Search results for " Long-Evans"
showing 10 items of 20 documents
The pituitary gland prevents shock-associated death by controlling multiple inflammatory mediators
2018
Abstract Bacterial infections cause a major burden of disease worldwide. Sepsis and septic shock are life-threatening complications of infections. The hypothalamic-pituitary-adrenal (HPA) axis initiates the release of endogenous glucocorticoids that modulate the host stress response and acute inflammation during septic shock. It is an ongoing controversial debate, if therapeutic manipulations of the HPA axis could benefit the clinical situation in the context of shock. Here, we have studied Long Evans rats with hypophysectomy followed by endotoxic shock. The shock-associated lethality was substantially higher in hypophysectomized rats as compared to control mice after cranial sham surgery (…
Behavioral and Cortical Correlates of Self-Suppression, Anticipation, and Ambivalence in Rat Tickling.
2019
The relationship between tickling, sensation, and laughter is complex. Tickling or its mere anticipation makes us laugh, but not when we self-tickle. We previously showed rat somatosensory cortex drives tickling-evoked vocalizations and now investigated self-tickle suppression and tickle anticipation. We recorded somatosensory cortex activity while tickling and touching rats and while rats touched themselves. Allo-touch and tickling evoked somatotopic cortical excitation and vocalizations. Self-touch induced wide-ranging inhibition and vocalization suppression. Self-touch also suppressed vocalizations and cortical responses evoked by allo-touch or cortical microstimulation. We suggest a glo…
Assessing the Impact of Single-Cell Stimulation on Local Networks in Rat Barrel Cortex—A Feasibility Study
2019
In contrast to the long-standing notion that the role of individual neurons in population activity is vanishingly small, recent studies have shown that electrical activation of only a single cortical neuron can have measurable effects on global brain state, movement, and perception. Although highly important for understanding how neuronal activity in cortex is orchestrated, the cellular and network mechanisms underlying this phenomenon are unresolved. Here, we first briefly review the current state of knowledge regarding the phenomenon of single-cell induced network modulation and discuss possible underpinnings. Secondly, we show proof of principle for an experimental approach to elucidate …
Cognitive deficits in aged rats correlate with levels of l-arginine, not with nNOS expression or 3,4-DAP-evoked transmitter release in the frontopari…
2005
Aging is associated with altered neurotransmitter function in the brain. In this study, we measured release parameters for acetylcholine (ACh), norepinephrine and serotonin in the frontoparietal cortex of young and aged rats. We also determined cortical amino acid concentrations and nitric oxide (NO) synthase function. Prior to sacrifice, the rats had been tested for Morris water-maze performance. In aged, compared with young rats, we observed a reduction in both uptake of choline and acetylcholine release. Serotonin release and L-arginine concentrations (a precursor of NO) showed an aging-related increase; however, L-citrulline/L-arginine ratios were decreased in aged rats. Moreover, while…
A Neuroprotective Function for the Hematopoietic Protein Granulocyte-Macrophage Colony Stimulating Factor (GM-CSF)
2007
Granulocyte-macrophage colony-stimulating factor (GM-CSF) is a hematopoietic cytokine responsible for the proliferation, differentiation, and maturation of cells of the myeloid lineage, which was cloned more than 20 years ago. Here we uncovered a novel function of GM-CSF in the central nervous system (CNS). We identified the GM-CSF α-receptor as an upregulated gene in a screen for ischemia-induced genes in the cortex. This receptor is broadly expressed on neurons throughout the brain together with its ligand and induced by ischemic insults. In primary cortical neurons and human neuroblastoma cells, GM-CSF counteracts programmed cell death and induces BCL-2 and BCL-Xl expression in a dose- a…
Decreasing dietary linoleic acid promotes long chain omega-3 fatty acid incorporation into rat retina and modifies gene expression
2011
International audience; Age-related macular degeneration (AMD) may be partially prevented by dietary habits privileging the consumption of ω3 long chain polyunsaturated fatty acids (ω3s) while lowering linoleic acid (LA) intake. The present study aimed to document whether following these epidemiological guidelines would enrich the neurosensory retina and RPE with ω3s and modulate gene expression in the neurosensory retina. Rat progenitors and pups were fed with diets containing low or high LA, and low or high ω3s. After scotopic single flash and 8-Hz-Flicker electroretinography, rat pups were euthanized at adulthood. The fatty acid profile of the neurosensory retina, RPE, liver, adipose tis…
Inhibition of adult hippocampal neurogenesis disrupts contextual learning but spares spatial working memory, long-term conditional rule retention and…
2009
Neurogenesis in the adult dentate gyrus (DG) of the hippocampus has been implicated in neural plasticity and cognition but the specific functions contributed by adult-born neurons remain controversial. Here, we have explored the relationship between adult hippocampal neurogenesis and memory function using tasks which specifically require the participation of the DG. In two separate experiments several groups of rats were exposed to fractionated ionizing radiation (two sessions of 7 Gy each on consecutive days) applied either to the whole brain or focally, aiming at a region overlying the hippocampus. The immunocytochemical assays showed that the radiation significantly reduced the expressio…
Drug gastrointestinal absorption in rat: Strain and gender differences.
2015
Predictive animal models of intestinal drug absorption are essential tools in drug development to identify compounds with promising biopharmaceutical properties. In situ perfusion absorption studies are routinely used in the preclinical setting to screen drug candidates. The objective of this work is to explore the differences in magnitude and variability on intestinal absorption associated with rat strain and gender. Metoprolol and Verapamil absorption rate coefficients were determined using the in situ closed loop perfusion model in four strains of rats and in both genders. Strains used were Sprague-Dawley, Wistar-Han, Wistar-Unilever, Long-Evans and CD∗IGS. In the case of Metoprolol only…
Effect of 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) on Hormones of Energy Balance in a TCDD-Sensitive and a TCDD-Resistant Rat Strain
2014
One of the hallmarks of the acute toxicity of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) is a drastically reduced feed intake by an unknown mechanism. To further elucidate this wasting syndrome, we followed the effects of a single large dose (100 μg/kg) of TCDD on the serum levels of several energy balance-influencing hormones, clinical chemistry variables, and hepatic aryl hydrocarbon receptor (AHR) expression in two rat strains that differ widely in their TCDD sensitivities, for up to 10 days. TCDD affected most of the analytes in sensitive Long-Evans rats, while there were few alterations in the resistant Han/Wistar strain. However, analyses of feed-restricted unexposed Long-Evans rats i…
The hippocampal dentate gyrus is essential for generating contextual memories of fear and drug-induced reward
2008
The hippocampus is believed to play a role in processing information relative to the context in which emotionally salient experiences occur but evidence on the specific contribution of the hippocampal dentate gyrus (DG) to these processes is limited. Here, we have used two classical behavioral paradigms to study the participation of the dorsal DG in context-conditioned reward and context-conditioned fear. Rats received intra-hippocampal vehicle or colchicine injections (4 μg/μl solution; 0.2 μl injections at 10 sites) that damaged the DG but spared other hippocampal subfields. In the first experiment, we used a place conditioning procedure pairing cocaine exposure (20 mg/kg, i.p.) with a sp…