title: Absence of 5-HT(1B) receptors is associated with impaired impulse control in male 5-HT(1B) knockout mice.
abstract: BACKGROUND
  Serotonin (5-HT) plays a complex regulatory role in processes like anxiety, depression, aggression, and impulse control. Due to the large amount of serotonergic receptors, knockout mice offer an important opportunity to investigate the role of specific receptors. The 5-HT(1B) receptor is thought to mediate aggression and impulse control. This was studied here in mice lacking 5-HT(1B) receptors (5-HT(1B) KO).
  
  
  METHODS
  Wild type and 5-HT(1B) KO mice were exposed to several types of entrained and nonentrained stimuli. With telemetry, body temperature, heart rate, and locomotor activity were measured continuously during the different experiments.
  
  
  RESULTS
  To nonentrained stimuli like disturbance stress and confrontation with an intruder, 5-HT(1B) KO mice showed exaggerated physiologic and behavioral responses. These mice displayed behavioral disinhibition, measured as increased social interest and aggression to an intruder mouse. However, in response to well-entrained stimuli like daily light transitions, responses were smaller in 5-HT(1B) KO than in wild type mice, suggesting that hyperreactivity is stimulus specific.
  
  
  CONCLUSIONS
  Serotonin 1B receptors are essential in impulse control by inhibiting responses to nonentrained stimuli. Therefore, the 5-HT(1B) KO mouse might be an important additional model for studying aspects of disinhibition in aggression and impulse control.
authors: Department of Psychopharmacology, Faculty of Pharmacy, Utrecht University, Utrecht, The Netherlands.
authors: J A
authors: JA
authors: Bouwknecht
authors: T H
authors: TH
authors: Hijzen
authors: J
authors: J
authors: van der Gugten
authors: R A
authors: RA
authors: Maes
authors: R
authors: R
authors: Hen
authors: B
authors: B
authors: Olivier
mesh_terms: D000374:Aggression / Q000502:physiology*; D000818:Animals; D001831:Body Temperature; D002940:Circadian Rhythm; D004195:Disease Models, Animal; D006339:Heart Rate; D007175:Impulsive Behavior / Q000235:genetics*; D007266:Inhibition, Psychological; D008297:Male; D051379:Mice; D018345:Mice, Knockout; D009043:Motor Activity; D044302:Receptor, Serotonin, 5-HT1B; D011985:Receptors, Serotonin / Q000172:deficiency / Q000378:metabolism / Q000502:physiology*
chemical_list: D044302:Receptor, Serotonin, 5-HT1B; D011985:Receptors, Serotonin