Effect of Continuous Trio Breeding Compared with Continuous Pair Breeding in 'Shoebox' Caging on Measures of Reproductive Performance in Estrogen Receptor Knockout Mice.

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.

Peroxisomal biogenesis in ischemic brain.

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.

Therapy with recombinant T-cell receptor ligand reduces infarct size and infiltrating inflammatory cells in brain after middle cerebral artery occlusion in mice.

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).

Refining timed pregnancies in two strains of genetically engineered mice.

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.

Injection of oxotremorine in nucleus accumbens shell reduces cocaine but not food self-administration in rats.

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.

Self-administration enhances excitatory synaptic transmission in the bed nucleus of the stria terminalis.

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.