Does exercise training preserve ischemic preconditioning in aged rat hearts by restoring the myocardial polyamine pool?
Exercise appears to restore preconditioning protection in aged rat hearts, possibly due to an increase in intracellular polyamines and an improvement in mitochondrial function in response to a preconditioning stimulus.
Repeated exposure to nicotine during adolescence had opposite effects on Pavlovian approach behavior in male and female rats but enhanced acquisition of a new response with conditioned reinforcement. Novel information on how nicotine exposure influences reward-related learning during adolescence may increase our understanding of neurobiological mechanisms involved in the initiation of smoking behavior.