ADAR1 deficiency protects against high-fat diet-induced obesity and insulin resistance in mice.

Obesity is an important independent risk factor for type 2 diabetes, cardiovascular diseases, and many other chronic diseases. The objective of this study was to determine the role of adenosine deaminase acting on RNA 1 (ADAR1) in the development of obesity and insulin resistance. Wild-type (WT) and heterozygous ADAR1-deficient () mice were fed normal chow or a high-fat diet (HFD) for 12 wk.

Age Dependency of Blood-Brain Barrier Penetration by and -Permethrin in the Rat.

Permethrin (PER), a type I pyrethroid, is the most widely used insecticide in domestic settings in the United States. The overall objective of this study was to assess the efficiency of the blood-brain barrier (BBB) as an obstacle to the C--permethrin (CIS) and C--permethrin (TRANS) isomers of PER, and to determine whether its barrier function changes during maturation of the rat. Experiments were conducted to quantify brain uptake of CIS and TRANS in postnatal day 145, 21, and 90 Sprague-Dawley rats.

Activity in nodose ganglia neurons after treatment with CP 55,940 and cholecystokinin.

Previous work has shown that cannabinoids increase feeding, while cholecystokinin (CCK) has an anorexigenic effect on food intake. Receptors for these hormones are located on cell bodies of vagal afferent nerves in the nodose ganglia. An interaction between CCK and endocannabinoid receptors has been suggested.

Agricultural Animals as Biomedical Models: Occupational Health and Safety Considerations.

The use of agricultural animals in biomedical research is increasing. Their overall size and metabolic rate, organ size, longer gestation period, and other physiological similarities make them good candidates for animal models of human disease. There are a number of special considerations for use of traditional farm animals for biomedical research.

Development and Use of an Interactive Computerized Dog Model to Evaluate Cranial Nerve Knowledge in Veterinary Students.

In veterinary medicine, the cognitive skills necessary to interpret neurological disorders from text-based case descriptions may not translate into the diagnostic capabilities required for clinical neurological patients. As live animals exhibiting certain specific neurological disorders are infrequent during a student's exposure to clinics, students may graduate without the experience necessary to make an accurate diagnosis in the field. To address this, we have developed a computerized simulated dog head that can exhibit cranial nerve dysfunctions and respond to specific testing procedures in a clinically accurate manner.

Chronic exercise confers neuroprotection in experimental autoimmune encephalomyelitis.

Multiple sclerosis (MS) is an autoimmune disease that affects the CNS, resulting in accumulated loss of cognitive, sensory, and motor function. This study evaluates the neuropathological effects of voluntary exercise in mice with experimental autoimmune encephalomyelitis (EAE), an animal model of MS. Two groups of C57BL/6J mice were injected with an emulsion containing myelin oligodendrocyte glycoprotein and then randomized to housing with a running wheel or a locked wheel.

Comparison of concentrations of γ-aminobutyric acid and glutamate in cerebrospinal fluid of dogs with idiopathic epilepsy with and without seizure-related magnetic resonance imaging hyperintense areas in the limbic system.

Objective: To investigate differences in CSF concentrations of excitatory and inhibitory neurotransmitters in dogs with and without T2-weighted (T2W) MRI hyperintense areas in the limbic system.

Sample: Archived CSF samples and stored brain MRI images of 5 healthy research dogs (group 1), 8 dogs with idiopathic epilepsy (IE) with no abnormal MRI findings (group 2), and 4 dogs with IE with hyperintense areas in the limbic system detected by means of T2W MRI (group 3).

Procedures: Archived CSF samples and stored MRI images obtained from all dogs were evaluated.

Effect of treatment with simvastatin and cyclosporine on neurotransmitter concentrations in cerebrospinal fluid after subarachnoid hemorrhage in dogs.

Objective: To measure concentrations of glutamate, aspartate, γ-aminobutyric acid (GABA), and glycine in CSF of dogs with experimentally induced subarachnoid hemorrhage (SAH) and to assess effects of cyclosporine and simvastatin on these concentrations.

Sample: CSF samples from 13 dogs.

Procedures: In a previous study, SAH was induced in dogs via 2 injections of autologous blood into the cerebellomedullary cistern 24 hours apart.

Assessment of plasma uracil-to-dihydrouracil concentration ratio as an indicator of dihydropyrimidine dehydrogenase activity in clinically normal dogs and dogs with neoplasia or renal insufficiency.

Objective: To determine and compare the ratio of uracil (U) to dihydrouracil (UH(2)) concentrations in plasma as an indicator of dihydropyrimidine dehydrogenase activity in clinically normal dogs and dogs with neoplasia or renal insufficiency.

Animals: 101 client- and shelter-owned dogs.

Procedures: Study dogs included 74 clinically normal dogs, 17 dogs with neoplasia, and 10 dogs with renal insufficiency.

PRTFDC1 is a genetic modifier of HPRT-deficiency in the mouse.

Lesch-Nyhan disease (LND) is a severe X-linked neurological disorder caused by a deficiency of hypoxanthine phosphoribosyltransferase (HPRT). In contrast, HPRT-deficiency in the mouse does not result in the profound phenotypes such as self-injurious behavior observed in humans, and the genetic basis for this phenotypic disparity between HPRT-deficient humans and mice is unknown. To test the hypothesis that HPRT deficiency is modified by the presence/absence of phosphoribosyltransferase domain containing 1 (PRTFDC1), a paralog of HPRT that is a functional gene in humans but an inactivated pseudogene in mice, we created transgenic mice that express human PRTFDC1 in wild-type and HPRT-deficient backgrounds.

Lesion of the lateral parabrachial nucleus attenuates the anorectic effect of peripheral amylin and CCK.

Amylin and CCK activate the area postrema (AP)/nucleus of the solitary tract (NTS) - lateral parabrachial nucleus (LPBN) - central amygdala (CeA) pathway. However, except for the brainstem structures the role of these nuclei for the anorectic effect of these peptides is not yet well characterized. The current study investigated the role of the LPBN in mediating the inhibitory effect of peripheral amylin and CCK on feeding behavior.

Fiber but not conjugated linoleic acid influences adiposity in dogs.

Feeding obese dogs a high-fiber food with or without added conjugated linoleic acid (CLA) resulted in reduced caloric consumption, reduced body weight, and a 3.3% reduction in body fat, whereas feeding a low-fiber food resulted in a comparable increase in caloric consumption and a 2.4% gain in body fat.

Area postrema-lesions increase operant responding to sucrose in rats.

Rats with lesions of the area postrema (APX) are known to exhibit an enhanced intake of highly palatable foods such as sweetened condensed milk and cookies. These observations suggest the possibility that APX rats find these foods more rewarding and will work harder to obtain these foods. Sham and APX rats were tested on fixed ratio (FR) and progressive ratio (PR) schedules.

Fumonisin B1-induced neurodegeneration in mice after intracerebroventricular infusion is concurrent with disruption of sphingolipid metabolism and activation of proinflammatory signaling.

Fumonisin B1 (FB1), a mycotoxin produced by Fusarium verticillioides, causes equine leukoencephalomalacia, a condition not reproduced in any other species. We hypothesized that direct exposure of murine brain to FB1 will result in neurotoxicity, characterized by biochemical and pathological alterations. The present study compared the toxicity of FB1 in mouse brain after an intracerebroventricular (icv) or subcutaneous (sc) infusion.

Cardiovascular drift is related to reduced maximal oxygen uptake during heat stress.

Introduction/purpose: This study investigated whether the progressive rise in heart rate (HR) and fall in stroke volume (SV) during prolonged, constant-rate, moderate-intensity exercise (cardiovascular drift, CVdrift) in a hot environment is associated with a reduction in VO(2max).

Methods: CVdrift was measured in nine male cyclists between 15 and 45 min of cycling at 60% VO(2max) in 35 degrees C that was immediately followed by measurement of VO(2max). VO(2max) also was measured after 15 min of cycling on a separate day, so that any change in VO(2max) between 15 and 45 min could be associated with the CVdrift that occurred during that time interval.

Dopamine overflow is increased in olfactory bulbectomized rats: an in vivo microdialysis study.

Olfactory bulbectomy (OBX) in rats produces behavioral, physiological, and neurochemical changes that resemble symptoms of depression in humans. The procedure thus serves as a rodent model of affective disorder. Many of the behavioral effects of OBX resemble psychomotor agitation.

Cannabinoid agonist, CP 55,940, facilitates intake of palatable foods when injected into the hindbrain.

Cannabinoids have been shown to influence food intake, and until recently, the neural pathways mediating these effects have remained obscure. It has been previously shown that intracerebroventricular injection of delta-9-tetrahydrocannabinol (Delta(9)-THC) causes increased consumption of palatable foods in rats, and we postulated the involvement of the hindbrain in this cannabinoid-induced food intake. Cannulated rats (both female and male groups) trained to consume sweetened condensed milk received either lateral or fourth ventricle injections of CP 55,940 and were presented with sweetened condensed milk 15 min after injection.

Central insulin potentiates eating elicited by 2-deoxy-D-glucose.

2-Deoxy-D-glucose (2DG) elicits glucoprivic food intake whether administered centrally or systemically. Insulin, on the other hand, elicits glucoprivic food intake when administered systemically but reduces food intake when administered centrally. The purpose of these experiments was to determine the interaction of centrally administered insulin with systemically administered 2DG on feeding.

Intracerebroventricular injection of fructose stimulates feeding in rats.

2-deoxy-D-glucose (2DG) inhibits glycolysis and stimulates food intake. Previous work suggests that fructose may attenuate the hyperglycemic and hypothermic effects of 2DG. The current study examined the effect of intracerebroventricular fructose on 2DG-induced feeding.

Area postrema lesions elevate NPY levels and decrease anxiety-related behavior in rats.

Intracerebroventricular administration of neuropeptide Y (NPY) has been shown to reduce anxiety-like effects in rodents and also profoundly alter feeding. The area postrema-lesioned (APX) rat model of food motivated behavior overconsumes palatable foods and expresses significantly higher levels of NPY in the hypothalamus than sham-lesioned control rats. For this reason, we examined APX rats in the open field test, which is a standard measure of anxiety- or fear-related behavior and also investigated NPY mRNA levels in the hippocampus, amygdala and hypothalamus.