Differential responses to serotonin receptor ligands in an impulsive-aggressive phenotype.
Offensive aggression in golden hamsters is inhibited by 5-hydroxytryptamine (5-HT)1A receptors and facilitated by 5-HT3 receptor activation. As such, we sought to determine whether these receptors function similarly between animals expressing an impulsive-aggressive phenotype, as compared to normal animals. Animals were screened for aggressive and impulsive choice behaviors and categorized into Low-Aggression (L-Agg) and High-Aggression (H-Agg) groups, and then tested for behavior under effective doses of 5-HT1A receptor agonist 8-hydroxy-N, N-dipropyl-2-aminotetralin (DPAT; 0.1 mg/kg and 0.3 mg/kg) or 5-HT3 receptor antagonist tropisetron (0.3 mg/kg) treatment. Low-dose DPAT treatment inhibited both behaviors in H-Agg animals, however yielding more modest effects in L-Agg animals; while high-dose DPAT effects were confounded by side effects on locomotion. Tropisetron, on the other hand, had differential effects between groups, as aggression and impulsive choice were both inhibited in H-Agg animals, while enhanced in L-Agg individuals. In addition, while the effects of the 5-HT1A receptor were limited, the broad effects of 5-HT3 receptor included repetitive and impulsive elements of behavior, pointing to the importance of the receptor's role in the modulation of these particular aspects within the phenotype.
Cervantes
M Catalina
MC
Institute for Neuroscience, University of Texas at Austin, USA. catalinacervantes@mail.utexas.edu
Biggs
Emily A
EA
Delville
Yvon
Y
D017371:8-Hydroxy-2-(di-n-propylamino)tetralin / Q000494:pharmacology; D000374:Aggression / Q000187:drug effects*; D000704:Analysis of Variance; D000818:Animals; D000831:Animals, Newborn; D001522:Behavior, Animal; D002755:Choice Behavior / Q000187:drug effects / Q000502:physiology; D006224:Cricetinae; D007175:Impulsive Behavior / Q000188:drug therapy*; D007211:Indoles / Q000494:pharmacology; D008024:Ligands; D008297:Male; D008647:Mesocricetus; D009043:Motor Activity / Q000187:drug effects; D010641:Phenotype; D011930:Reaction Time / Q000187:drug effects; D018490:Serotonin Agents / Q000494:pharmacology*; D000077526:Tropisetron
D007211:Indoles; D008024:Ligands; D018490:Serotonin Agents; D000077526:Tropisetron; D017371:8-Hydroxy-2-(di-n-propylamino)tetralin