Cognitive Neuroscience Commons^™

Hyperhomocysteinemia As A Risk Factor For Vascular Contributions To Cognitive Impairment And Dementia, Brittani R. Price, Donna M. Wilcock, Erica M. Weekman

Physiology Faculty Publications

Behind only Alzheimer’s disease, vascular contributions to cognitive impairment and dementia (VCID) is the second most common cause of dementia, affecting roughly 10–40% of dementia patients. While there is no cure for VCID, several risk factors for VCID, such as diabetes, hypertension, and stroke, have been identified. Elevated plasma levels of homocysteine, termed hyperhomocysteinemia (HHcy), are a major, yet underrecognized, risk factor for VCID. B vitamin deficiency, which is the most common cause of HHcy, is common in the elderly. With B vitamin supplementation being a relatively safe and inexpensive therapeutic, the treatment of HHcy-induced VCID would seem straightforward; however, …

Astrocyte Activation And The Calcineurin/Nfat Pathway In Cerebrovascular Disease, Susan D. Kraner, Christopher M. Norris

Sanders-Brown Center on Aging Faculty Publications

Calcineurin (CN) is a Ca²⁺/calmodulin-dependent protein phosphatase with high abundance in nervous tissue. Though enriched in neurons, CN can become strongly induced in subsets of activated astrocytes under different pathological conditions where it interacts extensively with the nuclear factor of activated T cells (NFATs). Recent work has shown that regions of small vessel damage are associated with the upregulation of a proteolized, highly active form of CN in nearby astrocytes, suggesting a link between the CN/NFAT pathway and chronic cerebrovascular disease. In this Mini Review article, we discuss CN/NFAT signaling properties in the context of vascular disease and …

Ca2+, Astrocyte Activation And Calcineurin/Nfat Signaling In Age-Related Neurodegenerative Diseases, Pradoldej Sompol, Christopher M. Norris

Sanders-Brown Center on Aging Faculty Publications

Mounting evidence supports a fundamental role for Ca²⁺ dysregulation in astrocyte activation. Though the activated astrocyte phenotype is complex, cell-type targeting approaches have revealed a number of detrimental roles of activated astrocytes involving neuroinflammation, release of synaptotoxic factors and loss of glutamate regulation. Work from our lab and others has suggested that the Ca²⁺/calmodulin dependent protein phosphatase, calcineurin (CN), provides a critical link between Ca²⁺ dysregulation and the activated astrocyte phenotype. A proteolyzed, hyperactivated form of CN appears at high levels in activated astrocytes in both human tissue and rodent tissue around regions of amyloid and …

Electrophysiological Biomarkers Of Chemotherapy-Related Cognitive Impairment In Hematological Malignancy Patients, David E. Anderson

Theses & Dissertations

Multiple cancer populations frequently report cognitive impairment following treatment with chemotherapy agents (“chemo-brain”). Impaired neuropsychological performance is commonly reported in cognitive domains of attention and executive function. Understanding neural mechanisms underlying cognitive impairments is essential to developing prevention and rehabilitation strategies. Brain imaging studies frequently show chemotherapy-related impairments within the attentional control network, which is comprised of a constellation of cortical regions that govern reportedly impaired cognitive functions. In the current dissertation research, I developed a novel electrophysiology battery aimed at recording near-instantaneous neural activity within the attentional control network during cognitive task performance. Cancer patients diagnosed with hematological malignancy …

An Aged Canid With Behavioral Deficits Exhibits Blood And Cerebrospinal Fluid Amyloid Beta Oligomers, Clare Rusbridge, Francisco J. Salguero, Monique Antoinette David, Kiterie M. E. Faller, Jose T. Bras, Rita J. Guerreiro, Angela C. Richard-Londt, Duncan Grainger, Elizabeth Head, Sebastian G. P. Brandner, Brian Summers, John Hardy, Mourad Tayebi

Pharmacology and Nutritional Sciences Faculty Publications

Many of the molecular and pathological features associated with human Alzheimer disease (AD) are mirrored in the naturally occurring age-associated neuropathology in the canine species. In aged dogs with declining learned behavior and memory the severity of cognitive dysfunction parallels the progressive build up and location of Aβ in the brain. The main aim of this work was to study the biological behavior of soluble oligomers isolated from an aged dog with cognitive dysfunction through investigating their interaction with a human cell line and synthetic Aβ peptides. We report that soluble oligomers were specifically detected in the dog's blood and …

Baseline White Matter Hyperintensities And Hippocampal Volume Are Associated With Conversion From Normal Cognition To Mild Cognitive Impairment In The Framingham Offspring Study., Katherine J Bangen, Sarah R Preis, Lisa Delano-Wood, Philip A Wolf, David J Libon, Mark W Bondi, Rhoda Au, Charles Decarli, Adam M Brickman

Rowan-Virtua School of Osteopathic Medicine Departmental Research

INTRODUCTION: We examined associations between magnetic resonance imaging (MRI) markers of cerebrovascular disease and neurodegeneration with mild cognitive impairment (MCI) diagnosis at baseline and conversion from normal cognition to MCI at follow-up.

METHODS: Framingham Offspring participants underwent brain MRI and neuropsychological assessment at baseline (n=1049) and follow-up (n=561). Participants were classified at baseline and at follow-up as cognitively normal or MCI using sensitive neuropsychological criteria. White matter hyperintensity (WMH) volume, covert brain infarcts, hippocampal volume, and total cerebral brain volume were quantified.

RESULTS: Baseline measures of WMH and hippocampal volume were associated with MCI status cross-sectionally and also with conversion …

Under The Influence: An Interdisciplinary Approach To Psychedelics, Jody Roun

Master of Liberal Studies Theses

The following research will outline the effects of psychedelics from an interdisciplinary approach, which is to say that I will explore the neuroscience behind psychedelic drugs and how it relates to creativity, as a primary focus, while examining the role of additional points included along the way. The goal of this research, is to gain a deeper understanding of psychedelics and truly decipher what it means to be under the influence, as the most important goal of this human existence is to achieve understanding. The aforementioned is a point that great minds like Albert Einstein and Humphry Osmond impressed on …

Analysis Of Diagnostic, Preventive, And Disease-Modifying Therapeutic Measures Of Alzheimer’S Disease, Ghazal Habib Havoutis

HCNSO Student Capstones

Alzheimer’s disease (AD) is the most common late-onset neurodegenerative disorder and cause of dementia, characterized by the formation of neurofibrillary tangles and senile plaque deposits. The heterogeneous nature of the disease (both genetically and environmentally) makes it difficult to prevent or cure. Without prevention, the prevalence of AD is expected to triple by 2050. However, because the diagnosis of AD is usually preceded by years of cognitive impairment, early detection may aid in reducing prevalence. Thus, there is a need for validated diagnostic measures for early and improved diagnosis and prevention. In this review, current and ongoing classifiers of early …

Structural Dichotomy Of The Mind; The Role Of Sexual Neuromodulators, Ion G. Motofei, David L. Rowland

Journal of Mind and Medical Sciences

The mind (mental function) and sexuality represent two distinct environmental functions, but which are supported within the brain by a common (somatic-autonomic) neurobiological substrate. As a consequence, mental function takes on autonomic characteristics from the sexual-autonomic system (like autonomy, duality), while sexual function takes on features from mental functioning (such as lateralization). In this paper we discuss the lateralized action of two classes of sexual neuromodulators: hormones and pheromones. This process of lateralization is assimilated with the structural dichotomy of the mind.

A relatively similar process but related to informational dichotomy of the mind will be presented in a forthcoming …

Vitamin D Clinical Relevance In The Recovery From Traumatic Brain Injury Among The Military Population, Yuisa M. Colón

Honors Undergraduate Theses

Background: Traumatic brain injury (TBI) still remains a difficult disorder to treat. TBI has been associated to chronic neuroinflammation and a high risk for neurodegenerative disorders. Since 2001 between ten to twenty percent of all deployed military members have suffered a combat-related TBI. Nearly twenty to thirty percent of those will experience chronic cognitive, behavioral and somatic symptoms after suffering a TBI.
Methods: The objective of this review is to evaluate current literature examining vitamin D as a neurosteroid with protective properties and its clinical relevance after traumatic brain injury. Vitamin D is known to participate in neurobiological …

The Effects Of External Focus Of Attention Exercise Rehabilitation On Dual Task Walking In Parkinson's Disease, Eric N. Beck

Theses and Dissertations (Comprehensive)

Parkinson’s disease impairs control of well-learned movements, and therefore, individuals with Parkinson’s disease are forced to walk with greater conscious control. This causes difficulties while walking and completing a secondary task simultaneously (dual tasking), in that distractions from conscious control of walking increase the risk of falls and injury. Although, attention-based exercise may be a potential avenue to decrease the demands associated with walking in Parkinson’s disease. For example, an external focus of attention (on manipulated objects) has been found to recruit the networks that are important for walking with little conscious control (automatic control networks). In contrast, an internal …

Estrodial Effects On Age-Related Shifts In Learning And Memory: A Multiple Memory Systems Approach, Luis Castelan

Renée Crown University Honors Thesis Projects - All

Many findings from our lab and others suggest that circulating estrogens as well as estrogen replacement after ovariectomy influence cognitive performance. Young female rats trained during proestrus, when estrogens are high, or with acute estradiol (E2) administration after ovariectomy perform better on the hippocampus-sensitive place task but worse on the striatum-sensitive response task (Korol et al., 2004; Korol and Kolo, 2002). Behavioral neuroscience studies tend to use male rodent models to avoid the complexities of the female reproductive cycle, producing a gap in our knowledge about neural mechanisms of learning and memory in females. As a consequence, age-related effects of …

Influence Of Planning Resources On Gait Control In Parkinson’S Disease, Frederico P. Faria

Theses and Dissertations (Comprehensive)

Movement disturbances in individuals with Parkinson’s disease (PD) have been associated with difficulties to plan complex actions. Performance of simple and complex actions overloads resources for individuals with Parkinson’s disease (PD). However, it is unclear if central resources required to plan gait adjustments while walking exacerbate gait disturbances of patients with PD. More specifically, it is unclear how gait impairments, sensory processing, and the dopaminergic system influence the load on processing resources (e.g. cognitive load) during the planning of step modifications. In order to investigate the relative influence of these factors on cognitive load and its impact on gait control, …

Dynamics Of Alpha Control: Preparatory Suppression Of Posterior Alpha Oscillations By Frontal Modulators Revealed With Combined Eeg And Event-Related Optical Signal, Kyle E. Mathewson, Diane M. Beck, Tony Ro, Edward L. Maclin, Kathy A. Low, Monica Fabiani, Gabriele Gratton

Publications and Research

We investigated the dynamics of brain processes facilitating conscious experience of external stimuli. Previously, we proposed that alpha (8–12 Hz) oscillations, which fluctuate with both sustained and directed attention, represent a pulsed inhibition of ongoing sensory brain activity. Here we tested the prediction that inhibitory alpha oscillations in visual cortex are modulated by top–down signals from frontoparietal attention networks. We measured modulations in phase-coherent alpha oscillations from superficial frontal, parietal, and occipital cortices using the event-related optical signal (EROS), a measure of neuronal activity affording high spatiotemporal resolution, along with concurrently recorded EEG, while participants performed a visual target detection …

Direct Control Of Visual Perception With Phase-Specific Modulation Of Posterior Parietal Cortex, Andrew Jaegle, Tony Ro

Publications and Research

We examined the causal relationship between the phase of alpha oscillations (9–12 Hz) and conscious visual perception using rhythmic TMS (rTMS) while simultaneously recording EEG activity. rTMS of posterior parietal cortex at an alpha frequency (10 Hz), but not occipital or sham rTMS, both entrained the phase of subsequent alpha oscillatory activity and produced a phase-dependent change on subsequent visual perception, with lower discrimination accuracy for targets presented at one phase of the alpha oscillatory waveform than for targets presented at the opposite phase. By extrinsically manipulating the phase of alpha before stimulus presentation, we provide direct evidence that the …

Network Dynamics Of Visual Naming, Christopher R. Conner

Dissertations and Theses (Open Access)

Recognition and naming of objects and actions are fundamental components of language. They involve several different systems working in coordination to accomplish a complex behavior. During visual naming, sensory and semantic processing are carried out by dedicated cortical substrates in the temporal and occipital lobes, while response selection and articulatory planning are handled by prefrontal cortex. Despite decades of research using lesion analysis, functional MRI and electro-encephalography, the precise dynamics involved remain unknown due to the inadequate spatio-temporal resolution of these methodologies. Of particular interest is the organization of semantic knowledge and the degree of serial and parallel organization of …

Cosmetic Neurology: Enhancement Of The Mind And Attention Deficit Hyperactive Disorder Medication Abuse Among College Students, Mary M. Huff

Senior Honors Theses

Cosmetic neurology is becoming increasingly popular, and it is not just sleep deprived, over worked college students who are interested. People are beginning to seek off-label prescriptions for medications that are typically used to treat disorders such as attention deficit hyperactive disorder (ADHD) or narcolepsy, while researchers are trying to create drugs used solely for mind enhancement purposes. Along with these drugs come many legal and ethical quandaries relating to the regulation of current use as well as the what ifs of future possibilities. A survey was conducted among college students regarding the diagnosis of ADHD, the abuse of ADHD …

Empathy-Based Conservation: An Interdisciplinary Approach To Conservation Policy And Decision-Making, Kaitlyn Delashmutt

Department of Environmental Studies: Undergraduate Student Theses

In the late 20^th century, neuroscientists in Italy discovered a neuron in the brain capable of mentally mimicking the emotions derived from the actions of others (Rizzolatti and Craighero, 2004). It is the process that makes your elbow ache when someone else knocks their elbow on the counter or the uncontrollable smile that creeps up when someone smiles at you. No questions asked, people intuitively sense what others are feeling. The old school of thought was that humans deduced through logic and reason the actions of others and interpreted the emotions through a rational process (Carew et al, 2008). …

To See Or Not To See: Prestimulus Α Phase Predicts Visual Awareness, Kyle E. Mathewson, Gabriele Gratton, Monica Fabiani, Diane M. Beck, Tony Ro

Publications and Research

We often fail to see something that at other times is readily detectable. Because the visual stimulus itself is unchanged, this variability in conscious awareness is likely related to changes in the brain. Here we show that the phase of EEG α rhythm measured over posterior brain regions can reliably predict both subsequent visual detection and stimulus-elicited cortical activation levels in a metacontrast masking paradigm. When a visual target presentation coincides with the trough of an α wave, cortical activation is suppressed as early as 100 ms after stimulus onset, and observers are less likely to detect the target. Thus, …

Neural Substrates Of Sound–Touch Synesthesia After A Thalamic Lesion, Michael S. Beauchamp, Tony Ro

Publications and Research

Neural plasticity induced by stroke can mediate positive outcomes, such as recovery of function, but can also result in the formation of abnormal connections with negative consequences for perception and cognition. In three experiments using blood-oxygen level dependent (BOLD) functional magnetic resonance imaging, we examined the neural substrates of acquired auditory-tactile synesthesia, in which certain sounds can produce an intense somatosensory tingling sensation in a patient with a thalamic lesion. Compared with nine normal controls, the first experiment showed that the patient had a threefold greater BOLD response to sounds in the parietal operculum, the location of secondary somatosensory cortex. …

Human Mst But Not Mt Responds To Tactile Stimulation, Michael S. Beauchamp, Nafi E. Yasar, Neel Kishan, Tony Ro

Publications and Research

Previous reports of tactile responses in human visual area MT/V5 have used complex stimuli, such as a brush stroking the arm. These complex moving stimuli are likely to induce imagery of visual motion, which is known to be a powerful activator of MT. The area described as “MT” in previous reports consists of at least two distinct cortical areas, MT and MST. Using functional magnetic resonance imaging, we separately localized human MT and MST and measured their response to vibrotactile stimuli unlikely to induce imagery of visual motion. Strong vibrotactile responses were observed in MST but not in MT. Vibrotactile …

Visual Enhancing Of Tactile Perception In The Posterior Parietal Cortex, Tony Ro, Ruth Wallace, Judith Hagedorn, Alessandro Farnè, Elizabeth Pienkos

Publications and Research

The visual modality typically dominates over our other senses. Here we show that after inducing an extreme conflict in the left hand between vision of touch (present) and the feeling of touch (absent), sensitivity to touch increases for several minutes after the conflict. Transcranial magnetic stimulation of the posterior parietal cortex after this conflict not only eliminated the enduring visual enhancement of touch, but also impaired normal tactile perception. This latter finding demonstrates a direct role of the parietal lobe in modulating tactile perception as a result of the conflict between these senses. These results provide evidence for visual-to-tactile perceptual …

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 …

Transcranial Magnetic Stimulation Of The Prefrontal Cortex Delays Contralateral Endogenous Saccades, Tony Ro, Avishai Henik, Liana Machado, Robert D. Rafal

Publications and Research

The contributions of the superior prefrontal cortex (SPFC) and the superior parietal lobule (SPL) in generating voluntary endogenous and reflexive visually guided saccades were investigated using transcranial magnetic stimulation (TMS). Subjects made choice saccades to the left or right visual field in response to a central arrowhead (endogenous go signal) or a peripheral asterisk (exogenous go signal) that were presented along with a single TMS pulse at varying temporal intervals. TMS over the SPFC increased latencies for saccades made in response to an endogenous go signal toward the contralateral hemifield. No effects were observed when the go signal was exogenous …