Postnatal Development of Brain and Behavior of Shaker Short-Tail Mice

UNCG Author/Contributor (non-UNCG co-authors, if there are any, appear on document)
Douglas Wahlsten, Visiting Professor (Creator)
Institution
The University of North Carolina at Greensboro (UNCG )
Web Site: http://library.uncg.edu/

Abstract: Effects of the shaker short-tail gene (an allele at the dreher locus) on behavior and brain morphology were studied. A total of 20 separate litters was tested, one each day from birth to 20 days and one every other day from 22 to 30 days. Within a litter, all homozygous mutant mice (drsst/ drsst) and one normal sibling ( + / - ) were examined. A larger sample of mutant mice and their siblings from seven litters was observed 10 days after birth. The homozygous recessive genotype (drsst/ drsst) resulted in retardation of the overall growth of the body and brain, but genetic effects on the tail and cerebellum, which were highly variable and uncorrelated, could not be attributed solely to a general retardation of development. Performance on a standard battery of reflex tests was also severely retarded in mutant mice, especially the righting reflex and cliff aversion response. When frequencies of 36 behavior patterns during 5 min in a simple environment were compared, immature behavior patterns such as pivoting disappeared from the repertoire of mutant mice but normal patterns of locomotion were never achieved. Instead of walking in a straight path, the animals often circled or walked while swaying from side to side. Older mutants were almost always active. When the four paws were motionless on the ground, the head was usually shaking or tossing. Only grooming behavior appeared to be relatively normal. The degree of defect in motor behaviors was positively correlated with the degree of abnormality in the cerebellum, which in some cases was almost absent.

Additional Information

Publication
Behavior Genetics, 1988, 18, 35-53.
Language: English
Date: 1988
Keywords
Dreher, Brain weight, Cerebellum, Reflex ontogeny, Developmental rate, Behavioral repertoire