Defensive burying by mice: Intraspecific genetic variation and retention

Abstract

Genotypically based within-species differences in defensive burying were examined in 180 mice representing 15 inbred strains. Each mouse was tested twice in a cylindrical test chamber containing two similar prods. In the first test, one of the prods was electrified, whereas in the second test (24 h later), neither prod was. Although most strains selectively buried the shock prod in the first test (as determined by bedding-height-at-prod and position-of-highest-beddingpile criteria), some strains did not discriminate between the shock and dummy prods and still others displayed little prod-directed bedding displacement at all (thereby resembling a heterogeneous nonshocked control group). In general, burying tended to be somewhat reduced in the second test, but strain differences in retention were observed. Factors contributory to the observed differences among strains and the need for multiple measures of burying are discussed. Collectively, these findings indicate that intraspecific genetic variation, acting at multiple burying-relevant behavioral levels, can be an important determinant of the expression of the defensive-burying response in mice. 465The novel rodent behavior termed "defensive burying" by Pinel and Treit (1978) has been the focus of a considerable amount of research effort in the last few years. This behavior, first noted by Hudson (1950), is characterized by the persistent approach by some rodents to a localized, stationary source of aversive stimulation, and the covering of the source with materials found in the vicinity. A single exposure to the aversive stimulus is generally sufficient to initiate burying (Pinel, Treit, & Wilkie, 1980;Tarte & Oberdieck, 1982), and the behavior often continues despite additional exposures encountered in the process of burying (this lab). Two general types of procedure have been employed to study this behavior. One uses a single aversive stimulus, and comparisons are made with independent control groups. The other uses two stimuli differing to some extent in aversive, visual, spatial, or other properties. In this second situation, within-subject comparisons of behavior toward each stimulus are possible.Much 1983;Treit et al., 1980) compared only two genetically distinct groups. Although such small numbers of groups provide a very limited basis for assessing the influence of genetic differences on defensive burying, within-and/or between-species burying differences were demonstrated in each.Within-species strain comparisons of defensive burying have been reported only for rats (Rattus norvegicus) and mice (Mus museu/us). McKim and Lett (1979) found that Long-Evans hooded rats displayed more pres hock burying of a prod than did Sprague-Dawley albino rats. Tarte and Oberdieck (1982) found that Long-Evans hooded rats also spent more time burying a single shock rod than did Wistar albino rats, but only after habituation to the test chamber. Treit et al. (1980) reported, however, that in a two-prod situation Wistar rats spent more time burying than did Long-Evans r...

Marble burying and spontaneous motor activity in mice: interactions over days and the effect of diazepam

“…Rats and mice have been found to bury all manner of unpleasant articles including electrified (shock) or heated metal prods, discriminable food pellets associated with poisons, or even dead conspecifics. under the particular bedding material available (Harder & Maggio, 1983;Pinel & Treit, 1978;Wilkie el al.. 1979). Recently, however, an ingenious development on the defensive burying procedure was demonstrated by Broekkampetaf.…”

Behavioral field analysis in two strains of rats in a conditioned defensive burying paradigm

“…Predisposing factors have proven to be important in determining whether defensive burying occurs. Some studies have dealt with intraspecific (Harder & Maggio, 1983) or cross-specific variations This research was supported by a Grant-in-Aid for Encouragement of Young Scientists (60710097) to A. Tsuda from the Ministry ofEducation, Science and Culture of Japan. We would like to thank Gary B. Glavin of the Department of Pharmacology and Therapeutics, University of Manitoba, Winnipeg, Canada, for his kindreviewing of an earlier version of this manuscript.…”