Neuroscience and Neurobiology Commons^™

Brain Stimulation Reward Is Integrated By A Network Of Electrically-Coupled Gaba Neurons, Matthew Brian Lassen

Theses and Dissertations

Although it is well-established that animals will self-stimulate electric current to various diverse brain structures, the neural substrate of brain stimulation reward (BSR) has eluded identification since its discovery more than a half-century ago. We show that GABA neurons in the midbrain, hypothalamus and thalamus express connexin-36 (Cx36) gap junctions and couple electrically with dopamine application or by stimulation of the internal capsule (IC), which also supports self-stimulation. The threshold for responding for self-stimulation of the IC is the threshold for coupling between these GABA neurons, the degree of responding for IC ICSS is proportional to the magnitude of electrical …

Winter Behavior Of Big Brown Bats (Eptesicus Fuscus) In A Building Roost: Intermittent Feeding, Passive Rewarming, And Energy Conservation, Amy L. Fairbairn

All-Inclusive List of Electronic Theses and Dissertations

I investigated the use of torpor and arousals during winter of 2005 - 2006 by freeliving big brown bats (Eptesicus fuscus) by measuring skin temperature (remotely using data loggers) and used those measurements to estimate winter energy expenditure. Torpor bouts lasted for a mean of 3 .3 days ( d) with a mean of 3 .6 d and 2.2 d for males and females, respectively. There was no correlation between ambient temperature (Ta) during torpor and torpor bout length, but there was a significant correlation between Ta and length of the active period. Arousals lasted on average 5.0 hours (h). …

Prior Experience As A Stimulus Category Confound: An Example Using Facial Expressions Of Emotion, Leah H. Somerville, Paul J. Whalen

Dartmouth Scholarship

Facial expressions of emotion represent a stimulus set widely used to assess a broad range of psychological processes. However, a consideration of systematic differences between expression categories, other than differences relating to characteristics of the expressions themselves, has remained largely unaddressed. By collecting experience rankings in a large sample of undergraduates, we observed that the amount of reported experience individuals have had with different facial expressions of emotion systematically differed between all expression categories. These findings shed light on the potential for identifying confounds inherent to comparing some stimulus categories and, in this case, may aid in the interpretation of …

Comparative Perspectives On The Functions Of Sleep, John A. Lesku

All-Inclusive List of Electronic Theses and Dissertations

Previous comparative studies of sleep identified relationships between sleep and constitutive and ecological variables. Results from these studies helped shape early hypotheses for the function of sleep; however, all were conducted without an explicit phylogenetic or theoretic framework and focused exclusively on mammals. Hence, the validity of their results and applicability to other taxa is unclear. We ( 1) reviewed the literature on sleep in animals, (2) updated and reanalyzed the mammalian dataset using independent contrasts and (3) multivariate path analysis, and ( 4) presented the first quantitative analysis of sleep in a non-mammalian taxon: birds. Following previous mammalian analyses, …

Neuromechanics Of Multifunctionality During Rejection In Aplysia Californica, Hui Ye, Douglas W. Morton, Hillel J. Chiel

Faculty Scholarship

How are the same muscles and neurons used to generate qualitatively different behaviors? We studied this question by analyzing the biomechanical and neural mechanisms of rejection responses in the marine mollusk Aplysia californica and compared these mechanisms with those used to generate swallowing responses (Ye et al., 2006). During rejection, the central grasper of the feeding structure closes to push inedible food out of the buccal cavity. This contrasts with swallowing, during which the grasper is open as it moves toward the jaws (protracts). We examined how the shape change of the grasper during rejection mechanically reconfigured the surrounding musculature. …

Interval Timer Control Of Puberty In Photoinhibited Siberian Hamsters, Ho Park Jin, Alexander S. Kauffman, Matthew J. Paul, Matthew P. Butler, Annaliese K. Beery, Ruth M. Costantini, Irving Zucker

Neuroscience: Faculty Publications

Puberty, which is markedly delayed in male Siberian hamsters (Phodopus sungorus) born into short day lengths, is controlled by an interval timer regulated by the duration of nocturnal melatonin secretion. Properties of the interval timer were assessed by perturbing normal patterns of melatonin secretion in males gestated and maintained thereafter in 1 of 2 short day lengths, 10 h light/day (10L) or 12L. Melatonin secretion of short-day hamsters was suppressed by constant light treatment or modified by daily injection of propranolol to mimic nocturnal melatonin durations typical of long-day hamsters. Constant light treatment during weeks 3 to 5 induced early …

In Situ Muscle Power Differs Without Varying In Vitro Mechanical Properties In Two Insect Leg Muscles Innervated By The Same Motor Neuron, Anna N. Ahn, Kenneth Meijer, Robert J. Full

All HMC Faculty Publications and Research

The mechanical behavior of muscle during locomotion is often predicted by its anatomy, kinematics, activation pattern and contractile properties. The neuromuscular design of the cockroach leg provides a model system to examine these assumptions, because a single motor neuron innervates two extensor muscles operating at a single joint. Comparisons of the in situ measurements under in vivo running conditions of muscle 178 to a previously examined muscle (179) demonstrate that the same inputs (e.g. neural signal and kinematics) can result in different mechanical outputs. The same neural signal and kinematics, as determined during running, can result in different mechanical functions, …

Classification Of Neuronal Nicotinic Acetylcholine Receptors In Rat Ca1 Hippocampal Interneuron Subpopulations Defined By Calcium-Binding Protein Mrna Expression, Richard M. Burgon

Theses and Dissertations

In this study, the single-cell relative quantitative mRNA expression of three Calcium-binding proteins (CaBPs; calbindin, calretinin, parvalbumin) and eight nicotinic acetylcholine receptor (nAChR) subunits (alpha2-alpha5, alpha7, beta2-beta4) from interneurons from the stratum radiatum or stratum oriens within the CA1 region of rat hippocampi was analyzed using quantitative real time RT-PCR. Eighty-seven percent of the interneurons examined expressed CaBP mRNA. Parvalbumin mRNA was detected in 64%, while calbindin and calretinin expression was detected in 26% and 40% of interneurons, respectively. CaBP expression was not exclusive; the average number of CaBP mRNA detected per interneuron of the 47 interneurons examined for CaBP …

Exposure Of Nervous System Cells To Polychlorinated Biphenyls (Pcbs), Results In Alterations Of Neurotrophic Factor Expression, Gordon H. Gurley

Dissertations

Toxic insult by PCBs results in learning and memory deficits in humans. Alterations in expression of neurotrophic factors (NF) and/or their receptors have been linked to changes in learning and memory. How PCBs affect cognition is not known. We suggest that PCBs affect cognition by altering NF expression.

We exposed cultured C6 rat glioblastoma cells (an astrocyte cell-line) to medium containing PCB (Aroclor 1254 (10ppm)). Control cells were treated with dimethyl sulfoxide (DMSO) or regular medium. Enzyme-linked immunosorbent assays (ELISA) were used to determine glial cell-line derived neurotrophic factor(GDNF) and nerve growth factor (NGF) concentrations in all samples. We also …

Using Literature And Innovative Assessments To Ignite Interest And Cultivate Critical Thinking Skills In An Undergraduate Neuroscience Course, Eileen Lynd-Balta

Biology Faculty/Staff Publications

Science education reform initiatives emphasize 1) the value of concepts over facts; 2) the benefits of open-ended, inquiry-based problem-solving rather than protocols leading to a single correct answer; and 3) the importance of a multidisciplinary approach to teaching that is not confined by departmental boundaries. Neuroscientists should be at the forefront of this movement by the very nature of the discipline we study. Neuroscience is a relatively new field that integrates diverse subjects (anatomy, physiology, pharmacology, molecular biology, computer science, and psychology) and experimental advances are constantly changing and expanding our understanding of brain function. How can we convey this …

Dissociation Of Automatic And Strategic Lexical-Semantics: Functional Magnetic Resonance Imaging Evidence For Differing Roles Of Multiple Frontotemporal Regions, Brian T. Gold, David A. Balota, Sara J. Jones, David K. Powell, Charles D. Smith, Anders H. Andersen

Neuroscience Faculty Publications

Behavioral research has demonstrated three major components of the lexical-semantic processing system: automatic activation of semantic representations, strategic retrieval of semantic representations, and inhibition of competitors. However, these component processes are inherently conflated in explicit lexical-semantic decision tasks typically used in functional magnetic resonance imaging (fMRI) research. Here, we combine the logic of behavioral priming studies and the neurophysiological phenomenon of fMRI priming to dissociate the neural bases of automatic and strategic lexical-semantic processes across a series of three studies. A single lexical decision task was used in all studies, with stimulus onset asynchrony or linguistic relationship between prime and …

Medial Prefrontal Activity Differentiates Self From Close Others, Todd F. Heatherton, Carrie L. Wyland, C. Neil Macrae, Kathryn E. Demos, Bryan T. Denny, William M. Kelley

Dartmouth Scholarship

No abstract provided.

Previous Spatial Memory Training And Nicotine Administration Alleviates Cognitive Deficits Produced By Medial Frontal Cortex Lesions In Rats., Rachel L. Norris

Electronic Theses and Dissertations

Rats were administered nicotine (0.3 mg/kg) for 11 consecutive days before and after an electrolytic medial frontal cortex lesion. Behavioral testing was arranged so that the rats were tested on the RAM 1 day after drug administration followed by behavioral testing on the MWT 19 days after drug treatment, or tested on the MWT 1 day after drug administration followed by testing on the RAM4 days after drug treatment. Results of MWT testing showed that regardless of the drug/behavioral testing interval, lesioned rats given nicotine demonstrated enhancement relative to saline-treated animals. Results of RAM testing showed that nicotine improved performance …

Activation In Neural Networks Controlling Ingestive Behaviors: What Does It Mean, And How Do We Map And Measure It?, Alan Watts, Arshad Khan, Graciela Sanchez-Watts, Dawna Salter, Christina Neuner

Selected Works Temporary Series

No abstract provided.

Activation In Neural Networks Controlling Ingestive Behaviors: What Does It Mean, And How Do We Map And Measure It?, Watts, Arshad Khan, Graciela Sanchez-Watts, Dawna Salter, Christina Neuner

Departmental Papers (Biology)

No abstract provided.

Art Therapy With Adults With Autism, Kimberly Dennler

EVMS School of Health Professions Theses & Dissertations

Research regarding art therapy with adults with autism is limited. The objective of this study was to understand the effect of a specific art therapy intervention upon social interaction and communication of the adults with autism. The hypothesis was that by participating in this intervention, the participants’ communication and socialization would increase and their maladaptive behaviors would decrease. Over a series of nine sessions, the five participants from Bittersweet Farms were introduced to basic techniques for working with clay.

Results were based on qualitative analysis of data from staff surveys, through the use of pre and post questionnaires; observations made …

Prenatal Cocaine Exposure Alters Alpha2 Receptor Expression In Adolescent Rats, Rosemarie M. Booze, David R. Wallace, Janelle M. Silvers, Barbara J. Strupp, Diane M. Snow, Charles F. Mactutus

Neuroscience Faculty Publications

BACKGROUND: Prenatal cocaine exposure produces attentional deficits which to persist through early childhood. Given the role of norepinephrine (NE) in attentional processes, we examined the forebrain NE systems from prenatal cocaine exposed rats. Cocaine was administered during pregnancy via the clinically relevant intravenous route of administration. Specifically, we measured alpha2-adrenergic receptor (alpha2-AR) density in adolescent (35-days-old) rats, using [3H]RX821002 (5 nM).

RESULTS: Sex-specific alterations of alpha2-AR were found in the hippocampus and amygdala of the cocaine-exposed animals, as well as an upregulation of alpha2-AR in parietal cortex.

CONCLUSION: These data suggest that prenatal cocaine exposure results in a persistent alteration …

Cyclooxygenase-2 Mediates Microglial Activation And Secondary Dopaminergic Cell Death In The Mouse Mptp Model Of Parkinson's Disease, Rattanavijit Vijitruth, Mei Liu, Dong-Young Choi, Xuan V. Nguyen, Randy L. Hunter, Guoying Bing

Neuroscience Faculty Publications

BACKGROUND: Accumulating evidence suggests that inflammation plays an important role in the progression of Parkinson's disease (PD). Among many inflammatory factors found in the PD brain, cyclooxygenase (COX), specifically the inducible isoform, COX-2, is believed to be a critical enzyme in the inflammatory response. Induction of COX-2 is also found in an experimental model of PD produced by administration of 1-methy-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP).

METHOD: COX-2-deficient mice or C57BL/6 mice were treated with MPTP to investigate the effects of COX-2 deficiency or by using various doses of valdecoxib, a specific COX-2 inhibitor, which induces inhibition of COX-2 on dopaminergic neuronal toxicity and …

Fms-Like Tyrosine Kinase 3 Ligand Recruits Plasmacytoid Dendritic Cells To The Brain, James Curtin, Gwendalyn King, Carlos Barcia, Chunyan Liu, Francois Hubert, Carole Guillonneau, Regis Josien, Ignacio Anegon, Pedro Lowenstein, Maria Castro

Articles

The lack of professional afferent APCs in naive brain parenchyma contributes to the systemic immune ignorance to Ags localized exclusively within the brain. Dendritic cells (DCs) appear within the brain as a consequence of inflammation, but no molecular mechanisms accounting for this influx have been described. In this study we demonstrate that Fms-like tyrosine kinase 3 ligand (Flt3L) recruits plasmacytoid DCs (pDCs; >50-fold; p < 0.001) to the brain parenchyma. These pDCs expressed IFN-alpha, the hallmark cytokine produced by pDCs, indicating recruitment and activation in situ of bona fide pDCs within the brain parenchyma. Flt3L did not increase the numbers of conventional DCs, macrophages, or B, T, NK, NKT, or microglial cells within the brain. Our data demonstrate that Flt3L reconstitutes a crucial afferent component of the immune response, namely, professional APCs within the brain parenchyma, and this could counteract the intrinsic systemic immune ignorance to Ags localized exclusively within the brain.

Neuromechanics Of Coordination During Swallowing In Aplysia Californica, Hui Ye, Douglas W. Morton, Hillel J. Chiel

Faculty Scholarship

Bernstein (1967) hypothesized that preparation of the periphery was crucial for correct responses to motor output. To test this hypothesis in a behaving animal, we examined the roles of two identified motor neurons, B7 and B8, which contribute to feeding behavior in the marine mollusk Aplysia californica. Neuron B7 innervates a hinge muscle and has no overt behavioral effect during smaller-amplitude (type A) swallows, because the hinge muscle is too short to exert force. Neuron B8 activates a muscle (I4) that acts solely to grasp material during type A swallows. During larger-amplitude (type B) swallows, the behavioral actions of both …

Broad, Deep And Indirect: The Potential Influence Of Neuroscience In Law, Amanda C. Pustilnik

Faculty Scholarship

No abstract provided.

An Optimal Brain Can Be Composed Of Conflicting Agents, Adi Livnat, Nicholas Pippenger

All HMC Faculty Publications and Research

Many behaviors have been attributed to internal conflict within the animal and human mind. However, internal conflict has not been reconciled with evolutionary principles, in that it appears maladaptive relative to a seamless decision-making process. We study this problem through a mathematical analysis of decision-making structures. We find that, under natural physiological limitations, an optimal decision-making system can involve “selfish” agents that are in conflict with one another, even though the system is designed for a single purpose. It follows that conflict can emerge within a collective even when natural selection acts on the level of the collective only.

Neuroscholar’S Electronic Laboratory Notebook And Its Application To Neuroendocrinology, Arshad Khan, Joel Hahn, We-Cheng Cheng, Alan Watts, Gully Burns

Selected Works Temporary Series

No abstract provided.

Behavioral And Neurochemical Responses To Cocaine In Periadolescent And Adult Rats, Laura O'Dell

Selected Works Temporary Series

No abstract provided.

Corticotropin-Releasing Factor Within The Central Nucleus Of The Amygdala Mediates Enhanced Ethanol Self-Administration In Ethanol-Dependent Rats During Withdrawal., Laura O'Dell

Selected Works Temporary Series

No abstract provided.

Biphasic Alterations In Serotonin1b (5-Ht1b) Receptor Function During Abstinence From Extended Cocaine Self-Administration, Laura O'Dell

Selected Works Temporary Series

No abstract provided.

Diminished Nicotine Withdrawal In Adolescent Rats: Implications For Vulnerability To Addiction, Laura O'Dell

Selected Works Temporary Series

No abstract provided.

Extended Access To Nicotine Self-Administration Leads To Dependence: Circadian Measures, Withdrawal Measures, And Extinction Behavior In Rats, Laura O'Dell

Selected Works Temporary Series

No abstract provided.

Unlimited Access To Heroin Self-Administration: Independent Motivational Markers Of Opiate Dependence, Laura O'Dell

Selected Works Temporary Series

No abstract provided.

Word Association Tests Of Associative Memory And Implicit Processes: Theoretical And Assessment Issues, Alan W. Stacy, Susan L. Ames, Jerry L. Grenard

CGU Faculty Publications and Research

Word association is one of the most commonly used measures of association in cognitive science. These tests have been used to infer association parameters in normative studies, to derive cues and primes used in diverse paradigms (semantic priming, cued recall, illusory memory), to test implicit memory in experimental studies, and to suggest the operation of implicit processes in nonexperimental work. This chapter briefly outlines some of the historical routes and current controversies about association and summarizes basic cognitive research applying associative tests. The authors then describe benefits and limitations of the tests, as well as implications for theory and interventions …