Role of preexisting inhibitory control deficits vs. drug use history in mediating insensitivity to aversive consequences in a rat model of polysubstance use.

Rationale: The nature and predictors of insensitivity to aversive consequences of heroin + cocaine polysubstance use are not well characterized.

Objectives: Translational methods incorporating a tightly controlled animal model of drug self-administration and measures of inhibitory control and avoidance behavior might be helpful for clarifying this issue.

Methods: The key approach for distinguishing potential contributions of pre-existing inhibitory control deficits vs.

Ovarian hormones control the changing expression of claudins and occludin in rat uterine epithelial cells during early pregnancy.

Regulation of the uterine luminal environment is important for successful attachment and implantation of the blastocyst. The contents and volume of luminal fluid are regulated in part by the tight junctions. Using immunofluorescence microscopy, protein and RNA analysis, the cellular distributions of tight junction components claudins and occludin were observed during early pregnancy and under various hormonal regimens.

An Actn3 knockout mouse provides mechanistic insights into the association between alpha-actinin-3 deficiency and human athletic performance.

A common nonsense polymorphism (R577X) in the ACTN3 gene results in complete deficiency of the fast skeletal muscle fiber protein alpha-actinin-3 in an estimated one billion humans worldwide. The XX null genotype is under-represented in elite sprint athletes, associated with reduced muscle strength and sprint performance in non-athletes, and is over-represented in endurance athletes, suggesting that alpha-actinin-3 deficiency increases muscle endurance at the cost of power generation. Here we report that muscle from Actn3 knockout mice displays reduced force generation, consistent with results from human association studies.