortex. Several tasks were adapted from developmental and neuroscience literature and then administered to 98 preschool children (30-, 36-, 42-, 48- and 60-month age groups). Executive function task performance was related largely to age group, but not to sex or intelligence. These tasks, then, were sensitive in this age range and may be useful to delineate distinct cognitive profiles among preschool children with various neurological and developmental disorders.

Chemotherapeutic Cns Prophylaxis And Neuropsychologic Change In Children With Acute Lymphoblastic Leukemia: A Prospective Study, K. A. Espy, I. M. Moore, P. M. Kaufmann, J. H. Kramer, K. Matthay, J. J. Hutter

Developmental Cognitive Neuroscience Laboratory: Faculty Publications

OBJECTIVE: To determine whether prophylactic CNS chemotherapy for childhood acute lymphoblastic leukemia is associated with declines in neuropsychological abilities. METHODS: Growth curve analysis was used to examine neuropsychological outcome and treatment-related change in children (N = 30) who were treated at two childhood cancer centers. A comprehensive test battery was administered at baseline (8 months), 2, 3, and 4 years postdiagnosis (age at diagnosis M = 5.90 years, SD = 4.2C). RESULTS: Results indicated modest declines in arithmetic, visual motor integration, and verbal fluency. Intrathecal and systemic treatment was related to poorer visual motor integration at 4 years postdiagnosis and …

Ipsilesional Biases In Saccades But Not Perception After Lesions Of The Human Inferior Parietal Lobule, Tony Ro, Chris Rorden, Jon Driver, Robert Rafal

Publications and Research

We examined the effects of chronic unilateral lesions to either the inferior parietal lobe, or to the dorsolateral prefrontal cortex including the frontal eye fields (FEFs), upon human visual perception and saccades in temporal-order-judgment (TOJ) tasks. Two visual events were presented on each trial, one in each hemifield at various stimulus onset asynchronies (SOAs). In the saccade task, patients moved their eyes to whichever stimulus attracted gaze first. In the perceptual-manual task, they pressed a button to indicate which stimulus was perceived first. Frontal patients showed appropriate TOJs for visual targets in both tasks. Parietal patients showed appropriate TOJs in …

Discrimination Of Computer-Graphic Stimuli By Mice: A Method For The Behavioral Characterization Of Transgenic And Gene-Knockout Models., T J Bussey, L M Saksida, L A Rothblat

Brain and Mind Institute Researchers' Publications

An automated method is described for the behavioral testing of mice in an apparatus that allows computer-graphic stimulus material to be presented. Mice responded to these stimuli by making a nose-poke toward a computer monitor that was equipped with a touchscreen attachment for detecting responses. It was found that C57BL/6 mice were able to solve single-pair visual discriminations as well as 3-pair concurrent visual discriminations. The finding that mice are capable of complex visual discriminations introduces the possibility of testing mice on nonspatial tasks that are similar to those used with rats, monkeys, and humans. Furthermore, the method seems particularly …

The Structure And Biological Features Of Fibrinogen And Fibrin, Michael W. Mosesson, Kevin R. Siebenlist, David A. Meh

Biomedical Sciences Faculty Research and Publications

Fibrinogen and fibrin play important, overlapping roles in blood clotting, fibrinolysis, cellular and matrix interactions, inflammation, wound healing, and neoplasia. These events are regulated to a large extent by fibrin formation itself and by complementary interactions between specific binding sites on fibrin(ogen) and extrinsic molecules including proenzymes, clotting factors, enzyme inhibitors, and cell receptors. Fibrinogen is comprised of two sets of three polypeptide chains termed Aα, Bβ, and γ, that are joined by disulfide bridging within the N-terminal E domain. The molecules are elongated 45-nm structures consisting of two outer D domains, each connected to a central E domain by …

Neuromotor And Cognitive Development In Children With Cerebral Palsy In Relation To Neural Plasticity, Vaniecea Pollard

McCabe Thesis Collection

Infants with neurological disabilities, such as cerebral palsy (CP) and Down syndrome (DS), show severe delays in motor and cognitive development relative to chronological age. Involvement of neural plasticity as a treatment of such neurological disorders is increasingly being seen. Previous studies have found that interventions involving sensory linked motor performance have been critical in facilitating motor improvement. The purpose of this study was to compare self-initiated mobility in children with CP and DS. Three infants, ages 8, 9, and 22 months, with diagnoses of no CP, DS, and CP respectively, participated in the study. The infants were videotaped in …

Increased Mrna Expression For The Α1 Subunit Of The GabaA Receptor Following Nitrous Oxide Exposure In Mice, Lisa M. Johanek, William E. Cullinan, Linda K. Vaughn

Biomedical Sciences Faculty Research and Publications

The mechanisms by which nitrous oxide (N₂O) produces physical dependence and withdrawal seizures are not well understood, but both N₂O and ethanol exert some of their effects via the GABA_A receptor and several lines of evidence indicate that withdrawal from N₂O and ethanol may be produced through similar mechanisms. Expression levels of mRNA transcripts encoding several GABA_A receptor subunits change with chronic ethanol exposure and, therefore, we hypothesized that N₂O exposure would produce changes in mRNA expression for the α₁ subunit. Male, Swiss–Webster mice, 10–12 weeks of age, were …

Eye Position Sense Contributes To The Judgement Of Slant., F M James, S Whitehead, G K Humphrey, M S Banks, T Vilis

Brain and Mind Institute Researchers' Publications

We measured monocular judgements of the slant of a cube face while varying eye position in the absence of stereoscopic and external lighting cues. Errors were found to be small, only 10% on average of the cube's eccentricity. Two factors appear to have contributed approximately equally to this error: an underestimate of cube slant as seen by the eye and an underestimate of eye position. When prism adaptation altered the sensed eye position, the pattern of slant judgements changed to reflect the altered sense of eye position.

Cognitive Consequences And Central Nervous System Injury Following Treatment For Childhood Leukemia, I. M. Moore, K. A. Espy, P. Kaufmann, J. Kramer, K. Kaemingk, P. Miketova, N. Mollova, M. Kaspar, A. Pasvogel, K. Schram, W. Wara, J. Hutter, K. Matthay

Developmental Cognitive Neuroscience Laboratory: Faculty Publications

OBJECTIVES: To determine the relationship between membrane damage and intellectual and academic abilities in children with acute lymphoblastic leukemia (ALL) and pilot test a math intervention for children with ALL who were affected. DATA SOURCES: Research studies and review articles. CONCLUSIONS: Despite the prophylactic central nervous system (CNS) treatment for long-term disease-free survival, many children with ALL subsequently experience declines in intellectual and academic skills. IMPLICATIONS FOR NURSING PRACTICE: Improving academic abilities in children who have received CNS treatment is of high priority and may have longlasting implications on quality of life.

Prenatal Cocaine Exposure And Prematurity: Neurodevelopmental Growth, K. A. Espy, D. J. Francis, M. L. Riese

Developmental Cognitive Neuroscience Laboratory: Faculty Publications

The consequences of prematurity and prenatal cocaine exposure on early neurobehavior and physical growth were examined longitudinally in a sample of 20 cocaine-exposed and 20 nonexposed preterm neonates. The magnitude of the difference in physical growth acceleration related to prenatal cocaine exposure increased with increasing birth gestational age, whereas growth rate differences in irritability decreased. In contrast, prenatal cocaine exposure, independent of prematurity, was related to reduced attention skills at 36 wks conceptional age and increased rates of neurobehavioral change. The effects of prenatal cocaine exposure differed with respect to the degree of prematurity, depending on the nature of the …

Position Of Γ-Chain Carboxy-Terminal Regions In Fibrinogen/Fibrin Cross-Linking Mixtures, Kevin R. Siebenlist, David A. Meh, Michael W. Mosesson

Biomedical Sciences Faculty Research and Publications

There are conflicting ideas regarding the location of the carboxyl-terminal regions of cross-linked γ-chain dimers in double-stranded fibrin fibrils. Some investigators believe that the chains are always oriented longitudinally along each fibril strand and traverse the contacting ends of abutting fibrin D domains (“DD-long” cross-linking). Other investigations have indicated instead that the chains are situated transversely between adjacent D domains in opposing fibril strands (transverse cross-linking). To distinguish between these two possibilities, the γ dimer composition of factor XIIIa-cross-linked fibrin/fibrinogen complexes that had been formed through noncovalent D/E interactions between fibrinogen D domains and fibrin E domains was examined. Two …

Single Channel Properties And Regulated Expression Of Ca2+ Release-Activated Ca2+ (Crac) Channels In Human T Cells, Alla F. Fomina, Christopher M. Fanger, J. Ashot Kozak, Michael D. Cahalan

Neuroscience, Cell Biology & Physiology Faculty Publications

Although the crucial role of Ca²⁺ influx in lymphocyte activation has been well documented, little is known about the properties or expression levels of Ca²⁺ channels in normal human T lymphocytes. The use of Na⁺ as the permeant ion in divalent-free solution permitted Ca²⁺ release-activated Ca²⁺ (CRAC) channel activation, kinetic properties, and functional expression levels to be investigated with single channel resolution in resting and phytohemagglutinin (PHA)-activated human T cells. Passive Ca²⁺ store depletion resulted in the opening of 41-pS CRAC channels characterized by high open probabilities, voltage-dependent block by extracellular Ca²⁺ in …

Eye Position Signal Modulates A Human Parietal Pointing Region During Memory-Guided Movements., J F Desouza, S P Dukelow, J S Gati, R S Menon, R A Andersen, T Vilis

Brain and Mind Institute Researchers' Publications

Using functional magnetic resonance imaging, we examined the signal in parietal regions that were selectively activated during delayed pointing to flashed visual targets and determined whether this signal was dependent on the fixation position of the eyes. Delayed pointing activated a bilateral parietal area in the intraparietal sulcus (rIPS), rostral/anterior to areas activated by saccades. During right-hand pointing to centrally located targets, the left rIPS region showed a significant increase in activation when the eye position was rightward compared with leftward. As expected, activation in motor cortex showed no modulation when only eye position changed. During pointing to retinotopically identical …

Navigation-Related Structural Change In The Hippocampi Of Taxi Drivers, E A Maguire, D G Gadian, Ingrid Johnsrude, C D Good, J Ashburner, R S Frackowiak, C D Frith

Brain and Mind Institute Researchers' Publications

Structural MRIs of the brains of humans with extensive navigation experience, licensed London taxi drivers, were analyzed and compared with those of control subjects who did not drive taxis. The posterior hippocampi of taxi drivers were significantly larger relative to those of control subjects. A more anterior hippocampal region was larger in control subjects than in taxi drivers. Hippocampal volume correlated with the amount of time spent as a taxi driver (positively in the posterior and negatively in the anterior hippocampus). These data are in accordance with the idea that the posterior hippocampus stores a spatial representation of the environment …

Update - March 2000, Loma Linda University Center For Christian Bioethics

Update

In this issue:

-- National conference explores the future of faith-based health care
-- Ruth Macklin Judges Bioethical Relativism (Commentary)
-- Conditional Imortality and Cognitive Neuroscience
-- Clinical Ethics Consultation

Ethical Issues In Dementia, Peter J. Whitehouse

Faculty Scholarship

The growing number of individuals affected by dementia will intensify the ethical issues that emerge in clinical practice and research, issues early in disease relate to genetic testing, use of medications in mildly affected persons, and diagnostic disclosure. Research issues relate to appropriate informed consent processes, conflict of interests, and research design issues, such as the use of placebos and the use of biological tissues. In the later stages of disease concern about appropriate therapeutic goals and end-of-life care is appropriate.

Construct Validity Of The Continuous Recognition Memory Test, K. L. Fuchs, J. H. Hannay, W. M. Huckeba, K. A. Espy

Developmental Cognitive Neuroscience Laboratory: Faculty Publications

A principal factor analysis was performed on variables derived from a neuropsychological battery administered to 100 healthy young adults (aged 17-41 yrs) to investigate the construct validity of the Continuous Recognition Memory test (CRM). It was hypothesized that CRM "hits" and "false alarms" would load on different factors. The factors that emerged in the analysis were labeled Verbal Ability, Divided Attention, Attention to Visual Detail, Visuomotor Integration and Planning, and Learning and Memory. As expected, CRM hits had a significant loading on the Learning and Memory factor. However, CRM false alarms did not have a significant loading on the Divided …

Neuropsychologic Function In Toddlers Exposed To Cocaine In Utero: A Preliminary Study, K. A. Espy, P. M. Kaufmann, M. L. Glisky

Developmental Cognitive Neuroscience Laboratory: Faculty Publications

Patterns of neuropsychological performance on A-not-B, inhibition, motor, cognitive, language, and behavior tasks were examined in 34 toddlers--17 cocaine-exposed (CE) and 17 nonexposed (NE) controls. CE toddlers exhibited greater perseveration, less inhibition, poorer emotional regulation, and less task orientation relative to NE toddlers. Overall cognitive and language skills and motor impairment status were comparable among CE and NE toddlers. Differences in perseveration, emotional regulation, and task orientation between CE and NE toddlers remained significant after statistically controlling for overall cognitive skill. Prenatal cocaine exposure may impart selective vulnerability for deficits in executive function, inhibition, and emotional regulation in toddlers, perhaps …

Executive Functioning In Preschool Children: Performance On A-Not-B And Other Delayed Response Format Tasks, K. A. Espy, P. M. Kaufmann, M. D. Mcdiarmid, M. L. Glisky

Developmental Cognitive Neuroscience Laboratory: Faculty Publications

The A-not-B (AB) task has been hypothesized to measure executive/frontal lobe function; however, the developmental and measurement characteristics of this task have not been investigated. The present study examined performance on AB and comparison tasks adapted from developmental and neuroscience literature in 117 1.9-5.5 yr old preschool children. Age significantly predicted performance on AB, Delayed Alternation, Spatial Reversal, Color Reversal, and Self-Control tasks. A 4-factor analytic model best fit task performance data. AB task indices loaded on 2 factors with measures from the Self-Control and Delayed Alternation tasks, respectively. AB indices did not load with those from the reversal tasks …

The Predictive Use Of Event-Related Potentials In Language Development And The Treatment Of Language Disorders, Dennis L. Molfese, Victoria J. Molfese, K. A. Espy

Developmental Cognitive Neuroscience Laboratory: Faculty Publications

Attempts to relate what is currently known regarding the brain's involvement in language processing during the early years of life. The authors focus on the event related potential (ERP) as a means to study the neuroelectrical correlates of language in the brains of infants and children. After reviewing general information concerning ERPs and language, this presentation relates how neonatal ERP measures of phonetic discrimination predict later language and reading abilities.

Clinical Trials In Alzheimer Disease: Debate On The Use Of Placebo Controls, Peter J. Whitehouse

Faculty Scholarship

During the past 10 years, there has been a rapidly growing number of pharmaceutical industry-sponsored drug trials for treatment of Alzheimer disease (AD) and other neurodegenerative diseases. As public awareness and concerns about AD have grown, so has interest in developing drug therapies for retarding symptom progression, delaying onset, and ultimately curing the disease. Ethical debate on the use of placebo control trials in AD research has come of age in the United States with the availability of treatments approved by the Food and Drug Administration. The experts and the public agree that more effective therapies are necessary, and new …

Local And Global Stereopsis In The Horse., B Timney, K Keil

Brain and Mind Institute Researchers' Publications

Although horses have laterally-placed eyes, there is substantial binocular overlap, allowing for the possibility that these animals have stereopsis. In the first experiment of the present study we measured local stereopsis by obtaining monocular and binocular depth thresholds for renal depth stimuli. On all measures, the horses' binocular performance was superior to their monocular. When depth thresholds were obtained, binocular thresholds were several times superior to those obtained monocularly, suggesting that the animals could use stereoscopic information when it was available. The binocular thresholds averaged about 15 min arc. In the second experiment we obtained evidence for the presence of …

Perceptual-Mnemonic Functions Of The Perirhinal Cortex., Murray, Bussey

Brain and Mind Institute Researchers' Publications

It is widely acknowledged that the perirhinal cortex, located in the ventromedial aspect of the temporal lobe, is essential for certain types of memory in macaque monkeys. For example, removal of the perirhinal cortex yields severe impairments on tests of stimulus recognition and stimulus-stimulus association. There is considerable disagreement, however, about the most accurate way to characterize the function of the perirhinal cortex; some views emphasize a role in perception whereas others posit a role exclusively in declarative memory. In this article, we review recent findings from anatomical, physiological and ablation studies in monkeys, and discuss related findings obtained in …

Functionally Dissociating Aspects Of Event Memory: The Effects Of Combined Perirhinal And Postrhinal Cortex Lesions On Object And Place Memory In The Rat., T J Bussey, J L Muir, J P Aggleton

Brain and Mind Institute Researchers' Publications

Reciprocal interactions between the hippocampus and the perirhinal and parahippocampal cortices form core components of a proposed temporal lobe memory system. For this reason, the involvement of the hippocampus in event memory is thought to depend on its connections with these cortical areas. Contrary to these predictions, we found that NMDA-induced lesions of the putative rat homologs of these cortical areas (perirhinal plus postrhinal cortices) did not impair performance on two allocentric spatial tasks highly sensitive to hippocampal dysfunction. Remarkably, for one of the tasks there was evidence of a facilitation of performance. The same cortical lesions did, however, disrupt …

Staphylococcal Enterotoxin B Primes Cytokine Secretion And Lytic Activity In Response To Native Bacterial Antigens, K. M. Mason, T. D. Dryden, Nancy J. Bigley, P. S. Fink

Neuroscience, Cell Biology & Physiology Faculty Publications

Superantigens stimulate T-lymphocyte proliferation and cytokine production, but the effects of superantigen exposure on cell function within a complex, highly regulated immune response remain to be determined. In this study, we demonstrate that superantigen exposure significantly alters the murine host response to bacterial antigens in an in vitro coculture system. Two days after exposure to the superantigen staphylococcal enterotoxin B, splenocytes cultured with Streptococcus mutans produced significantly greater amounts of gamma interferon (IFN-gamma) and interleukin-12 than did sham-injected controls. The majority of IFN-gamma production appeared to be CD8(+) T-cell derived since depletion of this cell type dramatically reduced the levels …

The Location Of The Carboxy-Terminal Region Of Γ Chains In Fibrinogen And Fibrin D Domains, Michael W. Mosesson, Kevin R. Siebenlist, David A. Meh, Joseph S. Wall, James F. Hainfeld

Biomedical Sciences Faculty Research and Publications

Elongated fibrinogen molecules are comprised of two outer “D” domains, each connected through a “coiled-coil” region to the central “E” domain. Fibrin forms following thrombin cleavage in the E domain and then undergoes intermolecular end-to-middle D:E domain associations that result in double-stranded fibrils. Factor XIIIa mediates crosslinking of the C-terminal regions of γ chains in each D domain (the γXL site) by incorporating intermolecular ɛ-(γ-glutamyl)lysine bonds between amine donor γ406 lysine of one γ chain and a glutamine acceptor at γ398 or γ399 of another. Several lines of evidence show that crosslinked γ chains extend “transversely” between the strands of …

Identifying Swelling-Activated Channels From Ion Selectivity Patterns, Dan R. Halm

Neuroscience, Cell Biology & Physiology Faculty Publications

No abstract provided.

Developmental Expression Of Rat Target Of The Antiproliferative Antibody (Rtapa) Protein In The Brain, Clyde Dale Sullivan

Theses and Dissertations (ETD)

The present study defines the expression pattern of rTAPA (CD81) in the developing rat brain. rTAPA is a member of the tetramembrane spanning family of proteins, and like other members of this family, appears to be associated with the stabilization of cellular contacts. On immunoblots of the brain, rTAPA is present in higher levels than any other tissue examined: muscle, tendon, peripheral nerve, cartilage, liver, kidney, skin, and testicle. Immunohistochemical methods were used to define the distribution of rTAPA in the brain. This protein is expressed by ependyma, choroid plexus, astrocytes, and oligodendrocytes, and rTAPA is dramatically upregulated at the …