title: A novel semi-automated apparatus for measurement of aggressive biting behavior in mice.
abstract: BACKGROUND
  Currently, behavioral research of aggressiveness is often conducted with intraspecific intermale aggression tests. Intraspecific aggression is not detectable in early stages of psychiatric disorders or in female animals, except during the nursing period.
  
  
  METHODS
  We developed a semi-automated apparatus (ARM: Aggression Response Meter) for measurement of aggressive biting behavior (ABB) in mice. The apparatus is loaded with computer-controlled sticks that stimulate the mouse through touch, inducing irritation and anger. When the mouse bites the sticks in anger, a load sensor attached to the sticks detects ABB dynamically. Changes in ABB were assessed with isolation-reared/re-socialized mice using the ARM, and additional isolation-reared mice were tested using both the ARM and the resident-intruder test, and then buspirone, a serotonin 1A receptor agonist, was administered.
  
  
  RESULTS
  ABB significantly increased during isolation rearing, and then significantly decreased throughout the re-socialization period; both changes were time-dependent. The ARM also detected ABB of female mice after 3 weeks of isolation rearing. Buspirone significantly inhibited aggressive behavior in both tests in a similar manner.
  
  
  CONCLUSIONS
  The ARM detects aggressiveness in psychiatric disorders at an earlier stage and in both male and female mice.
  
  
  CONCLUSIONS
  ABB toward inanimate objects is a reliable paradigm that makes it possible to detect aggressiveness in the early stage of psychiatric disorders. The ARM is useful for the quantification of aggressiveness using the same individual repeatedly, and for objective evaluation of the effects of drugs on aggressiveness. The ARM can be used with both male and female mice.
authors.affiliation: Department of Neuroanatomy, Field of Neurology, Graduate School of Medical and Dental Sciences, Kagoshima University, 8-35-1 Sakuragaoka, Kagoshima 890-8544, Japan. Electronic address: s-kuchi@m.kufm.kagoshima-u.ac.jp.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Kuchiiwa
authors.affiliation: Department of Neuroanatomy, Field of Neurology, Graduate School of Medical and Dental Sciences, Kagoshima University, 8-35-1 Sakuragaoka, Kagoshima 890-8544, Japan; Department of Clinical Psychology, Graduate School of Human Science, Kagoshima Immaculate Heart University, 2365 Amatatsu-Cho, Satsuma-Sendai, 895-0011, Japan. Electronic address: toshiko@jundai.k-junshin.ac.jp.
authors.forename: Toshiko
authors.initials: T
authors.lastname: Kuchiiwa
mesh_terms: D000374:Aggression / Q000187:drug effects / Q000502:physiology* / Q000523:psychology; D000818:Animals; D014151:Anti-Anxiety Agents / Q000494:pharmacology; D001522:Behavior, Animal / Q000502:physiology; D002065:Buspirone / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D001330:Electronic Data Processing / Q000295:instrumentation / Q000379:methods*; D005260:Female; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D012934:Social Isolation / Q000523:psychology; D013997:Time Factors
chemical_list: D014151:Anti-Anxiety Agents; D002065:Buspirone
keywords: Aggressiveness; Anger responses toward inanimate objects; Drug evaluations; Effects of psychotropic agents; Female; Isolation-reared mice