Effects of neonatal castration and testosterone injection on adult open-field behaviour in rats with atypical sex difference in defecation.
In the open-field test, male rats usually defecate more and ambulate less than females. A strain was studied in which the males defecate less than females, while still ambulating less. Infants of this strain were castrated (males) or injected with testosterone propionate (females) and tested in the open field as adults. There were significant effects of these neonatal treatments on ambulation, but not on defecation, in contrast to previous reports for the latter measure in rats showing a sex difference in defecation taking the usual direction. It is suggested that absence of the usual direction of a sex difference normally under the developmental control of androgen may indicate a genotype which has escaped from such control. Finally, a number of 'sibling' effects' were observed, i.e. effects on the adult behaviour of the members of one sex in a litter produced by treatments administered in infancy to members of the other sex.
D000818:Animals; D000831:Animals, Newborn; D002369:Castration; D003672:Defecation; D005260:Female; D008124:Locomotion; D008297:Male; D051381:Rats / Q000502:physiology*; D012737:Sex Factors; D013737:Testis / Q000502:physiology*; D013739:Testosterone / Q000494:pharmacology*
D013739:Testosterone