Neuroscience and Neurobiology Commons^™

Flexibly Adapting To Emotional Cues: Examining The Functional And Structural Correlates Of Emotional Reactivity And Emotion Control In Healthy And Depressed Individuals, Steven G. Greening

Electronic Thesis and Dissertation Repository

The ability of emotionally significant stimuli to bias our behaviour is an evolutionarily adaptive phenomenon. However, sometimes emotions become excessive, inappropriate, and even pathological, like in major depressive disorder (MDD). Emotional flexibility includes both the neural processes involved in reacting to, or representing, emotional significance, and those involved in controlling emotional reactivity. MDD represents a potentially distinct form of emotion (in)flexibility, and therefore offers a unique perspective for understanding both the integration of conflicting emotional cues and the neural regions involved in actively controlling emotional systems.

The present investigation of emotional flexibility began by considering the functional neural correlates of …

Prioritized Detection Of Personally Familiar Faces, Maria Ida Gobbini, Jason D. Gors, Yaroslav O. Halchenko, Courtney Rogers, J Swaroop Guntupalli, Howard C. Hughes, Carlo Cipolli

Dartmouth Scholarship

We investigated whether personally familiar faces are preferentially processed in conditions of reduced attentional resources and in the absence of conscious awareness. In the first experiment, we used Rapid Serial Visual Presentation (RSVP) to test the susceptibility of familiar faces and faces of strangers to the attentional blink. In the second experiment, we used continuous flash interocular suppression to render stimuli invisible and measured face detection time for personally familiar faces as compared to faces of strangers. In both experiments we found an advantage for detection of personally familiar faces as compared to faces of strangers. Our data suggest that …

Lesions Of The Intergeniculate Leaflet Lead To A Reorganization In Circadian Regulation And A Reversal In Masking Responses To Photic Stimuli In The Nile Grass Rat, Andrew J. Gall, Laura Smale, Lily Yan, Antonio A. Nunez

Faculty Publications

Light influences the daily patterning of behavior by entraining circadian rhythms and through its acute effects on activity levels (masking). Mechanisms of entrainment are quite similar across species, but masking can be very different. Specifically, in diurnal species, light generally increases locomotor activity (positive masking), and in nocturnal ones, it generally suppresses it (negative masking). The intergeniculate leaflet (IGL), a subdivision of the lateral geniculate complex, receives direct retinal input and is reciprocally connected with the primary circadian clock, the suprachiasmatic nucleus (SCN). Here, we evaluated the influence of the IGL on masking and the circadian system in a diurnal …

Neural Activations During Visual Sequence Learning Leave A Trace In Post-Training Spontaneous Eeg, Clara Moisello, Hadj Boumediene Meziane, Simon Kelly, Bernardo Perfetti, Svetlana Kvint, Nicholas Voutsinas, Daniella Blanco, Angelo Quartarone, Giulio Tononi, Maria Felice Ghilardi

Publications and Research

Recent EEG studies have shown that implicit learning involving specific cortical circuits results in an enduring local trace manifested as local changes in spectral power. Here we used a well characterized visual sequence learning task and high density-(hd-)EEG recording to determine whether also declarative learning leaves a post-task, local change in the resting state oscillatory activity in the areas involved in the learning process. Thus, we recorded hd-EEG in normal subjects before, during and after the acquisition of the order of a fixed spatial target sequence (VSEQ) and during the presentation of targets in random order (VRAN). We first determined …

Amyloid Beta Resistance And The Warburg Effect: Re-Examining Alzheimer's Disease, Jordan Taylor Newington

Electronic Thesis and Dissertation Repository

Alzheimer’s disease (AD) is characterized by deposition of the amyloid beta (Ab) peptide in the brain, an event which frequently but not universally correlates with nerve cell death. Although most nerve cells die in response to Ab, small populations of cells are able to survive by becoming resistant to Ab toxicity. Understanding the mechanisms by which cells become resistant to Ab may reveal novel treatments for AD. Interestingly, nerve cell lines selected for resistance against Ab exhibit increased glucose uptake and glycolytic flux. Here I show that these metabolic changes are mediated through an upregulation of pyruvate dehydrogenase kinase 1 …

Targeted Training Of The Decision Rule Benefits Rule-Guided Behavior In Parkinson’S Disease, Shawn W. Ell

Psychology Faculty Scholarship

The impact of Parkinson’s disease (PD) on rule-guided behavior has received considerable attention in cognitive neuroscience. The majority of research has used PD as a model of dysfunction in fronto-striatal networks, but very few attempts have been made to investigate the possibility of adapting common experimental techniques in an effort to identify the conditions that are most likely to facilitate successful performance. The present study investigated a targeted training paradigm designed to facilitate rule learning and application using rule-based categorization as a model task. Participants received targeted training in which there was no selective-attention demand (i.e., stimuli varied along a …

Dynamics Of The Fitzhugh-Nagumo Neuron Model, Zechariah Thurman

Physics

In this paper, the dynamical behavior of the Fitzhugh-Nagumo model is examined. The relationship between neuron input current and the firing frequency of the neuron is characterized. Various coupling schemes are also examined, and their effects on the dynamics of the system is discussed. The phenomenon of stochastic resonance is studied for a single uncoupled Fitzhugh-Nagumo neuron.

Cognitive Effects Of Combined Physical And Mental Exercise: Interactive Vs. Synchronous, Caitlin Moore

Honors Theses

Many high quality randomized clinical trials have now clarified the strong relationship between exercise and cognition (Colcombe & Kramer, 2003). A growing area of exercise research has been focused on the effects of “exergaming” on cognitive function. Exergaming provides an individual with the ability to physically interact with a virtual environment (O’Leary et al., 2011). Recent research has shown an added cognitive benefit of interactive mental and physical exercise, when using a virtual reality-enhanced stationary bike. It is unclear whether interactivity is required, or if added cognitive benefit is "simply" from doing two things at the same time and reaping …

Comparison Of Wild And Cultivated Extracts Of Cordyceps Sinensis Apoptotic Potential, Katelyn Staring

Honors Theses

Cordyceps sinensis is a mushroom which contains the compound cordycepin (3’-deoxyadenosine), an analogue of adenosine. In Traditional Chinese Medicine (TCM), cordycepin has multipurpose pharmacological uses including purported anti-tumor effects. In the present study, cordycepin was extracted from the wild mushroom as well as from various commercially available cultivated extracts. Previous research in this lab has demonstrated that cultivated extracts contain less cordycepin than the wild mushroom. However, it is unclear if the decrease in cordycepin correlates with decreased activity. To measure anti-tumor activity, extracts were used to treat human breast cancer cells (MCF-7 cells). In other labs, cordycepin has been …

Expression Of The Chemokine Receptor, Cxcr4, And Its Ligand, Sdf-1, Are Increased In Purkinje Cells Of The Multiple System Atrophy Cerebellum, Megan Welter

Masters Theses

Multiple System Atrophy (MSA) is a sporadic, neurodegenerative disease that consists of three conditions: autonomic dysfunction, Parkinsonism and cerebellar ataxia. Our lab conducted an Affymetrix global gene expression analysis using pons tissue of MSA patients to determine genes that are differentially expressed when compared to non- MSA controls. This study identified upregulated genes, including the C-X-C chemokine receptor type 4, CXCR4, to which stromal cell-derived factor-I (SDF-1) is the natural ligand. The CXCR4/SDF-1 signaling pair has been sho.wn to play multiple roles in the brain, such as inducing neuronal apoptosis and promoting leukocyte recruitment during inflammation. The MSA cerebellum presents …

A Mechanistic Hypothesis Of The Factors That Enhance Vulnerability To Nicotine Use In Females, Laura O'Dell

Laura Elena O'Dell

Women are particularly more vulnerable to tobacco use than men. This review proposes a unifying hypothesis that females experience greater rewarding effects of nicotine and more intense stress produced by withdrawal than males. We also provide a neural framework whereby estrogen promotes greater rewarding effects of nicotine in females via enhanced dopamine release in the nucleus accumbens (NAcc). During withdrawal, we suggest that corticotropin-releasing factor (CRF) stress systems are sensitized and promote a greater suppression of dopamine release in the NAcc of females versus males. Taken together, females display enhanced nicotine reward via estrogen and amplified effects of withdrawal via …

Dominance Of Orientation Over Frequency In The Perception Of 3-D Slant And Shape, Danny M. Tam, Ji Shin, Andrea Li

Publications and Research

In images of textured three-dimensional surfaces, pattern changes can be characterized as changes in orientation and spatial frequency, features for which neurons in primary visual cortex are classically selective. Previously, we have demonstrated that correct 3-D shape perception is contingent on the visibility of orientation flows that run parallel to the surface curvature. We sought to determine the relative contributions of orientation modulations (OMs) and frequency modulations (FMs) for the detection of slant and shape from 3-D surfaces. Results show that 1) when OM and FM indicate inconsistent degrees of surface slant or curvature, observer responses were consistent with the …

The Development Of Electroconvulsive Therapy, Deborah J. Sevigny-Resetco

Sound Neuroscience: An Undergraduate Neuroscience Journal

The current acceptance of electroconvulsive therapy (ECT) as a suitable treatment for depression is a result of years of medical and ethical controversy. The treatment faced social, political, and scientific barriers as it developed; however, its effectiveness in treating mental disorders has allowed it to remain in use to this day. This paper will trace the changes electroconvulsive therapy has seen in technology, application, and societal endorsement over the years.

Genetics In Non-Genetic Model Systems, Carlos Lois, James Groves

Carlos Lois

The past few decades have seen the field of genetic engineering evolve at a rapid pace, with neuroscientists now equipped with a wide range of tools for the manipulation of an animal's genome in order to study brain function. However, the number of species to which these technologies have been applied, namely the fruit fly, C. elegans, zebrafish and mouse, remains relatively few. This review will discuss the variety of approaches to genetic modification that have been developed in such traditional 'genetic systems', and highlight the progress that has been made to translate these technologies to alternative species such as …

Wandering Neuronal Migration In The Postnatal Vertebrate Forebrain, Benjamin Scott, Timothy Gardner, Ni Ji, Michale Fee, Carlos Lois

Carlos Lois

Most non-mammalian vertebrate species add new neurons to existing brain circuits throughout life, a process thought to be essential for tissue maintenance, repair, and learning. How these new neurons migrate through the mature brain and which cues trigger their integration within a functioning circuit is not known. To address these questions, we used two-photon microscopy to image the addition of genetically labeled newly generated neurons into the brain of juvenile zebra finches. Time-lapse in vivo imaging revealed that the majority of migratory new neurons exhibited a multipolar morphology and moved in a nonlinear manner for hundreds of micrometers. Young neurons …

Genetic Labeling Of Neuronal Subsets Through Enhancer Trapping In Mice, Wolfgang Kelsch, Alberto Stolfi, Carlos Lois

Carlos Lois

The ability to label, visualize, and manipulate subsets of neurons is critical for elucidating the structure and function of individual cell types in the brain. Enhancer trapping has proved extremely useful for the genetic manipulation of selective cell types in Drosophila. We have developed an enhancer trap strategy in mammals by generating transgenic mice with lentiviral vectors carrying single-copy enhancer-detector probes encoding either the marker gene lacZ or Cre recombinase. This transgenic strategy allowed us to genetically identify a wide variety of neuronal subpopulations in distinct brain regions. Enhancer detection by lentiviral transgenesis could thus provide a complementary method for …

Similarity Of Visual Selectivity Among Clonally Related Neurons In Visual Cortex, Gen Ohtsuki, Megumi Nishiyama, Takashi Yoshida, Tomonari Murakami, Mark Histed, Carlos Lois, Kenichi Ohki

Carlos Lois

Neurons in rodent visual cortex are organized in a salt-and-pepper fashion for orientation selectivity, but it is still unknown how this functional architecture develops. A recent study reported that the progeny of single cortical progenitor cells are preferentially connected in the postnatal cortex. If these neurons acquire similar selectivity through their connections, a salt-and-pepper organization may be generated, because neurons derived from different progenitors are intermingled in rodents. Here we investigated whether clonally related cells have similar preferred orientation by using a transgenic mouse, which labels all the progeny of single cortical progenitor cells. We found that preferred orientations of …

Increasing Heterogeneity In The Organization Of Synaptic Inputs Of Mature Olfactory Bulb Neurons Generated In Newborn Rats, Wolfgang Kelsch, Shuyin Sim, Carlos Lois

Carlos Lois

New neurons are added into the mammalian olfactory bulb throughout life, but it remains unknown whether the properties of new neurons generated in newborn animals differ from those added during adulthood. We compared the densities of glutamatergic synapses of granule cells (GCs) generated in newborn and adult rats over extended periods of time. We observed that, whereas adult-born GCs maintained stable cell-to-cell variability of synaptic densities soon after they integrated into the circuit, cell-to-cell variability of synaptic densities of neonatal-born GCs increased months after their integration. We also investigated whether the synaptic reorganization induced by sensory deprivation occurred differently in …

Coincident Generation Of Pyramidal Neurons And Protoplasmic Astrocytes In Neocortical Columns, Sanjay Magavi, Drew Friedmann, Garrett Banks, Alberto Stolfi, Carlos Lois

Carlos Lois

Astrocytes, one of the most common cell types in the brain, are essential for processes ranging from neural development through potassium homeostasis to synaptic plasticity. Surprisingly, the developmental origins of astrocytes in the neocortex are still controversial. To investigate the patterns of astrocyte development in the neocortex we examined cortical development in a transgenic mouse in which a random, sparse subset of neural progenitors undergoes CRE/lox recombination, permanently labeling their progeny. We demonstrate that neural progenitors in neocortex generate discrete columnar structures that contain both projection neurons and protoplasmic astrocytes. Ninety-five percent of developmental cortical columns labeled in our system …

Investigating Potential Target Genes Of The Rfx Transcription Factor Daf-19 In Caenorhabditis Elegans, He Zhang

Lawrence University Honors Projects

Neurodegenerative diseases, such as Alzheimer’s disease, are characterized by an age-related decrease in the synaptic activity of the patient’s brain. Previous research suggested that a RFX transcription factor DAF-19 in the nematode Caenorhabditis elegans (C. elegans) may be involved in the maintenance of synaptic protein levels. Particularly, worms that were DAF-19A/B defective showed reduced synaptic activities when compared to their age-matched controls.

This study investigated the role of DAF-19A/B isoforms in the C. elegans nervous system. Three genes, F46G11.3, F57B10.9, and F58E2.3 were selected as potential downstream targets of DAF-19A/B based on their potential neuronal expression. …