Effects of apomorphine on mating behavior, flank marking and aggression in male hamsters

In male rats, the dopamine agonist apomorphine (APO) generally facilitates copulatory behavior. However, disruptive effects of high APO doses have been reported. These have been interpreted in diverse ways, as products of a dopaminergic system that inhibits sexual behavior or as consequences of APO's stimulation of competing responses. To test the generality of these effects, we observed APO's impact on copulatory behavior in male hamsters. Several effects were observed, all attributable to a relatively high dose and involving the disruption of male behavior. More unexpectedly, APO treatment caused males to attack estrous stimulus females in the course of these tests. To clarify these effects, we observed the effects of APO on flank marking, a type of scent marking closely allied to aggression and dominance in hamsters. Treatment reliably decreased the latency of marking. It also increased the rate of marking when appropriate measures were taken to prevent this effect from being obscured by drug-induced cheek pouching. Together, these results confirm and extend APO's well-known ability to increase aggression. Further, they suggest that APO-induced aggression can intrude into other contexts so as to disrupt, or possibly facilitate, other forms of social behavior.

The Financial Rate of Profit: What Is It, and How Has It Behaved in the United States?

This work contributes to the almost nonexistent literature on the profit rate of the financial sector. It updates the single study to include financial variables to cover the past decade, compares this profit rate to the (almost unpublished) Weisskopf and NIPA financial profit rates, compares the financial and nonfinancial sector rates, and details the procedure to construct the profit rate in the financial sector including relevant financial variables which capitalists consider to make profit-rate decisions. JEL Classification: B50, E11