title: Intrathecal cocaine delivery enables long-access self-administration with binge-like behavior in mice.
abstract: BACKGROUND
  Long-access intravenous drug self-administration shows diurnal alterations in drug intake, with escalation and binge patterns, in rats. A similar long-access model in mice would allow the use of genetically modified animals to better understand the molecular mechanisms underlying drug addiction and relapse. However, attempts to transfer this model to mice have been less successful, mainly because of technical difficulties with long-term maintenance of the indwelling catheter implanted into small veins.
  
  
  OBJECTIVE
  We devised an intrathecal probe implanted in the supracerebellar cistern as an alternative for intravenous drug administration to address this challenge and allow continuous, chronic drug self-administration in mice.
  
  
  RESULTS
  We found that mice readily self-administered intrathecal infusions of cocaine as a drug reward, and, under daily 24-h access conditions, animals exhibited a binge-like behavior comparable to rats.
  
  
  CONCLUSIONS
  This innovation enables a full analysis of long-access drug self-administration behavior in mice not possible with intravenous administration.
authors.affiliation: Department of Psychology and Behavioral Neuroscience, Hamamatsu University School of Medicine, 1-20-1 Handayama, Higashi-ku, Hamamatsu, Japan.
authors.forename: Masato
authors.initials: M
authors.lastname: Nakamura
authors.forename: Shuibo
authors.initials: S
authors.lastname: Gao
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Okamura
authors.forename: Daiichiro
authors.initials: D
authors.lastname: Nakahara
mesh_terms: D000818:Animals; D016739:Behavior, Addictive / Q000139:chemically induced*; D002940:Circadian Rhythm / Q000187:drug effects; D003042:Cocaine / Q000008:administration & dosage* / Q000494:pharmacology*; D019970:Cocaine-Related Disorders / Q000523:psychology; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D007278:Injections, Spinal; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D012646:Self Administration; D015819:Substance Abuse, Intravenous / Q000523:psychology
chemical_list: D003042:Cocaine