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.
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.
Valentinuzzi
V S
VS
Center for Circadian Biology and Medicine, Department of Neurobiology and Physiology, Northwestern University, Evanston, Illinois 60208, USA.
Kolker
D E
DE
Vitaterna
M H
MH
Shimomura
K
K
Whiteley
A
A
Low-Zeddies
S
S
Turek
F W
FW
Ferrari
E A
EA
Paylor
R
R
Takahashi
J S
JS
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
D005819:Genetic Markers