Life Sciences Commons^™

The Principled Control Of False Positives In Neuroimaging, Craig M. Bennett, George L. Wolford, Michael B. Miller

Dartmouth Scholarship

An incredible amount of data is generated in the course of a functional neuroimaging experiment. The quantity of data gives us improved temporal and spatial resolution with which to evaluate our results. It also creates a staggering multiple testing problem. A number of methods have been created that address the multiple testing problem in neuroimaging in a principled fashion. These methods place limits on either the familywise error rate (FWER) or the false discovery rate (FDR) of the results. These principled approaches are well established in the literature and are known to properly limit the amount of false positives across …

Damage To Association Fiber Tracts Impairs Recognition Of The Facial Expression Of Emotion, Carissa Philippi, Shruti Mehta, Thomas Grabowski, Ralph Adolphs, David Rudrauf

Psychology Faculty Works

No abstract provided.

A Functional Role For The Ventrolateral Prefrontal Cortex In Non-Spatial Auditory Cognition, Y. E. Cohen, B. E. Russ, S. J. Davis, A. E. Baker, A. L. Ackelson, R. Niteck

Dartmouth Scholarship

Spatial and non-spatial sensory information is hypothesized to be evaluated in parallel pathways. In this study, we tested the spatial and non-spatial sensitivity of auditory neurons in the ventrolateral prefrontal cortex (vPFC), a cortical area in the non-spatial pathway. Activity was tested while non-human primates reported changes in an auditory stimulus' spatial or non-spatial features. We found that vPFC neurons were reliably modulated during a non-spatial auditory task but were not modulated during a spatial auditory task. The degree of modulation during the non-spatial task correlated positively with the monkeys' behavioral performance. These results are consistent with the hypotheses that …

Aging Influences The Neural Correlates Of Lexical Decision But Not Automatic Semantic Priming, Brian T. Gold, Anders H. Andersen, Greg A. Jicha, Charles D. Smith

Neuroscience Faculty Publications

Human behavioral data indicate that older adults are slower to perform lexical decisions (LDs) than young adults but show similar reaction time gains when these decisions are primed semantically. The present study explored the functional neuroanatomic bases of these frequently observed behavioral findings. Young and older groups completed unprimed and primed LD tasks while functional magnetic resonance imaging (fMRI) was recorded, using a fully randomized trial design paralleling those used in behavioral research. Results from the unprimed task found that age-related slowing of LD was associated with decreased activation in perceptual extrastriate regions and increased activation in regions associated with …

Manipulating Neuronal Circuits With Endogenous And Recombinant Cell-Surface Tethered Modulators, Mande Holford, Sebastian Auer, Martin Laqua, Ines Ibanez-Tallon

Publications and Research

Neuronal circuits depend on the precise regulation of cell-surface receptors and ion channels. An ongoing challenge in neuroscience research is deciphering the functional contribution of specifi c receptors and ion channels using engineered modulators. A novel strategy, termed “tethered toxins”, was recently developed to characterize neuronal circuits using the evolutionary derived selectivity of venom peptide toxins and endogenous peptide ligands, such as lynx1 prototoxins. Herein, the discovery and engineering of cell-surface tethered peptides is reviewed, with particular attention given to their cell-autonomy, modular composition, and genetic targeting in different model organisms. The relative ease with which tethered peptides can be …

Higher Education And The Society For Neuroscience: A Website Proposal That Helped Catalyze A Change In Policy, Richard F. Olivo

Neuroscience: Faculty Publications

In the spring of 2007, the Society for Neuroscience (SfN) did not include support for higher education as a priority in its strategic plan. By the spring of 2009, its priorities had changed. One catalyst for that change was a proposal for a website that would list, review, and rate resources for teaching neuroscience at the graduate and undergraduate level. The proposal was sent to and accepted by SfN Council in August 2008; by spring 2009, SfN had taken initial steps to implement it. Two documents are presented here that mark the change in policy: the website proposal, and SfN …

The Epigenetics Of Sex Differences In The Brain, Margaret M. Mccarthy, Anthony P. Auger, Tracy L. Bale, Geert De Vries, Gregory A. Dunn, Nancy Forger, Elaine K. Murray, Bridget M. Nugent, Jaclyn M. Schwarz, Melinda E. Wilson

Neuroscience Institute Faculty Publications

Epigenetic changes in the nervous system are emerging as a critical component of enduring effects induced by early life experience, hormonal exposure, trauma and injury, or learning and memory. Sex differences in the brain are largely determined by steroid hormone exposure during a perinatal sensitive period that alters subsequent hormonal and nonhormonal responses throughout the lifespan. Steroid receptors are members of a nuclear receptor transcription factor superfamily and recruit multiple proteins that possess enzymatic activity relevant to epigenetic changes such as acetylation and methylation. Thus steroid hormones are uniquely poised to exert epigenetic effects on the developing nervous system to …

Farm Focus - Fall 2009, Brian K. Whitlock, Matt Welborn, Maria Prado, Amy Plummer

Faculty Publications and Other Works -- Large Animal Clinical Sciences

No abstract provided.

Neonatal Injury Alters Adult Pain Sensitivity By Increasing Opioid Tone In The Periaqueductal Gray, Jamie L. Laprairie, Anne Z. Murphy Phd

Neuroscience Institute Faculty Publications

Studies in both rodents and humans have shown that acute inflammatory pain experienced during the perinatal period produces long-term decreases in pain sensitivity (hypoalgesia) (Grunau et al., 1994a , 2001 ; Ren et al., 2004 ; LaPrairie and Murphy, 2007 ). To date, the mechanisms underlying these long-term adaptations, however, have yet to be elucidated. The present studies tested the hypothesis that neonatal inflammatory pain induces an upregulation in endogenous opioid tone that is maintained into adulthood, and that this increase in opioid tone provides the underlying mechanism for the observed hypoalgesia. On the day of birth (P0), inflammatory pain …

Impairments In Attention In Occasionally Snoring Children: An Event-Related Potential Study., Maria E. Barnes, Elizabeth A. Huss, Krista N. Garrod, Eric Van Ray, Ehab Dayyat, David Gozal, Dennis L. Molfese

Faculty Scholarship

Objective: To determine whether minimal snoring is benign in children. Procedure: 22 rarely snoring children (mean age = 6.9 years, 11 females) and age- and sex-matched controls participated in an auditory oddball task wearing 128-electrode nets. Parents completed the Conners Parent Rating Scales–Revised Long (CPRS–R:L). Results: Snorers scored significantly higher on four CPRS-R:L subscales. Stepwise regression indicated that two ERP variables from a region of the ERP that peaked at 844 msec post-stimulus onset predicted CPRS-R:L Attention Deficit Hyperactivity Disorder (ADHD) Index scores. Conclusions: Occasional snorers, according to parental report, do exhibit ADHD-like behaviors. Basic sensory processing is longer than …

Sleep-Disordered Breathing Affects Auditory Processing In 5–7 Year-Old Children: Evidence From Brain Recordings, Alexandra P.F. Key, Dennis L. Molfese, Louise O’Brien, David Gozal

Center for Brain, Biology, and Behavior: Faculty and Staff Publications

Poor sleep in children is associated with lower neurocognitive functioning and increased maladaptive behaviors. The current study examined the impact of snoring (the most common manifestation of sleep-disordered breathing) on cognitive and brain functioning in a sample of 35 asymptomatic children ages 5–7 years identified in the community as having habitual snoring (SDB). All participants completed polysomnographic, neurocognitive (NEPSY) and psychophysiological (ERPs to speech sounds) assessments. The results indicated that sub-clinical levels of SDB may not necessarily lead to reduced performance on standardized behavioral measures of attention and memory. However, brain indices of speech perception and discrimination (N1/P2) are sensitive …

P2x Antagonists Inhibit Styryl Dye Entry Into Hair Cells, M. A. Crumling, M. Tong, K. L. Aschenbach, L. Liu

University Faculty Publications and Creative Works

The styryl pyridinium dyes, FM1-43 and AM1-43, are fluorescent molecules that can permeate the mechanotransduction channels of hair cells, the sensory receptors of the inner ear. When these dyes are applied to hair cells, they enter the cytoplasm rapidly, resulting in a readily detectable intracellular fluorescence that is often used as a molecular indication of mechanotransduction channel activity. However, such dyes can also permeate the ATP receptor, P2X2. Therefore, we explored the contribution of P2X receptors to the loading of hair cells with AM1-43. The chick inner ear was found to express P2X receptors and to release ATP, similar to …

P2x Antagonists Inhibit Styryl Dye Entry Into Hair Cells, M. A. Crumling, M. Tong, K. L. Aschenbach, L. Liu

University Faculty Publications and Creative Works

The styryl pyridinium dyes, FM1-43 and AM1-43, are fluorescent molecules that can permeate the mechanotransduction channels of hair cells, the sensory receptors of the inner ear. When these dyes are applied to hair cells, they enter the cytoplasm rapidly, resulting in a readily detectable intracellular fluorescence that is often used as a molecular indication of mechanotransduction channel activity. However, such dyes can also permeate the ATP receptor, P2X2. Therefore, we explored the contribution of P2X receptors to the loading of hair cells with AM1-43. The chick inner ear was found to express P2X receptors and to release ATP, similar to …

Developmental Emergence Of Power-Law Wake Behavior Depends Upon The Functional Integrity Of The Locus Coeruleus, Andrew J. Gall, Badal Joshi, Janet Best, Virginia R. Florang, Jonathan A. Doorn, Mark S. Blumberg

Faculty Publications

STUDY OBJECTIVES:

Daily amounts of sleep and wakefulness are accumulated in discrete bouts that exhibit distinct statistical properties. In adult mammals, sleep bout durations follow an exponential distribution whereas wake bout durations follow a power-law distribution. In infant Norway rats, however, wake bouts initially follow an exponential distribution and only transition to a power-law distribution beginning around postnatal day 15 (P15). Here we test the hypothesis that the locus coeruleus (LC), one of several wake-active nuclei in the brainstem, contributes to this developmental transition.

DESIGN:

At P7, rats were injected subcutaneously with saline or DSP-4, a neurotoxin that targets noradrenergic …

Head And Neck Embryology: An Overview Of Development, Growth And Defect In The Human Fetus, Allison Baylis

Honors Scholar Theses

The purpose of this research is to explore the growth and formation of the head and neck from embryological development through puberty in order to understand how this knowledge is necessary for the development of dental and medical treatments and procedures. This is a necessary aspect of the medical and dental school curriculum at the University of Connecticut Health Center Schools of Medicine and Dental Medicine that needs to be incorporated into the current study of embryology for first-year students. Working with Dr. Christine Niekrash, D.M.D, this paper will cover the embryology and growth of the head, face and oral …

Effects Of Estrogen On Muscle Damage In Response To An Acute Resistance Exercise Protocol, Megan R. Wolf

Honors Scholar Theses

Creatine Kinase (CK) is used as a measure of exercise-induced muscle membrane damage. During acute eccentric (muscle lengthening) exercise, muscle sarcolemma, sarcoplasmic reticulum, and Z-lines are damaged, thus causing muscle proteins and enzymes to leak into the interstitial fluid.

Strenuous eccentric exercise produces an elevation of oxygen free radicals, which further increases muscle damage. Muscle soreness and fatigue can be attributed to this membrane damage. Estradiol, however, may preserve membrane stability post-exercise (Brancaccio, Maffulli, & Limongelli, 2007; Carter, Dobridge, & Hackney, 2001; Tiidus, 2001). Because estradiol has a similar structure to Vitamin E, which is known to have antioxidant properties, …

Salivary Cortisol, Psychological Stress And Depressive Symptoms Among Patients Undergoing Colon Cancer Screenings, Allyson Reid

Honors Scholar Theses

As the second leading cause of cancer-related deaths in the United States, colon cancer has a high cure rate if detected early by a colonoscopy (U.S.

Cancer Statistics Working Group, 2007). However, more than 41 million at-risk Americans are not properly receiving colonoscopy screenings according to the recommendations of the Center for Disease Control. This study provides insight into the physiological and psychological benefits of the colonoscopy procedure over and above cancer detection and prevention. Thirty-six patients receiving colonoscopic screening at the University of Connecticut Health Center participated in this study. A questionnaire battery that assessed perceived stress, depressive symptoms, …

Differentiation Of Human Embryonic Stem Cell (Hesc) Derived Pyramidal Neurons, Eagan Jacqueline

Honors Scholar Theses

The mammalian cerebral neocortex is a complex six-layered structure containing multiple types of neurons. Pyramidal neurons of the neocortex are formed during development in an inside-out manner, by which deep layer (DL) neurons are generated first, and upper layer (UL) neurons are generated last. Neurons within the six-layered neocortex express unique markers for their position, showing whether they are subplate, deep layer, upper layer, or Cajal-Retzius neurons. The sequential generation of cortical layers, which exists in vivo, has been partially recapitulated in vitro by differentiation of mouse embryonic stem cells (Gaspard et al., 2008) and human embryonic stem cells (hESC) …

Intrinsic Ph-Sensitivity Of Cells In The Retrotrapezoid Nucleus: Possible Role Of Glia In Respiratory Drive, Nicole Edwards

Honors Scholar Theses

An increase in carbon dioxide (CO2) and protons (H+) are the primary signals for breathing. Cells that sense changes in CO2/H+ levels and increase breathing accordingly are located in a region of the caudal medulla oblongata called the retrotrapezoid nucleus (RTN). Specifically, select RTN neurons are intrinsically pH sensitive and send excitatory projections to the respiratory rhythm generator to drive breathing. Glial cells in the RTN are thought to contribute to this respiratory drive, possibly by releasing ATP in response to increases in CO2/H+ levels.

However, pH sensitivity of RTN glial cells has yet to be determined.

Therefore, the goal …

The Role Of Epha4 In Glial Scar Formation Following Injury, Krysti Todd

Honors Scholar Theses

Although many areas of the brain lose their regenerative capacity with age, stem cell niches have been identified in both the subventricular zone (SVZ) along the lateral walls of the lateral ventricles and the subgranular zone (SGZ) of the dentate gyrus (Gage, 2000; Alvarez-Buylla et al., 2001; Alvarez-Buylla and Lim, 2004). The SVZ niche utilizes many mechanisms to determine the migration patterns of neuroblasts along the RMS into the olfactory bulb, one being Eph/ephrin signaling (Conover et al., 2000; Holmberg et al., 2005). EphA4-mediated signaling is necessary for axon guidance during development, and its continued expression in the SVZ niche …

Striatal Neuroinflammation Promotes Parkinsonism In Rats, Dong-Young Choi, Mei Liu, Randy L. Hunter, Wayne A. Cass, Jignesh D. Pandya, Patrick G. Sullivan, Eun-Joo Shin, Hyoung-Chun Kim, Don M. Gash, Guoying Bing

Neuroscience Faculty Publications

BACKGROUND: Sporadic Parkinson's disease (PD) is a progressive neurodegenerative disorder with unknown cause, but it has been suggested that neuroinflammation may play a role in pathogenesis of the disease. Neuroinflammatory component in process of PD neurodegeneration was proposed by postmortem, epidemiological and animal model studies. However, it remains unclear how neuroinflammatory factors contribute to dopaminergic neuronal death in PD.

FINDINGS: In this study, we analyzed the relationship among inducible nitric oxide synthase (iNOS)-derived NO, mitochondrial dysfunction and dopaminergic neurodegeneration to examine the possibility that microglial neuroinflammation may induce dopaminergic neuronal loss in the substantia nigra. Unilateral injection of lipopolysaccharide (LPS) …

Same-Sex Social Behavior In Meadow Voles: Multiple And Rapid Formation Of Attachments, Annaliese K. Beery, David M. Routman, Irving Zucker

Neuroscience: Faculty Publications

Adult meadow voles (Microtus pennsylvanicus) are solitary in the spring–summer reproductive season, but during winter months, females and males are socially tolerant and aggregate in groups. This behavioral difference is triggered by day length: female meadow voles housed in short, winterlike day lengths form same-sex partner preferences, whereas those housed in long, summer-like day lengths are less social. The present study demonstrates that same-sex social attachments in short day lengths are not exclusive; females formed concurrent attachments with more than one individual, and with non-kin as well as siblings. Partner preferences between females were established within one day of cohousing …

Microsaccade Rate Varies With Subjective Visibility During Motion-Induced Blindness, Po-Jang Hsieh, Peter U. Tse

Dartmouth Scholarship

Motion-induced blindness (MIB) occurs when a dot embedded in a motion field subjectively vanishes. Here we report the first psychophysical data concerning effects of microsaccade/eyeblink rate upon perceptual switches during MIB. We find that the rate of microsaccades/eyeblink rises before and after perceptual transitions from not seeing to seeing the dot, and decreases before perceptual transitions from seeing it to not seeing it. In addition, event-related fMRI data reveal that, when a dot subjectively reappears during MIB, the blood oxygen-level dependent (BOLD) signal increases in V1v and V2v and decreases in contralateral hMT+. These BOLD signal changes observed upon perceptual …

Frequency And Spatial Characteristics Of Highfrequency Neuromagnetic Signals In Childhood Epilepsy, Jing Xiang, Yang Liu, Yingying Wang, Elijah G. Kirtman, Cincinnati Children’S Hospital Medical Center Kotecha, Yangmei Chen, Xiaolin Huo, Hisako Fujiwara, Nat Hemasilpin, Ki Lee, Francesco T. Mangano, James Leach, Blaise Jones, Ton Degrauw, Douglas Rose

Center for Brain, Biology, and Behavior: Faculty and Staff Publications

Purpose. Invasive intracranial recordings have suggested that high-frequency oscillation is involved in epileptogenesis and is highly localized to epileptogenic zones. The aim of the present study is to characterize the frequency and spatial patterns of high-frequency brain signals in childhood epilepsy using a non-invasive technology. Methods. Thirty children with clinically diagnosed epilepsy were studied using a whole head magnetoencephalography (MEG) system. MEG data were digitized at 4 000 Hz. The frequency and spatial characteristics of high-frequency neuromagnetic signals were analyzed using continuous wavelet transform and beamformer. Threedimensional magnetic resonance imaging (MRI) was obtained for each patient to localize magnetic sources. …

Revisiting The Mind- Body Paradox: Can Brain Functioning Explain Moral Reasoning?, Brianna Mahan

Honors Projects in Science and Technology

With this paper, I attempt to explore possible neural correlates of morality. We define morality as the one part, structure, or process of the brain that could be linked to an innate ability to understand and determine right versus wrong. An understanding of right of right and wrong can provide us with a sense of guilt and empathy for an action or another person. Right and wrong will be defined through a primarily Judeo-Christian perspective, as it was the principle respondent among our questionnaire. There is a possibility for differences among other religions. For that reason, we expect the neural …

Fruitless, Doublesex And The Genetics Of Social Behavior In Drosophila Melanogaster, Kathleen King Siwicki, E. A. Kravitz

Biology Faculty Works

Two genes coding for transcription factors, fruitless and doublesex, have been suggested to play important roles in the regulation of sexually dimorphic patterns of social behavior in Drosophila melanogaster. The generalization that fruitless specified the development of the nervous system and doublesex specified non-neural tissues culminated with claims that fruitless was both necessary and sufficient to establish sex-specific patterns of behavior. Several recent articles refute this notion, however, demonstrating that at a minimum, both fruitless and doublesex are involved in establishing sexually dimorphic features of neural circuitry and behavior in fruit flies.

Farm Focus - Spring 2009, Brian K. Whitlock, Matt Welborn, Maria Prado, Amy Plummer

Faculty Publications and Other Works -- Large Animal Clinical Sciences

No abstract provided.

Criterial Noise Effects On Rule-Based Category Learning: The Impact Of Delayed Feedback, Shawn W. Ell, David A. Ing, Todd W. Maddox

Psychology Faculty Scholarship

Variability in the representation of the decision criterion is assumed in many category learning models yet few studies have directly examined its impact. On each trial, criterial noise should result in drift in the criterion and will negatively impact categorization accuracy, particularly in rule-based categorization tasks where learning depends upon the maintenance and manipulation of decision criteria. The results of three experiments test this hypothesis and examine the impact of working memory on slowing the drift rate. Experiment 1 examined the effect of drift by inserting a 5 s delay between the categorization response and the delivery of corrective feedback, …

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, …

The Sleeping Brain's Influence On Verbal Memory: Boosting Resistance To Interference, Jeffrey M. Ellenbogen, Justin C. Hulbert, Ying Jiang, Robert Stickgold

Dartmouth Scholarship

Memories evolve. After learning something new, the brain initiates a complex set of post-learning processing that facilitates recall (i.e., consolidation). Evidence points to sleep as one of the determinants of that change. But whenever a behavioral study of episodic memory shows a benefit of sleep, critics assert that sleep only leads to a temporary shelter from the damaging effects of interference that would otherwise accrue during wakefulness. To evaluate the potentially active role of sleep for verbal memory, we compared memory recall after sleep, with and without interference before testing. We demonstrated that recall performance for verbal memory was greater …