title: Automated measurement of mouse freezing behavior and its use for quantitative trait locus analysis of contextual fear conditioning in (BALB/cJ x C57BL/6J)F2 mice.
abstract: The most commonly measured mouse behavior in fear conditioning tests is freezing. A technical limitation, particularly for genetic studies, is the method of direct observation used for quantifying this response, with the potential for bias or inconsistencies. We report the use of a computerized method based on latency between photobeam interruption measures as a reliable scoring criterion in mice. The different computer measures obtained during contextual fear conditioning tests showed high correlations with hand-scored freezing; r values ranged from 0.87 to 0.94. Previously reported strain differences between C57BL/6J and DBA/2J in context-dependent fear conditioning were also detected by the computer-based system. In addition, the use of computer-scored freezing of 199 (BALB/cJ x C57BL/6J)F2 mice enabled us to detect a suggestive gender-dependent chromosomal locus for contextual fear conditioning on distal chromosome 8 by QTL analysis. Automation of freeze scoring would significantly increase efficiency and reliability of this learning and memory test.
authors.affiliation: Center for Circadian Biology and Medicine, Department of Neurobiology and Physiology, Northwestern University, Evanston, Illinois 60208, USA.
authors.forename: V S
authors.initials: VS
authors.lastname: Valentinuzzi
authors.forename: D E
authors.initials: DE
authors.lastname: Kolker
authors.forename: M H
authors.initials: MH
authors.lastname: Vitaterna
authors.forename: K
authors.initials: K
authors.lastname: Shimomura
authors.forename: A
authors.initials: A
authors.lastname: Whiteley
authors.forename: S
authors.initials: S
authors.lastname: Low-Zeddies
authors.forename: F W
authors.initials: FW
authors.lastname: Turek
authors.forename: E A
authors.initials: EA
authors.lastname: Ferrari
authors.forename: R
authors.initials: R
authors.lastname: Paylor
authors.forename: J S
authors.initials: JS
authors.lastname: Takahashi
mesh_terms: D000818:Animals; D001331:Automation / Q000379:methods; D001362:Avoidance Learning / Q000502:physiology*; D002874:Chromosome Mapping; D003433:Crosses, Genetic; D004597:Electroshock; D005239:Fear; D005260:Female; D005819:Genetic Markers; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D009043:Motor Activity; D019655:Quantitative Trait, Heritable; D011930:Reaction Time; D012727:Sex Characteristics; D012984:Software
chemical_list: D005819:Genetic Markers