Medicine and Health Sciences Commons^™

Neural Coding And Decoding, Alexander Dimitrov

Systems Science Friday Noon Seminar Series

Methods based on Rate Distortion theory have been successfully used to cluster stimuli and neural responses in order to study neural codes at a level of detail supported by the amount of available data. They approximate the joint stimulus-response distribution by quantizing paired stimulus-response observations into smaller reproductions of the stimulus and response spaces. An optimal quantization is found by maximizing an information-theoretic cost function subject to both equality and inequality constraints, in hundreds to thousands of dimensions. This analytical approach has several advantages over other current approaches:

• it yields the most informative approximation of the encoding scheme given the …

Selected Hormonal And Neurotransmitter Mechanisms Regulating, James L. Sartin, Joseph A. Daniel, Brian K. Whitlock, Robyn R. Wilborn

Brian K Whitlock, PhD, DVM, DACT

Appetite control is a major issue in normal growth and in suboptimal growth performance settings. A number of hormones, in particular leptin, activate or inhibit orexigenic or anorexigenic neurotransmitters within the arcuate nucleus of the hypothalamus, where feed intake regulation is integrated. Examples of appetite regulatory neurotransmitters are the stimulatory neurotransmitters neuropeptide Y (NPY), agouti-related protein (AgRP), orexin and melanin-concentrating hormone and the inhibitory neurotransmitter, melanocyte-stimulating hormone (MSH). Examination of messenger RNA (using in situ hybridization and realtime PCR) and proteins (using immunohistochemistry) for these neurotransmitters in ruminants has indicated that physiological regulation occurs in response to fasting for several …

Selected Hormonal And Neurotransmitter Mechanisms Regulating, James L. Sartin, Joseph A. Daniel, Brian K. Whitlock, Robyn R. Wilborn

Faculty Publications and Other Works -- Large Animal Clinical Sciences

Appetite control is a major issue in normal growth and in suboptimal growth performance settings. A number of hormones, in particular leptin, activate or inhibit orexigenic or anorexigenic neurotransmitters within the arcuate nucleus of the hypothalamus, where feed intake regulation is integrated. Examples of appetite regulatory neurotransmitters are the stimulatory neurotransmitters neuropeptide Y (NPY), agouti-related protein (AgRP), orexin and melanin-concentrating hormone and the inhibitory neurotransmitter, melanocyte-stimulating hormone (MSH). Examination of messenger RNA (using in situ hybridization and realtime PCR) and proteins (using immunohistochemistry) for these neurotransmitters in ruminants has indicated that physiological regulation occurs in response to fasting for several …

Fast, Flexible Function-On-Scalar Regression, With An Application To Brain Development, Philip T. Reiss, Lei Huang

Philip T. Reiss

No abstract provided.

Direct Inputs To Off Α And G9 Ganglion Cells From Aii Amacrine Cells In Rabbit Retina, Wei-Li Liu

Dissertations & Theses (Open Access)

In the mammalian retina, AII amacrine cells are essential in the rod pathway for dark-adapted vision. But they also have a “day job”, to provide inhibitory inputs to certain OFF ganglion cells in photopic conditions. This is known as crossover inhibition. Physiological evidence from several different labs implies that AII amacrine cells provide direct input to certain OFF ganglion cells. However, previous EM analysis of the rabbit retina suggests that the dominant output of the AII amacrine cell in sublamina a goes to OFF cone bipolar cells (Strettoi et al., 1992).

Two OFF ganglion cell types in the rabbit retina, …

Changes In Plasma Concentrations Of Leptin In Ewes During Pregnancy, Joseph A. Daniel, A B. Milam, M E. Gafnea, Brian K. Whitlock, D H. Keisler

Animal Science Publications and Other Works

Previous research has demonstrated circulating concentrations of leptin increase in ewes during mid pregnancy then decline in late pregnancy and early lactation. The objective of this study was to more narrowly define the timing of changes in circulating concentrations of leptin with pregnancy in ewes. Katahdin ewes (n= 19) located at latitude 34.275 and longitude -85.183 (Mount Berry, GA) were utilized. Blood samples were collected weekly via jugular veinpuncture beginning immediately before ram exposure on September 23 and continuing until 4 weeks post-lambing. Ewes were exposed to a ram fitted with a marking harness for a 63 day breeding season. …

Effect Of Leukemia Inhibitory Factor On Feed Intake And Body Temperature In Sheep, James L. Sartin, D L. Marks, Brian K. Whitlock, Joseph A. Daniel, Barbara P. Steele

Animal Science Publications and Other Works

Leukemia inhibitory factor (LIF) has been suggested to function as a potent inhibitor of feed intake in rodents. These studies were designed to determine whether LIF was found in the ovine hypothalamus and whether LIF inhibited feed intake in sheep. Sheep hypothalami were used to clone LIF to indicate presence of the gene in the hypothalamus. The sequence was similar to published data. Another group of sheep were provided intraventricular (ICV) cannulas and injected with doses of LIF at 250, 500, 1000 and 2500 ng per sheep, ICV. Feed intake was inhibited by the 1000 and 2500 ng dose (trt, …

Changes In Plasma Concentrations Of Growth Hormone And Luteinizing Hormone In Ewes Following Central And Peripheral Treatment With Kisspeptin, Brian K. Whitlock, Joseph A. Daniel, Barbara P. Steele, James L. Sartin

Animal Science Publications and Other Works

Kisspeptin (KP), a neuroendocrine regulator of gonadotropin releasing hormone, has been hypothesized as an integrator of nutrition and hormones critical to metabolism and regulation of reproduction. Recent evidence suggests growth hormone (GH) secretion may be influenced by KP. The objective of this study was to determine if the GH stimulatory effect of KP is due to actions on the hypothalamus or anterior pituitary gland in ewes. Adult ovariectomized ewes (n=8) were fitted with intracerebroventricular (ICV) cannula to facilitate central administration of experimental treatments. Ewes received one of eight treatments [four intravenously (IV) and four ICV]. Peripheral treatments [0 (Veh), 100, …

Effect Of Leukemia Inhibitory Factor On Feed Intake And Body Temperature In Sheep, James L. Sartin, D L. Marks, Brian K. Whitlock, Joseph A. Daniel, Barbara P. Steele

Brian K Whitlock, PhD, DVM, DACT

Leukemia inhibitory factor (LIF) has been suggested to function as a potent inhibitor of feed intake in rodents. These studies were designed to determine whether LIF was found in the ovine hypothalamus and whether LIF inhibited feed intake in sheep. Sheep hypothalami were used to clone LIF to indicate presence of the gene in the hypothalamus. The sequence was similar to published data. Another group of sheep were provided intraventricular (ICV) cannulas and injected with doses of LIF at 250, 500, 1000 and 2500 ng per sheep, ICV. Feed intake was inhibited by the 1000 and 2500 ng dose (trt, …

Changes In Plasma Concentrations Of Growth Hormone And Luteinizing Hormone In Ewes Following Central And Peripheral Treatment With Kisspeptin, Brian K. Whitlock, Joseph A. Daniel, Barbara P. Steele, James L. Sartin

Brian K Whitlock, PhD, DVM, DACT

Kisspeptin (KP), a neuroendocrine regulator of gonadotropin releasing hormone, has been hypothesized as an integrator of nutrition and hormones critical to metabolism and regulation of reproduction. Recent evidence suggests growth hormone (GH) secretion may be influenced by KP. The objective of this study was to determine if the GH stimulatory effect of KP is due to actions on the hypothalamus or anterior pituitary gland in ewes. Adult ovariectomized ewes (n=8) were fitted with intracerebroventricular (ICV) cannula to facilitate central administration of experimental treatments. Ewes received one of eight treatments [four intravenously (IV) and four ICV]. Peripheral treatments [0 (Veh), 100, …

Changes In Plasma Concentrations Of Leptin In Ewes During Pregnancy, Joseph A. Daniel, A B. Milam, M E. Gafnea, Brian K. Whitlock, D H. Keisler

Brian K Whitlock, PhD, DVM, DACT

Previous research has demonstrated circulating concentrations of leptin increase in ewes during mid pregnancy then decline in late pregnancy and early lactation. The objective of this study was to more narrowly define the timing of changes in circulating concentrations of leptin with pregnancy in ewes. Katahdin ewes (n= 19) located at latitude 34.275 and longitude -85.183 (Mount Berry, GA) were utilized. Blood samples were collected weekly via jugular veinpuncture beginning immediately before ram exposure on September 23 and continuing until 4 weeks post-lambing. Ewes were exposed to a ram fitted with a marking harness for a 63 day breeding season. …

Neural Substrates Of Reliability-Weighted Visual-Tactile Multisensory Integration, Michael S. Beauchamp, Siavash Pasalar, Tony Ro

Publications and Research

As sensory systems deteriorate in aging or disease, the brain must relearn the appropriate weights to assign each modality during multisensory integration. Using blood-oxygen level dependent functional magnetic resonance imaging of human subjects, we tested a model for the neural mechanisms of sensory weighting, termed “weighted connections.” This model holds that the connection weights between early and late areas vary depending on the reliability of the modality, independent of the level of early sensory cortex activity. When subjects detected viewed and felt touches to the hand, a network of brain areas was active, including visual areas in lateral occipital cortex, …

Eye Movement Measures Of Cognitive Control In Children With Tourette Syndrome, Cameron B. Jeter

Dissertations & Theses (Open Access)

Tourette Syndrome begins in childhood and is characterized by uncontrollable repetitive actions like neck craning or hopping and noises such as sniffing or chirping. Worst in early adolescence, these tics wax and wane in severity and occur in bouts unpredictably, often drawing unwanted attention from bystanders. Making matters worse, over half of children with Tourette Syndrome also suffer from comorbid, or concurrent, disorders such as attention deficit hyperactivity disorder (ADHD) and obsessive-compulsive disorder (OCD). These disorders introduce anxious thoughts, impulsivity, inattention, and mood variability that further disrupt children with Tourette Syndrome from focusing and performing well at school and home. …

Farm Focus - Spring 2010, Brian K. Whitlock, Matt Welborn, Maria Prado, Amy Plummer

Faculty Publications and Other Works -- Large Animal Clinical Sciences

No abstract provided.

Locus Of Control And The Age Difference In Free Recall From Episodic Memory, Paul Amrhein, Judith K. Bond, Derek Hamilton

Department of Psychology Faculty Scholarship and Creative Works

The authors investigated the relation of locus of control (LOC) to age differences in free-recall memory performance. Older and younger participants completed P. C. Duttweiler's (1984) Internal Control Index (ICI) and subsequently performed free-recall memory tasks. Compared with the younger participants, the older participants exhibited poorer recall with more intrusions and uncorrected repetition errors as well as reduced categorical clustering. For the older participants with less internal LOC, recall proportion and item-pair associative recall clustering were lower than for the older participants with more internal LOC. By contrast, the younger participants did not exhibit any LOC effects in their recall …

Dopamine Neuron Stimulating Actions Of A Gdnf Propeptide, Luke H. Bradley, Josh Fuqua, April Richardson, Jadwiga Turchan-Cholewo, Yi Ai, Kristen A. Kelps, John D. Glass, Xiuquan He, Zhiming Zhang, Richard Grondin, O. Meagan Littrell, Peter Huettl, Francois Pomerleau, Don M. Gash, Greg A. Gerhardt

Neuroscience Faculty Publications

BACKGROUND: Neurotrophic factors, such as glial cell line-derived neurotrophic factor (GDNF), have shown great promise for protection and restoration of damaged or dying dopamine neurons in animal models and in some Parkinson's disease (PD) clinical trials. However, the delivery of neurotrophic factors to the brain is difficult due to their large size and poor bio-distribution. In addition, developing more efficacious trophic factors is hampered by the difficulty of synthesis and structural modification. Small molecules with neurotrophic actions that are easy to synthesize and modify to improve bioavailability are needed.

METHODS AND FINDINGS: Here we present the neurobiological actions of dopamine …

Functional Generalized Linear Models With Images As Predictors, Philip T. Reiss, R. Todd Ogden

Philip T. Reiss

Functional principal component regression (FPCR) is a promising new method for regressing scalar outcomes on functional predictors. In this paper we present a theoretical justification for the use of principal components in functional regression. FPCR is then extended in two directions: from linear to the generalized linear modeling, and from univariate signal predictors to high-resolution image predictors. We show how to implement the method efficiently by adapting generalized additive model technology to the functional regression context. A technique is proposed for estimating simultaneous confidence bands for the coefficient function; in the neuroimaging setting, this yields a novel means to identify …

Farm Focus - Spring 2010, Brian K. Whitlock, Matt Welborn, Maria Prado, Amy Plummer

Brian K Whitlock, PhD, DVM, DACT

No abstract provided.

The Biology Of Reality Testing - Implications For Cognitive Education, Neil Greenberg

Neil Greenberg

• This report explores the proposition that teaching effectiveness can be enhanced by accommodating the key differences between two complementary and deeply engrained modes of reality testing, each predominantly centered in different hemispheres of the brain. • (1) Correspondence involves “reality-testing” of a percept, the cerebral representation of an experience in the world. • (2) Coherence involves “textualizing”, that is, reality-testing of a percept by how easily it relates to previous and ongoing parallel and collateral experiences. • Confidence in the validity of any percept throughout development is related to the interplay of these key processes. • As organisms develop, …

Safe Medication Use Among Hispanic College Students: Knowledge, Attitudes And Behaviors, Tania Guadalupe Quiroz

Open Access Theses & Dissertations

College students are at increased risk of medication errors. Research suggests that young adults are active users of over-the- counter (OTC) medications and other products that may increase the risk for negative health outcomes. Therefore, it is very important to analyze young adults' attitudes, beliefs, and behaviors about medication use among college students in order to provide them with the necessary information. Due to language and cultural factors, the issue is particularly relevant in U.S.-Mexico border communities. This casual-comparative study examined knowledge, attitudes, and behaviors regarding medication use among Hispanic college students. Data was collected through a survey developed by …

Robust Dynamic Balance Of Ap-1 Transcription Factors In A Neuronal Gene Regulatory Network., Gregory M Miller, Babatunde A Ogunnaike, James S Schwaber, Rajanikanth Vadigepalli

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

BACKGROUND: The octapeptide Angiotensin II is a key hormone that acts via its receptor AT1R in the brainstem to modulate the blood pressure control circuits and thus plays a central role in the cardiac and respiratory homeostasis. This modulation occurs via activation of a complex network of signaling proteins and transcription factors, leading to changes in levels of key genes and proteins. AT1R initiated activity in the nucleus tractus solitarius (NTS), which regulates blood pressure, has been the subject of extensive molecular analysis. But the adaptive network interactions in the NTS response to AT1R, plausibly related to the development of …

Lost In Translation?: An Essay On Law And Neuroscience, Stephen J. Morse

All Faculty Scholarship

The rapid expansion in neuroscientific research fuelled by the advent of functional magnetic resonance imaging [fMRI] has been accompanied by popular and scholarly commentary suggesting that neuroscience may substantially alter, and perhaps will even revolutionize, both law and morality. This essay, a contribution to, Law and Neuroscience (M. Freeman, Ed. 2011), will attempt to put such claims in perspective and to consider how properly to think about the relation between law and neuroscience. The overarching thesis is that neuroscience may indeed make some contributions to legal doctrine, practice and theory, but such contributions will be few and modest for the …

Sleep Well To Stay Safe: Ready For Primetime?, Mihai C. Teodorescu, Mariana Szklo-Coxe

Community & Environmental Health Faculty Publications

Commentary on Kling et al. Sleep problems and workplace injuries in Canada. Sleep 2010;33:611-618.

Virtual Environments And Sensory Integration: Effects Of Aging And Stroke, Nicoleta L. Bugnariu, Joyce Fung

All Faculty Scholarship

Research was carried out on the effects of aging and sensory motor defi cits following strokes with respect to the capacity of the central nervous system to resolve sensory confl icts created by Virtual Reality (VR). The results of this research demonstrate that VR can be a valuable tool for therapeutic interventions that require an adaptation to complex, multimodal environments. The rehabilitation protocols include balancing training in virtual environments.

Les études qui ont été menées sur les effets du vieillissement et des défi cits sensori-moteurs consé-cutivement aux accidents vasculaires cérébraux concernent la capacité du système nerveux cen-tral à résoudre les …

Comparison Of Affective Analgesia And Conditioned Place Preference Following Cholinergic Activation Of, Elena Schifirnet

Wayne State University Dissertations

Activation of the dopaminergic mesolimbic reward circuitry that originates in the ventral tegmental area (VTA) is postulated to preferentially suppress affective reactions to noxious stimuli (affective analgesia, AA). VTA dopamine neurons are activated via cholinergic inputs, and we have observed that microinjections of the acetylcholine agonist carbachol suppressed vocalizations of rats that occur following administration of brief (1 sec) tail-shocks (vocalization afterdischarges = VAD). VADs are a validated rodent model of pain affect. In addition, the capacity of carbachol to support reinforcement appears to be regionally dependent within VTA. Ikemoto and Wise (2002) reported that carbachol was self-administered in the …

The Biology Of Reality Testing - Implications For Cognitive Education, Neil Greenberg

Faculty Publications and Other Works -- Ecology and Evolutionary Biology

• This report explores the proposition that teaching effectiveness can be enhanced by accommodating the key differences between two complementary and deeply engrained modes of reality testing, each predominantly centered in different hemispheres of the brain. • (1) Correspondence involves “reality-testing” of a percept, the cerebral representation of an experience in the world. • (2) Coherence involves “textualizing”, that is, reality-testing of a percept by how easily it relates to previous and ongoing parallel and collateral experiences. • Confidence in the validity of any percept throughout development is related to the interplay of these key processes. • As organisms develop, …

Ganaxolone Suppression Of Behavioral And Electrographic Seizures In The Mouse Amygdala Kindling Model, Doodipala S. Reddy, Michael A. Rogawski

Michael A. Rogawski

Ganaxolone (3alpha-hydroxy-3alpha-methyl-5alpha-pregnan-20-one), a synthetic analog of the endogenous neurosteroid allopregnanolone and a positive allosteric modulator of GABA-A receptors, may represent a new treatment approach for epilepsy. Here we demonstrate that pretreatment with ganaxolone (1.25—20 mg/kg, s.c.) causes a dose-dependent suppression of behavioral and electrographic seizures in fully amygdala-kindled female mice, with nearly complete seizure protection at the highest dose tested. The ED50 for suppression of behavioral seizures was 6.6 mg/kg. The seizure suppression produced by ganaxolone was comparable to that of clonazepam (ED50, 0.1 mg/kg, s.c.). To the extent that amygdala kindling represents a model of mesial temporal lobe epilepsy, …

Neurosteroids On The Epilepsy Chessboard — Keeping Seizures In Check, Michael A. Rogawski

Michael A. Rogawski

No abstract provided.

Treatment Of Early And Late Kainic-Acid Induced Status Epilepticus With The Non-Competitive Ampa Receptor Antagonist Gyki 52466, Brita Fritsch, Jeffrey J. Stott, J. Joelle Donofrio, Michael A. Rogawski

Michael A. Rogawski

Purpose: Benzodiazepines such as diazepam may fail to effectively treat status epilepticus because benzodiazepine-sensitive GABA-A receptors are internalized progressively with continued seizure activity. Ionotropic glutamate receptors, including AMPA receptors, are externalized, so that AMPA receptor antagonists, which are broad-spectrum anticonvulsants, could be more effective treatments for satus epilepticus. We assessed the ability of the non-competitive AMPA receptor antagonist GYKI 52466 to protect against kainic acid-induced status epilepticus in mice. Methods: Groups of animals treated with kainic acid received GYKI 52466 (50 mg/kg followed in 15 min by 50 mg/kg) or diazepam (25 mg/kg followed in 20 min by 12.5 mg/kg) …

Anticonvulsant And Proconvulsant Actions Of 2-Deoxy-D-Glucose, Maciej Gasior, Jessica Yankura, Adam L. Hartman, Amy French, Michael A. Rogawski

Michael A. Rogawski

Purpose: 2-Deoxy-D-glucose (2-DG), a glucose analog that accumulates in cells and interferes with carbohydrate metabolism by inhibiting glycolytic enzymes, has anticonvulsant actions. Recognizing that severe glucose deprivation can induce seizures, we sought to determine whether acute treatment with 2-DG can promote seizure susceptibility by assessing its effects on seizure threshold. For comparison, we studied 3-methyl-glucose (3-MG), which like 2-DG accumulates in cells and reduces glucose uptake, but does not inhibit glycolysis. Methods: Mice were treated with 2-DG or 3-MG and the seizure threshold determined in the 6-Hz test, the mouse electroshock seizure threshold (MEST) test, and the intravenous pentylenetetrazol (i.v. …