Differences in fear motivated behaviors among inbred mouse strains

Abstract

The behavioral performance of inbred mouse strains was examined in animal models of anxiety to evaluate the potential contribution of genetic factors to fear-motivated behaviors. The preference that randomly bred mice and rats exhibit for the enclosed as opposed to the open arms of an elevated maze has been considered a fear-motivated behavior. Pronounced differences were observed in this measure among 16 inbred mouse strains. An estimate of the proportion of the variance attributable to between-strain differences, eta 2, revealed that 78% and 69% of the variance in time and number of entries in the open arms of an elevated maze, respectively, can be attributed to genetic factors. In contrast, only 27% and 42% of the variance could be attributed to between-strain differences in ambulatory activity in the open field and elevated maze, respectively. Furthermore, performance in the elevated maze was predictive of behavior in other animal models of anxiety. Thus, significant negative correlations were observed among inbred mouse strains between the percent time spent in the open arms of the elevated maze and amplitude of an acoustic startle response (rs = -0.88m P < 0.01) or latency to initiate chow consumption in a hyponeophagia paradigm (rs = -0.71, P < 0.05). These results indicate that genetic factors substantially contribute to fear motivated behaviors in these animal models of anxiety. The use of such inbred mouse strains may provide a novel approach to investigate the biochemical and genetic bases of fear.

QTL Analysis of Multiple Behavioral Measures of Anxiety in Mice

“…It is generally assumed that the various tests of anxiety in rodents, such as the elevated plus maze, open-field arena, and conditioned fear paradigms, measure at least one common underlying trait. Consistent with this hypothesis, Trullas and Skolnick (1993) report that performance in the elevated maze predicts behavior in other animal models of anxiety. In a study comparing inbred mouse strains, they found significant negative correlations between the time spent in the open arms of the elevated maze and amplitude of an acoustic startle or latency to eat in a hyponeophagia test.…”

“…When inbred strain means replace individual subject observations, (e.g., Collins et al, 1988, Henderson, 1979Ramos and Mormede, 1998;Trullas and Skolnick, 1993) the influence of test session and environmental history V-C matrices are reduced by a factor of (n per strain) −1 , effectively creating a genotypic correlation matrix when n is even moderately large. Factor analyses of genotypic correlation matrices thus avoid the confounding influences of test session environmental effects.…”

Voluntary ethanol consumption in 22 inbred mouse strains

“…Since the MPD variables reflect data in alcohol naive strains, the genetic relationship between alcohol consumption and measures of activity and anxiety may reflect the strain differences in locomotor activity and anxiety that exist (e.g., Finn et al, 2003;Trullas and Skolnick, 1993;Wahlsten et al, 2003). With regard to bone mineral density, limited evidence suggests that there is no consistent relationship between high bone mass or strength with selection for high alcohol consumption and/or preference in rat lines (Alam et al, 2005), whereas data from animal models of chronic or excessive alcohol intake suggest that chronic exposure to high alcohol doses can inhibit bone formation (e.g., Wahl et al, 2006).…”

Behavioral profile of wild mice in the elevated plus-maze test for anxiety

“…In an extensive comparison of inbred laboratory mouse strains, Trullas and Skolnick [61] characterized elevated plus-maze behavior on the basis of levels of open arm exploration. Thus, strains exhibiting low levels of open arm activity (e.g., A/J) were described as``high reactive'', while those showing high levels of activity in the open arms (e.g., C3H substrains, BALB/c substrains) were labeled``low reactive.''…”