Prediction of individual vulnerability to stress-induced gastric ulcerations in rats: a factor analysis of selected behavioral and biological indices.
Fifty rats were subjected seriatim to 6 different test tasks (open-field, startle, drug-induced sterotypy, oral finickiness, defensive burying, and memory for aversive event). This yielded 12 test-specific plus 2 general biobehavioral measures (growth and defecation). These 14 measures were subjected to factor analysis to determine if these measured tapped a common construct of "emotionality." The data yielded a 4-factor structure of Finickiness, Defensiveness, Startle-Sensitivity, and Dopaminergic-Sensitivity that accounted for 62% of the variance. Then, all rats were subjected to restraint-in-water stress to induce gastric ulcerations. Multivariate techniques tested if there was a factor or factor-structure that could predict individual differences in vulnerability to the stress-induced gastric ulcerations. Only the Dopaminergic-Sensitivity factor predicted ulcerogenic vulnerability, and its predictive power resided substantially in the latency to initiate stereotypic gnawing induced by apomorphine. This single test score correlated with amount of ulcer (r = +0.52), accounting for 25% of the variance in ulcer, suggesting that 1. prescreening rats on this variable could be a tool for reducing intrastrain experimental variance in future studies of treatments that modulate ulcerogenicity, and 2. the dopaminergic system may be intimately involved in the causal path of ulcerogenicity.
Overmier
J B
JB
Faculty of Psychology, University of Bergen, Norway. psyjbo@vx.cis.umn.edu
Murison
R
R
Johnsen
T B
TB
D000818:Animals; D005163:Factor Analysis, Statistical; D008297:Male; D010437:Peptic Ulcer / Q000503:physiopathology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013315:Stress, Psychological / Q000503:physiopathology*