Neuroscience and Neurobiology Commons^™

Brainstorm: Head Injuries And The Nfl, Part 4: The Physics Of Head Trauma, John J. Medina Ph.D.

Brainstorm

One fine afternoon in the autumn of 2010, Minnesota Vikings defensive end Ray Edwards executed one of the most dangerous acts you can do in football: He speared another player.

Validation Of Interaction Between The Glyt2 And The Nsf, David Quispe Escudero, Hector Cuevas, Luciana Girotto Gentil, Manuel Miranda

COURI Symposium Abstracts, Summer 2012

The Glycine Transporter 2 (GlyT2) is a presynaptic membrane transporter in charge of re-uptake of glycine from the synaptic cleft back into the presynaptic neuron. GlyT2 is present only in vertebrate neurons and possesses a 200 amino- acid long N-terminal tail of unknown function. We hypothesize that such domain serve as a docking site for a network of presynaptic proteins, such as NSF that plays a pivotal role during vesicle transport. Therefore, our goal in this project is to analyze protein-protein interaction between GlyT2 and NSF. We have used co-immunoprecipitation experiments from rat brainstem with GlyT2 and NSF antibodies as …

Stress- And Sex-Related Differences In The Activation Of Neuronal Subtypes In The Basolateral Amygdala Of The Rat, Alejandra E. Lopez, Christina C. Ruiz, Juan M. Bolanos, Jameel N. Hamdan, Kristin Gosselink

COURI Symposium Abstracts, Summer 2012

Previous studies suggest that stress alters the activational profiles among phenotypically-distinct subpopulations of neurons within the basolateral amygdala (BLA) of the rat. Given the connectivity of this region of the brain to the hippocampus, and the implications of the role of the BLA in modulating long-term potentiation associated with memory and learning, inferences of stress having a negative impact on cognition and memory can be drawn. Observations regarding stress response disparities between males and females in our model prompted the investigation of the role gender plays in cognition under conditions of stress, as well as the responses to stress itself. …

Multivoxel Patterns In Face-Sensitive Temporal Regions Reveal An Encoding Schema Based On Detecting Life In A Face, Christine E. Looser, Jyothi S. Guntupalli, Thalia Wheatley

Dartmouth Scholarship

More than a decade of research has demonstrated that faces evoke prioritized processing in a ‘core face network’ of three brain regions. However, whether these regions prioritize the detection of global facial form (shared by humans and mannequins) or the detection of life in a face has remained unclear. Here, we dissociate form-based and animacy-based encoding of faces by using animate and inanimate faces with human form (humans, mannequins) and dog form (real dogs, toy dogs). We used multivariate pattern analysis of BOLD responses to uncover the representational similarity space for each area in the core face network. Here, we …

Resolving Disulfide Bond Patterns In Snap25b Cysteine-Rich Region Using Lc Mass Spectrometry, Nozomi Ogawa

Theses and Dissertations

A global analysis of the human proteome demonstrates that there are ~5500 tryptic fragments that contain four cysteines in close proximity. Elucidating whether they form disulfide bonds in vivo under different conditions is particularly important because cysteines are known to be a vital cellular redox sensor as well as a catalytic site for important biochemical reactions. However, currently there are no methods that can resolve disulfide patterns in closely-packed cysteine residues from a complex sample. In order to address this problem, we have developed a novel mass-spectrometry-based method to identify the different disulfide bonding patterns possible, using SNAP25B cysteine-rich region …

Rapid Activation Of Hindbrain Neurons Following Glycemic Challenge: Regions And Phenotypes, Sarah D. Chenausky, Teresia A. Carreon, Arshad M. Khan

COURI Symposium Abstracts, Summer 2012

Hindbrain neurons are critical for the coordination of feeding, autonomic, and metabolic responses to changes in circulating fuels, such as sugar and fatty acids. Using protein markers such as the Fos transcription factor, previous work has identified key regions of the hindbrain that may be involved in such coordination. However, in these studies, Fos protein staining of hindbrain neurons was performed hours after the hypo- or hyperglycemic challenge was delivered, making activation responses difficult to interpret in relation to the stimulus given. Moreover, these studies generally have employed immunoperoxidase methods to identify Fos-activated neurons without explicitly identifying the chemical phenotypes …

Inhibitors Of Polyisoprenylated Methylated Protein Methyl Esterase (Pmpmease) Cause Neurodegeneration By Altering Microtubules And Gβγ In Pc12 Cells, Jose A. Rivas Jr., Rebekah M. Bach, Jessica Martinez-Jurado, Jorge A. Siera-Fonseca, Sukla Roychowdhury

COURI Symposium Abstracts, Summer 2012

Neurodegeneration, a progressive loss of nerve cells (neurons), occurs in many neurological disorders including Alzheimer’s disease, Parkinson’s disease, Schizophrenia and drug addiction. Disruption of Microtubules (MTs), a major component of cytoskeleton and aggregation of proteins associated with them is the hallmark of neurodegeneration. Gβγ, an important component of G protein signaling has been shown to induce neurite outgrowth of PC12 cells by interacting with microtubules. The goal of the present study is to understand whether interfering with Gβγ-MT mediated pathway causes neurodegeneration. Because prenylation of γ subunits is important for the interaction of Gβγ with MTs, we used inhibitors (L-23 …

Gβγ-Microtubule Interaction And Neurodegeneration, Jane K. Martinez, Jorge Sierra, Sukla Roychowdhury Ph.D.

COURI Symposium Abstracts, Summer 2012

Aberrant organization of microtubules (MTs) is known to be a feature of neurodegeneration, which occurs in many neurological disorder including Alzheimer’s disease, Parkinson’s disease, neuropsychiatric illness such as schizophrenia, and drug addiction. Previously, Gβγ, an important component of G protein-coupled signaling pathways, has been shown to regulate neurite outgrowth by interacting with MTs. The aim of the present study is to understand the Gβγ regulation of MT assembly and its relation to neurodegeneration, using GRK-ct peptide (consists of the carboxy terminus of G protein-coupled-receptor kinase) which is known to inhibit Gβγ-dependent signaling by binding to and sequestering Gβγ. PC12 cells …

Calcium-Binding Proteins In The Lateral Hypothalamic Area: Spatial Relations To Hypocretin/Orexin And Melanin Concentrating Hormone, Briana E. Pinales, Paola Rojas, Claire E. Wells, Arshad M. Khan

COURI Symposium Abstracts, Summer 2012

Lateral hypothalamic area (LHA) neurons are critical for the coordination of feeding behavior and the autonomic control of peripheral hormone release. Although many studies have employed intracranial stimulation (chemical, electrical, optogenetic) in and around the LHA to stimulate food intake and/or control autonomic activity, the chemical phenotype(s) of the neurons responsible for these physiological functions are unknown. This is due, in part, to a lack of basic information regarding the various chemical phenotypes in the LHA and their spatial relations to one another.

We have extended our initial chemoarchitectural profiling efforts of the LHA to examine the LHA distribution of …

Characterization And Localization Of Glycinergic Neurons From The Mouse Brain Stem, Astrid M. Rodriguez, Alejandra C. Camacho, Manuel Miranda

COURI Symposium Abstracts, Summer 2012

The neurotransmitter glycine functions as the major inhibitory neurotransmitter in the brain stem, cerebellum and spinal cord, where is contained in synaptic vesicles within glycinergic neurons. However the location of cell bodies, neuronal projections and connections are undefined to date. While the presence of glycine, the glycine transporters GlyT1, GlyT2 and the vesicular glycine transporter VIAAT may define a glycinergic neuron, little efforts have been made to investigate these neurons. To better identify and characterize these glycinergic neurons, we prepared primary cultures from the brain stem and the retina, using a transgenic mouse that expresses the green fluorescent protein (GFP) …

The Regulation Of The Glycine Transporter 1 By Phosphorylation, Alejandro A. Acuna, Qi Zhang, Vicente Castrejon, Luciana Girotto Gentil, Manuel Miranda

COURI Symposium Abstracts, Summer 2012

The plasma membrane glycine transporters 1 (GlyT1) is the carrier molecule responsible for the fast removal of the inhibitory neurotransmitter glycine from the synaptic cleft back into the presynaptic terminals of glycinergic neurons by an electrogenic, Na⁺-Cl^- transport couple mechanism maintained by the Na⁺,K⁺-ATPase. GlyTs belong to SLC6 family that includes other neurotransmitter transporters, such as the dopamine, norepinephrine, serotonin, and GABA transporters. In order to determine the role of PKC-dependent phosphorylation on GlyT1, we have analyzed the effect of PKC activation by phorbol ester (PMA) on the activity, post-translational modifications and the …

Loss Of Circuits Promoting Appetite Are Associated With Increases In Circuits Promoting Satiety: Where Is The Plasticity Occurring?, Nicole Dominguez, Ellen M. Walker, Arshad M. Khan*

COURI Symposium Abstracts, Summer 2012

Hindbrain catecholamine (CA) neurons promote feeding, whereas arcuate hypothalamic alpha melanocyte-stimulating hormone (αMSH) neurons promote satiety. A key brain region receiving these CA feeding and αMSH satiety signals is the paraventricular hypothalamus (PVH). We have observed that the αMSH inputs unexpectedly increase if the feeding-promoting CA inputs are lesioned. Here, we asked whether the increased αMSH inputs reflect altered numbers of αMSH neurons in the arcuate hypothalamus after the lesion or represent only local changes at the level of the PVH. Immunofluorescently labeled ARH αMSH neurons from 28 control and lesioned rats were counted as follows: confocal images from left …

Insights Into The Role Of The N-Terminus Of The Neuronal Glycine Transporter 2, Diego A. Escobar-Garcia, Ana Garibay, Miryam Pando, Manuel Miranda

COURI Symposium Abstracts, Summer 2012

Hyperekplexia is distinguished by exaggerated muscle tension, sudden shock and even death in response to touch/acoustic stimuli. Genetic analysis showed that mutations on glycinergic proteins on the presynaptic neurons are responsible for the attacks. Mutations in the Glycine Transporter 2 (GlyT2) have been suggested to be the second major cause of hyperekplexia. The GlyT2 consist of twelve transmembrane domains, a 201 amino acid long N-terminus and a shorter C-terminus, both intracellular. Dysfunction of this transporter prevents the intake of glycine from the synapse back to the presynaptic neuron. Our goal is to better understand the role of N-terminus on protein …

Chronic Ethanol Exposure Causes Disinhibited Behavior In Drosophila, Estrella Padilla, Kyung-An Han

COURI Symposium Abstracts, Summer 2012

Ethanol consumption is frequently associated with disinhibited sexual and locomotor behaviors in humans. Dopamine, a major monoamine found in vertebrates and invertebrates, is implicated in these processes since it regulates motivation, reward, motor control, and sexual behaviors. The goal of this study is to elucidate the role of dopamine in ethanol-associated behavioral disinhibition using the genetically tractable model system Drosophila melanogaster. Previous studies have shown a requirement for normal dopamine neurotransmission for ethanol-induced courtship disinhibition. Furthermore, genetic manipulation of the dopamine system revealed that D1 receptor activity is important for disinhibition and D2 for sensitization. The current study focuses …

Brainstorm: Head Injuries And The Nfl, Part 3: A History Of Terms – Characteristics Of Cte, John J. Medina Ph.D.

Brainstorm

Though repetitive closed­head injuries are often experienced in professional contact sports, many injuries are minor, with collisions involving the head an everyday experience of the sport. Collegiate football players can sustain anywhere from 400 to more than 2,400 head impacts per season, depending upon the player — and possibly his position. The athlete usually walks it off, or is examined and benched for a period of time, lives to play another day. Eventually he joins the NFL, retires, starts endorsing products, and, except for maybe gaining a few pounds, seems to suffer few ill effects.

Autism Spectrum Disorders In Hispanics And Non-Hispanics, Virginia Chaidez, Robin L. Hansen, Irva Hertz-Picciotto

Department of Nutrition and Health Sciences: Faculty Publications

Objectives: To compare differences in autism between Hispanics and non-Hispanics. We also examined the relationship between multiple language exposure and language function and scores of children. Methods: The Childhood Autism Risks from Genetics and the Environment (CHARGE) study is an ongoing population-based case-control study with children sampled (n = 1061) from three strata: those with autism (AU) or autism spectrum disorder (ASD); developmental delay (DD); or the general population (GP). Results: Non-Hispanic cases demonstrated higher cognitive composite scores for the Mullen Scales of Early Learning (MSEL). There were significant associations between multiple language exposure and MSEL subscales for receptive …

Coordination Between Proteasome Impairment And Caspase Activation Leading To Tau Pathology: Neuroprotection By Camp, M. J. Metcalfe, Q. Huang, Maria E. Figueiredo-Pereira

Publications and Research

Neurofibrillary tangles (NFTs) are hallmarks of Alzheimer’s disease (AD). The main component of NFTs is TAU, a highly soluble microtubule-associated protein. However, when TAU is cleaved at Asp421 by caspases it becomes prone to aggregation leading to NFTs. What triggers caspase activation resulting in TAU cleavage remains unclear. We investigated in rat cortical neurons a potential coordination between proteasome impairment and caspase activation. We demonstrate that upon proteasome inhibition, the early accumulation of detergent-soluble ubiquitinated (SUb) proteins paves the way to caspase activation and TAU pathology. This occurs with two drugs that inhibit the proteasome by different means: the product …

Evidence Accumulator Or Decision Threshold - Which Cortical Mechanism Are We Observing?, Patrick Simen

Faculty & Staff Scholarship

Most psychological models of perceptual decision making are of the accumulation-to- threshold variety. The neural basis of accumulation in parietal and prefrontal cortex is therefore a topic of great interest in neuroscience. In contrast, threshold mechanisms have received less attention, and their neural basis has usually been sought in subcortical structures. Here I analyze a model of a decision threshold that can be implemented in the same cortical areas as evidence accumulators, and whose behavior bears on two open questions in decision neuroscience: (1) When ramping activity is observed in a brain region during decision making, does it reflect evidence …

Brainstorm: Head Injuries And The Nfl, Part 2: A History Of Terms – Cte And Concussion, John J. Medina Ph.D.

Brainstorm

The history of research into the relationship between head injuries and contact sports starts not with football, but with boxing.

Focal Adhesion Kinase Modulates Cdc42 Activity Downstream Of Positive And Negative Axon Guidance Cues, Jonathan P. Myers, Estuardo Robles, Allison Ducharme-Smith, Timothy M. Gomez

Neuroscience: Faculty Publications

There is biochemical, imaging and functional evidence that Rho GTPase signaling is a crucial regulator of actin-based structures such as lamellipodia and filopodia. However, although Rho GTPases are believed to serve similar functions in growth cones, the spatiotemporal dynamics of Rho GTPase signaling has not been examined in living growth cones in response to known axon guidance cues. Here we provide the first measurements of Cdc42 activity in living growth cones acutely stimulated with both growth-promoting and growthinhibiting axon-guidance cues. Interestingly, we find that both permissive and repulsive factors can work by modulating Cdc42 activity, but in opposite directions. We …