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 intercross

VALENTINUZZI VS ; KOLKER DE; VITATERNA MH; SHIMOMURA EK; WHITELEY A; LOW-ZEDDIES S; TUREK FW; FERRARI EAM; PAYLOR R; TAKAHASHI JS

LEARNING & MEMORY (COLD SPRING HARBOR, N.Y.)

Cold Spring Harbor Laboratory Press

Lugar: New York; Año: 1998 vol. 5 p. 391 - 403

1072-0502

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 × 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.