Neuroscience and Neurobiology Commons^™

Alternation Rate In Perceptual Bistability Is Maximal At And Symmetric Around Equi-Dominance, Rubén Moreno-Bote, Asya Shpiro, John Rinzel, Nava Rubin

Publications and Research

When an ambiguous stimulus is viewed for a prolonged time, perception alternates between the different possible interpretations of the stimulus. The alternations seem haphazard, but closer inspection of their dynamics reveals systematic properties in many bistable phenomena. Parametric manipulations result in gradual changes in the fraction of time a given interpretation dominates perception, often over the entire possible range of zero to one. The mean dominance durations of the competing interpretations can also vary over wide ranges (from less than a second to dozens of seconds or more), but finding systematic relations in how they vary has proven difficult. Following …

Supersizing The Mind: Embodiment, Action And Cognitive Extension, Mirko Farina

Mirko Farina

No abstract provided.

Genetic Analysis Of The Function Of The Drosophila Doublesex-Related Factor Dmrt93b, Diana O'Day

Dissertations & Theses (Open Access)

DMRT (Doublesex and Mab-3 related transcription factor) proteins generally associated with sexual differentiation in many organisms share a common DNA binding domain and are often expressed in reproductive tissues. Aside from doublesex, which is a central factor in the regulation of sex determination, Drosophila possesses three different dmrt genes that are of unknown function. Because the association with sexual differentiation and reproduction is not universal and some DMRT proteins have been found to play other developmental roles we chose to further characterize one of these Drosophila genes. We carried out genetic analysis of dmrt93B, which was previously found to be …

Fibrinolytic Proteins And Brain-Derived Neurotrophic Factor Modulation Of Suprachiasmatic Nucleus Circadian Clock, Xiang Mou

Doctoral Dissertations

Mammalian circadian rhythms are controlled by a clock located in the suprachiasmatic nucleus (SCN). The mechanisms through which light phase-shifts the SCN circadian clock are similar to those underlying memory formation and long-term potentiation (LTP). Several secreted proteins, including tissue-type plasminogen activator (tPA), plasminogen, and brain-derived neurotrophic factor (BDNF), have been implicated in this process. These same proteins are important for photic phase-shifts of the SCN circadian clock. Early night glutamate application to SCN containing brain slices resets the circadian clock. Our experiments find that the endogenous tPA inhibitor, plasminogen activator inhibitor 1(PAI-1), blocked these shifts in slices from wildtype …

Neuroprotective Effects Of Anthocyanins On Neuronal Death Induced By Inhibition Of Bcl-2 And Oxidative Stress, Natalie A. Kelsey

Electronic Theses and Dissertations

Neurodegenerative diseases such as Parkinson’s and amyotrophic lateral sclerosis have devastating consequences to the afflicted patients. A major cellular pathophysiology underlying these diseases is mitochondrial oxidative stress (MOS) leading to neuronal death. Here, we investigated the neuroprotective effects of a novel class of nutraceuticals, anthocyanins, against MOS-induced death in primary cultures of rat cerebellar granule neurons (CGNs). Anthocyanins are natural antioxidants whose neuroprotective potential has yet to be examined in detail. Kuromanin and callistephin are anthocyanins derived from black rice and strawberries, respectively. Glutathione (GSH)-sensitive MOS and intrinsic apoptosis were induced in CGNs by the Bcl-2 inhibitor, HA14-1. Callistephin and …

Overexpression Of Amyloid Precursor Protein Induces Mitochondrial Oxidative Stress And Activates The Intrinsic Apoptosis Pathway, Matthew G. Bartley

Electronic Theses and Dissertations

Down syndrome (DS) is the most common genetic form of cognitive disability and is caused by trisomy of chromosome 21. Within chromosome 21 is the gene, amyloid precursor protein (APP). Proteolysis of APP into toxic and aggregate-prone, beta-amyloid fragments underlies the pathophysiology of Alzheimer's disease (AD). Individuals with DS develop the neuropathology that can be diagnosed as AD; however, the role of APP overexpression in this comorbidity is presently unclear. Here, we elucidated the mechanism of cell death induced by overexpression of wild type APP. Chinese hamster ovary cells transfected with a DsRed-APP fusion construct displayed caspase-3 activation and nuclear …

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, …

Presenilin Is Necessary For The Function Of Cbp In The Adult Drosophila Cns, Randy S. Boyles

UNLV Theses, Dissertations, Professional Papers, and Capstones

Dominant mutations in Presenilin (Psn) have been correlated with the formation of Aß- containing plaques in patients with inherited forms of Alzheimer's disease (AD). However, a clear mechanism directly linking amyloid plaques to the pathology of familial or sporadic forms of AD has remained elusive. Thus, recent discoveries of several new substrates for Psn protease activity have sparked alternative hypotheses to explain the preclinical symptoms of AD. CBP (CREB-binding protein) is a haplo- insufficient transcriptional co-activator with histone acetyltransferase (HAT) activity that has been proposed to be a downstream target for Psn signaling. Individuals with reduced CBP levels have cognitive …

Neuropsychological And Emotion Processing Abnormalities In Bipolar Disorder I And Ii, Carol Randall

UNLV Theses, Dissertations, Professional Papers, and Capstones

Bipolar disorder illness is marked by emotional lability and mood disturbance, as well as various neuropsychological deficits, and the neuroanatomical correlates of many of these deficits are beginning to be identified. Numerous studies have implicated specific cortical and sub-cortical abnormalities in areas associated with executive function, memory, motor function, and the processing of emotion. Although a large body of research has been devoted to the investigation of cognitive and emotion-processing deficits in bipolar disorder, relatively few studies have been devoted to the investigation of how these deficits differ among bipolar disorder subtypes. This is surprising in light of known symptomatological …

Pharmacological And Genetic Reversal Of Age-Dependent Cognitive Deficits Attributable To Decreased Presenilin Function, S. M.J. Mcbride, C. H. Choi, B. P. Schoenfeld, A. J. Bell, D. A. Liebelt, D. Ferreiro, R. J. Choi, P. Hinchey, M. Kollaros, A. M. Terlizzi, N. J. Ferrick, E. Koenigsberg, R. L. Rudominer, A. Sumida, S. Chiorean, Kathleen King Siwicki, H. T. Nguyen, M. E. Fortini, T. V. Mcdonald, T. A. Jongens

Biology Faculty Works

Alzheimer's disease (AD) is the leading cause of cognitive loss and neurodegeneration in the developed world. Although its genetic and environmental causes are not generally known, familial forms of the disease (FAD) are attributable to mutations in a single copy of the Presenilin (PS) and amyloid precursor protein genes. The dominant inheritance pattern of FAD indicates that it may be attributable to gain or change of function mutations. Studies of FAD-linked forms of presenilin (psn) in model organisms, however, indicate that they are loss of function, leading to the possibility that a reduction in PS activity might contribute to FAD …

Acute Responses To Estradiol Replacement In The Olfactory System Of Apoe-Deficient And Wild-Type Mice, Britto P. Nathan, Michael Tonsor, Robert G. Struble

Britto P. Nathan

Epidemiological studies suggest that estrogen therapy protects against clinical expression of chronic neurological diseases. These beneficial effects of estrogen therapy are highly modified by apolipoprotein E (apoE) through an unknown mechanism. We examined the short-term effects of estradiol replacement in ovariectomized mice on apoE expression and markers for cell proliferation, reactive gliosis, neuronal maturation, and synaptogenesis in the primary olfactory pathway of wild-type (WT) and apoE knockout (KO) mice. Three days of estradiol replacement increased apoE expression in the olfactory nerve and in the glomerular layer. Estradiol treatment also increased cell proliferation, total cell numbers, number of mature neurons in …

Acute Responses To Estradiol Replacement In The Olfactory System Of Apoe-Deficient And Wild-Type Mice, Britto P. Nathan, Michael Tonsor, Robert G. Struble

Faculty Research & Creative Activity

Epidemiological studies suggest that estrogen therapy protects against clinical expression of chronic neurological diseases. These beneficial effects of estrogen therapy are highly modified by apolipoprotein E (apoE) through an unknown mechanism. We examined the short-term effects of estradiol replacement in ovariectomized mice on apoE expression and markers for cell proliferation, reactive gliosis, neuronal maturation, and synaptogenesis in the primary olfactory pathway of wild-type (WT) and apoE knockout (KO) mice. Three days of estradiol replacement increased apoE expression in the olfactory nerve and in the glomerular layer. Estradiol treatment also increased cell proliferation, total cell numbers, number of mature neurons in …

Acute Responses To Estradiol Replacement In The Olfactory System Of Apoe-Deficient And Wild-Type Mice, Britto Nathan, Michael Tonsor, Robert Struble

Faculty Research & Creative Activity

Epidemiological studies suggest that estrogen therapy protects against clinical expression of chronic neurological diseases. These beneficial effects of estrogen therapy are highly modified by apolipoprotein E (apoE) through an unknown mechanism. We examined the short-term effects of estradiol replacement in ovariectomized mice on apoE expression and markers for cell proliferation, reactive gliosis, neuronal maturation, and synaptogenesis in the primary olfactory pathway of wild-type (WT) and apoE knockout (KO) mice. Three days of estradiol replacement increased apoE expression in the olfactory nerve and in the glomerular layer. Estradiol treatment also increased cell proliferation, total cell numbers, number of mature neurons in …

Striatal Microrna Controls Cocaine Intake Through Creb Signalling, Jonathan A. Hollander, Heh-In Im, Antonio L. Amelio, Jannet Kocerha, Purva Bali, Qun Lu, David Willoughby, Claes Wahlestedt, Michael D. Conkright, Paul J. Kenny

Jannet Kocerha

Cocaine addiction is characterized by a gradual loss of control over drug use, but the molecular mechanisms regulating vulnerability to this process remain unclear. Here we report that microRNA-212 (miR-212) is upregulated in the dorsal striatum of rats with a history of extended access to cocaine. Striatal miR-212 decreases responsiveness to the motivational properties of cocaine by markedly amplifying the stimulatory effects of the drug on cAMP response element binding protein (CREB) signalling. This action occurs through miR-212-enhanced Raf1 activity, resulting in adenylyl cyclase sensitization and increased expression of the essential CREB co-activator TORC (transducer of regulated CREB; also known …

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. …