Enhanced Aggressive Behavior in Mice Lacking 5-HT _1B Receptor

TLDR

Serotonin (5‑hydroxytryptamine, 5‑HT) is linked to mood disorders such as depression, anxiety, and impulsive violence. The study aimed to define the contribution of 5‑HT receptor subtypes to behavior. Mutant mice lacking the 5‑HT 1B receptor were generated by homologous recombination. The 5‑HT 1B receptor knockout mice showed no developmental or behavioral defects, lacked the hyperlocomotor response to the 5‑HT 1A/1B agonist RU24969, and displayed faster and more intense attacks toward intruders, indicating a role for 5‑HT 1B receptors in aggressive behavior.

Abstract

The neuromodulator serotonin (5-hydroxytryptamine, 5-HT) has been associated with mood disorders such as depression, anxiety, and impulsive violence. To define the contribution of 5-HT receptor subtypes to behavior, mutant mice lacking the 5-HT 1B receptor were generated by homologous recombination. These mice did not exhibit any obvious developmental or behavioral defects. However, the hyperlocomotor effect of the 5-HT 1A/1B agonist RU24969 was absent in mutant mice, indicating that this effect is mediated by 5-HT 1B receptors. Moreover, when confronted with an intruder, mutant mice attacked the intruder faster and more intensely than did wild-type mice, suggesting the participation of 5-HT 1B receptors in aggressive behavior.