Holly et al. examined the effects of cocaine in male and female rats after social defeat. In experiment 1, I would have liked to see data presented from more than just 5-10 minutes and 25-30 minutes. I think it would have been more interesting to see when the differences in walk duration occurred across the entire experiment. Also, statistical significance markers seemed confusing and crowded in the figure. It might have looked cleaner if they broke it up into multiple figures. In experiment 2, when tonic dopamine was being analyzed, estrous and non-estrous females weren’t separated. I think that separating the females by estrous cycle would strengthen the data because they talked about how their research is important because not much work has been done in the past about cocaine addiction and circulating levels of estradiol in females.
In the discussion, the authors addressed that the social defeat paradigm in males is different than females because of the body locations that the aggressors attacked. They said that there was no difference in stress response. However, I was wondering if the differences in cocaine response were due to the differences in social defeat. In the future, it would be interesting for another set of experiments like these to be done with a different stressor to see if the differences in response to cocaine were from the differences in social defeat stress.
Vassoler et al. examined the effects of paternal cocaine self-administration on offspring. The day following 60 days of cocaine use, rat fathers mated with females. The researchers investigated the differences in cocaine-sired male and female offspring’s response to cocaine. In the discussion, the authors mention that circulating gonadal hormones, including estrogen, may play a role in the differences. The Holly et al. paper showed that higher levels of estradiol enhance the effects of cocaine, so some of the sex differences found in this experiment may be because of that.
Also, it would be interesting to see what effects paternal cocaine use would have if the fathers had been abstinent from cocaine use for a period of time before mating. This would show if the harmful effects of cocaine on paternal sperm are chronic or acute.