Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 6 de 6
Filter
Add more filters










Database
Language
Publication year range
1.
J Am Assoc Lab Anim Sci ; 57(4): 328-334, 2018 07 01.
Article in English | MEDLINE | ID: mdl-30049297

ABSTRACT

Some performance standards for continuous trio breeding in 'shoebox' cages for inbred stocks and outbred strains of mice challenge the minimum floor space recommendations in the 8th edition of the Guide for the Care and Use of Laboratory Animals. In our study, we evaluated whether continuous trio breeding could be successfully applied to a breeding colony of genetically engineered mice housed in shoebox cages with a floor area of 67.6 in2. Mice heterozygous for genetically engineered mutations to estrogen receptors and their wildtype counterparts were continuously bred as trios or pairs. Confounding environmental factors were controlled through standardized husbandry practices and husbandry, and all mice were bred simultaneously to control for temporal factors. Several measures of reproductive performance-including number of litters per female, production index, interlitter interval, litter size at birth, litter size at weaning, weaning rate, and body weight of pups at weaning- were evaluated over approximately 6 mo. Regardless of genotype, interlitter interval, litter size at birth, and litter size at weaning were significantly lower for trio-bred mice than for pair-bred mice. In addition, significant interactions emerged between genotype and breeding strategy for these reproductive measures. Furthermore, significant differences between genotypes occurred for interlitter interval and weaning rate, regardless of breeding strategy. Underlying mechanisms to account for effects of genotype on interlitter interval and the interaction of genotype with breeding strategy were unclear but may reflect effects of overcrowding and reproductive suppression.


Subject(s)
Animal Husbandry , Animals, Laboratory , Breeding , Housing, Animal , Receptors, Estrogen/genetics , Animals , Body Weight , Female , Genotype , Litter Size , Mice , Mice, Knockout , Pregnancy , Reproduction/drug effects , Weaning
2.
Antioxid Redox Signal ; 22(2): 109-20, 2015 Jan 10.
Article in English | MEDLINE | ID: mdl-25226217

ABSTRACT

AIMS: Peroxisomes are highly adaptable and dynamic organelles, adjusting their size, number, and enzyme composition to changing environmental and metabolic demands. We determined whether peroxisomes respond to ischemia, and whether peroxisomal biogenesis is an adaptive response to cerebral ischemia. RESULTS: Focal cerebral ischemia induced peroxisomal biogenesis in peri-infarct neurons, which was associated with a corresponding increase in peroxisomal antioxidant enzyme catalase. Peroxisomal biogenesis was also observed in primary cultured cortical neurons subjected to ischemic insult induced by oxygen-glucose deprivation (OGD). A catalase inhibitor increased OGD-induced neuronal death. Moreover, preventing peroxisomal proliferation by knocking down dynamin-related protein 1 (Drp1) exacerbated neuronal death induced by OGD, whereas enhancing peroxisomal biogenesis pharmacologically using a peroxisome proliferator-activated receptor-alpha agonist protected against neuronal death induced by OGD. INNOVATION: This is the first documentation of ischemia-induced peroxisomal biogenesis in mammalian brain using a combined in vivo and in vitro approach, electron microscopy, high-resolution laser-scanning confocal microscopy, and super-resolution structured illumination microscopy. CONCLUSION: Our findings suggest that neurons respond to ischemic injury by increasing peroxisome biogenesis, which serves a protective function, likely mediated by enhanced antioxidant capacity of neurons.


Subject(s)
Catalase/metabolism , Dynamins/metabolism , Animals , Blotting, Western , Cell Survival/genetics , Cell Survival/physiology , Dynamins/genetics , Glucose/metabolism , Immunohistochemistry , Male , Mice , Mice, Inbred C57BL , Microscopy, Confocal , Oxygen/metabolism
3.
Metab Brain Dis ; 26(2): 123-33, 2011 Jun.
Article in English | MEDLINE | ID: mdl-21472429

ABSTRACT

Stroke induces a biphasic effect on the peripheral immune response that involves early activation of peripheral leukocytes followed by severe immunosuppression and atrophy of the spleen. Peripheral immune cells, including T lymphocytes, migrate to the brain and exacerbate the developing infarct. Recombinant T-cell receptor (TCR) Ligand (RTL)551 is designed as a partial TCR agonist for myelin oligodendrocyte glycoprotein (MOG)-reactive T cells and has demonstrated the capacity to limit infarct volume and inflammation in brain when administered to mice undergoing middle cerebral artery occlusion (MCAO). The goal of this study was to determine if RTL551 could retain protection when given within the therapeutically relevant 4 h time window currently in clinical practice for stroke patients. RTL551 was administered subcutaneously 4 h after MCAO, with repeated doses every 24 h until the time of euthanasia. Cell numbers were assessed in the brain, blood, spleen and lymph nodes and infarct size was measured after 24 and 96 h reperfusion. RTL551 reduced infarct size in both cortex and striatum at 24 h and in cortex at 96 h after MCAO and inhibited the accumulation of inflammatory cells in brain at both time points. At 24 h post-MCAO, RTL551 reduced the frequency of the activation marker, CD44, on T-cells in blood and in the ischemic hemisphere. Moreover, RTL551 reduced expression of the chemokine receptors, CCR5 in lymph nodes and spleen, and CCR7 in the blood and lymph nodes. These data demonstrate effective treatment of experimental stroke with RTL551 within a therapeutically relevant 4 h time window through immune regulation of myelin-reactive inflammatory T-cells.


Subject(s)
Brain , Infarction, Middle Cerebral Artery , Myelin Proteins , Receptors, Antigen, T-Cell/agonists , Recombinant Fusion Proteins/therapeutic use , Animals , Blood/immunology , Blood/metabolism , Brain/immunology , Brain/metabolism , Disease Models, Animal , Humans , Hyaluronan Receptors/immunology , Hyaluronan Receptors/metabolism , Infarction, Middle Cerebral Artery/pathology , Infarction, Middle Cerebral Artery/therapy , Lymph Nodes/immunology , Lymph Nodes/metabolism , Male , Mice , Mice, Inbred C57BL , Myelin Proteins/agonists , Myelin Proteins/immunology , Myelin-Oligodendrocyte Glycoprotein , Receptors, Antigen, T-Cell/immunology , Receptors, CCR5/immunology , Receptors, CCR5/metabolism , Receptors, CCR7/immunology , Receptors, CCR7/metabolism , Spleen/immunology , Spleen/metabolism , T-Lymphocytes/immunology , Time Factors , Treatment Outcome
4.
Lab Anim (NY) ; 38(9): 305-10, 2009 Sep.
Article in English | MEDLINE | ID: mdl-19701181

ABSTRACT

In order to efficiently generate genetically engineered mouse (GEM) fetuses or neonates of a specified age range, researchers must develop strain-specific strategies, including reliable early pregnancy detection. The authors evaluated pregnancy indices (pregnancy rate, plug rate, pregnant plugged rate, first litter size and body weight) in two GEM breeding colonies: homozygous soluble epoxide hydrolase knockout (sEHKO) mice (n=164 females) and L7-tau-green fluorescent protein (GFP) transgenic mice (n=61 females). The goals of the study were to determine the most accurate early pregnancy indicator and to reliably and cost-effectively produce timed pregnant females that were between gestation days 16 and 18. The authors set up each timed mating by placing two naturally synchronized females with a male for 48 h. When males were present, personnel checked each female daily for a vaginal plug. They then weighed the females immediately, 1 week and 2 weeks after removing the males. In both sEHKO and GFP colonies, increases in body weight at 1 and 2 weeks after timed male exposure more reliably and consistently indicated pregnancy than did plug detection. Further evaluations and protocol refinements are planned based on litter size and litter number in these colonies.


Subject(s)
Estrus Synchronization/physiology , Mice, Knockout/physiology , Mice, Transgenic/physiology , Pregnancy, Animal/physiology , Animals , Animals, Newborn , Female , Male , Mice , Pregnancy , Time Factors
5.
Brain Res ; 1123(1): 51-9, 2006 Dec 06.
Article in English | MEDLINE | ID: mdl-17045970

ABSTRACT

Mesencephalic dopamine neurons form synapses with acetylcholine (ACh)-containing interneurons in the nucleus accumbens (NAcc). Although their involvement in drug reward has not been systematically investigated, these large aspiny interneurons may serve an important integrative function. We previously found that repeated activation of nicotinic cholinergic receptors enhanced cocaine intake in rats but the role of muscarinic receptors in drug reward is less clear. Here we examined the impact of local changes in muscarinic receptor activation within the NAcc on cocaine and food self-administration in rats trained on a progressive ratio (PR) schedule of reinforcement. Animals were given a minimum of 9 continuous days of drug access before testing in order to establish a stable breaking point (BP) for intravenous cocaine infusions (0.75 mg/kg/infusion). Rats in the food group acquired stable responding on the PR schedule within 7 days. On the test day, rats were bilaterally infused in the NAcc with the muscarinic receptor agonist oxotremorine methiodide (OXO: 0.1, 0.3 or 1 nmol/side), OXO plus the M(1) selective antagonist pirenzepine (PIRENZ; 0.3 nmol/side) or aCSF 15 min before cocaine or food access. OXO dose dependently reduced BP values for cocaine reinforcement (-17%, -44% [p<0.05] and -91% [p<0.0001] for 0.1, 0.3 and 1.0 nmol, respectively) and these reductions dissipated by the following session. Pretreatment with PIRENZ blocked the BP-reducing effect of 0.3 nmol OXO. Notably, OXO (0.1, 0.3 and 1.0 nmol/side) injection in the NAcc did not affect BP for food reward. The results suggest that muscarinic ACh receptors in the caudomedial NAcc may play a role in mediating the behavior reinforcing effects of cocaine.


Subject(s)
Behavior, Addictive/metabolism , Feeding Behavior/drug effects , Muscarinic Agonists/administration & dosage , Nucleus Accumbens/metabolism , Oxotremorine/administration & dosage , Receptors, Muscarinic/metabolism , Analysis of Variance , Animals , Cocaine/administration & dosage , Cocaine-Related Disorders/metabolism , Dose-Response Relationship, Drug , Feeding Behavior/physiology , Male , Microinjections , Nucleus Accumbens/drug effects , Rats , Rats, Sprague-Dawley , Receptors, Muscarinic/drug effects , Reward , Self Administration
6.
Nat Neurosci ; 8(4): 413-4, 2005 Apr.
Article in English | MEDLINE | ID: mdl-15735642

ABSTRACT

Understanding the neurobiology of motivation might help in reducing compulsive behaviors such as drug addiction or eating disorders. This study shows that excitatory synaptic transmission was enhanced in the bed nucleus of the stria terminalis of rats that performed an operant task to obtain cocaine or palatable food. There was no effect when cocaine or food was delivered passively, suggesting that synaptic plasticity in this area is involved in reward-seeking behaviors.


Subject(s)
Cocaine/administration & dosage , Neuronal Plasticity/physiology , Neurons/drug effects , Septal Nuclei/cytology , Synaptic Transmission/physiology , Animals , Behavior, Animal/drug effects , Behavior, Animal/physiology , Conditioning, Operant/drug effects , Conditioning, Operant/physiology , Dopamine Uptake Inhibitors/administration & dosage , Excitatory Amino Acid Agonists/pharmacology , Excitatory Postsynaptic Potentials/drug effects , Excitatory Postsynaptic Potentials/physiology , Food Preferences/physiology , In Vitro Techniques , Male , N-Methylaspartate/pharmacology , Neuronal Plasticity/drug effects , Neurons/physiology , Patch-Clamp Techniques/methods , Rats , Rats, Sprague-Dawley , Reinforcement Schedule , Self Administration/methods , Septal Nuclei/drug effects , Synaptic Transmission/drug effects , alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid/pharmacology
SELECTION OF CITATIONS
SEARCH DETAIL
...