Ectopic Brain Tissue in Laboratory Rats

Abstract

Ectopic brain tissue was detected in 11 days old rats. The anomaly was found medial and caudal of the scapula on the right chest wall appearing as a glandlike structure. Animals with ectopic brain tissue were found to have a lower relative brain
weight indicating a development error in which neuroectodermal cells had been ”pinched off” and displayed early in embryonic development. Several etiological possibilities are discussed, i.e. genetic background, virusinfections, chemicals, toxins
and environmental factors. A correlation between a situation with the parameters of high temperature and low humidity versus an increased frequency of the anomaly seemed possible. As the microbiological status of the animals, food quality and most environmental factors were not known it was stated, however, that the patogenesis of the ectopic brain tissue is still unknown.