Distinct dynamics of social motivation drive differential social behavior in laboratory rat and mouse strains

Mice and rats are widely used to explore mechanisms of mammalian social behavior in health and disease, raising the question whether they actually differ in their social behavior. Here we address this question by directly comparing social investigation behavior between two mouse and rat strains used most frequently for behavioral studies and as models of neuropathological conditions: C57BL/6 J mice and Sprague Dawley (SD) rats. Employing novel experimental systems for behavioral analysis of both subjects and stimuli during the social preference test, we reveal marked differences in behavioral dynamics between the strains, suggesting stronger and faster induction of social motivation in SD rats. These different behavioral patterns, which correlate with distinctive c-Fos expression in social motivation-related brain areas, are modified by competition with non-social rewarding stimuli, in a strain-specific manner. Thus, these two strains differ in their social behavior, which should be taken into consideration when selecting an appropriate model organism

Cardiovascular complications of pregnancy-associated COVID-19 infections

Cardiovascular complications are frequently present in coronavirus-2019 (COVID-19) infection. These include microvascular and macrovascular thrombotic complications such as arterial and venous thromboembolism, myocardial injury or inflammation resulting in infarction, heart failure, and arrhythmias. Data suggest increased risk of adverse outcomes in pregnant compared with nonpregnant women of reproductive age with COVID-19 infection, including need for intensive care unit admission, mechanical ventilation, and extracorporeal membrane oxygenation utilization. Current statements addressing COVID-19-associated cardiac complications do not include pregnancy complications that may mimic COVID-19 complications such as peripartum cardiomyopathy, spontaneous coronary artery dissection, and preeclampsia. Unique to pregnancy, COVID-19 complications can result in preterm delivery and modify management of the pregnancy. Moreover, pregnancy has often been an exclusion criterion for enrollment in research studies. In this review, we summarize what is known about pregnancy-associated COVID-19 cardiovascular complications