Behavioral profile of L–741,741, a selective D4 dopamine receptor antagonist, in social encounters between male mice

Abstract

Although the role of dopamine D1-D2-D3 receptors in the modulation of aggression has been extensively documented, there is not information with respect to the implication of D4 receptor. The aim of this study was to examine the acute effects of L-741,741 (0.75, 1.5 and 3 mg/kg, i.p), a selective D4 receptor antagonist, on social encounters between male mice using an ethopharmacological approach. Ten min of diadic interactions were staged between a singly housed and an anosmic mouse in a neutral area. These encounters were videotaped and the accumulated time allocated by subjects to ten broad behavioral categories was estimated. Besides other behaviors, the aggressive and motor behaviors were evaluated 30 min after injection using an ethologically based analysis. L-741,741 did not affect significantly offensive behaviors (threat and attack), as compared with the control group. Likewise, motor and anxiety-related behaviors (such as social investigation, avoidance/flee or defense submission) were not altered after drug administration. These results suggest that dopamine D4 receptor is not involved in the modulation of aggressive behavior. Aggr. Behav. 29:552-557,

An ethopharmacological assessment of agmatine's effects on agonistic encounters between male mice

“…The present experiment was designed to examine the effects of a wide dose range of agmatine (2.5-80 mg/ kg, ip) on male mice in the isolation-induced aggression model. Although there are other animal models of aggression [Miczek et al, 2002], the ''isolation-induced aggression model'' has been extensively used to analyze the effects of numerous compounds on aggressive behaviour in mice [Brain et al, 1989;Manzaneque and Navarro, 1999;Martı´n-Lo´pez and Navarro, 2002;Navarro et al, 2003;Navarro and Maldonado, 2004].…”