Ethoexperimental techniques were applied to reassess sex steroid influences on social encounters in laboratory rodents. Parallel investigations on Lister Hooded rats and TO strain albino mice were completed, with treatments being applied to individually-housed rodents. Same-sex rats and mice were paired in combinations here a) both members were surgically-manipulated/injected with active material, b) both rodents were sham-operated/injected with control solutions or c) the subjects were treated differently. All three kinds of pairing were videotaped (60 and 10 minutes for rats and mice, respectively). Paired rats inhabited a large partitioned cage for 24 hr before the encounter whereas some mice were transferred to their partner's cage immediately before testing. Tapes were analysed by assessing the times allocated to broad behavioural categories of non-social investigation, social investigation, offense, defence, sexual activities (including genital sniffing) and immobility. The effects of castration of males (10 to 20 days previously) and ovariectomy combined with testosterone propionate treatment of female were studied. Intact males were treated for 4 or 8 days with progesterone (25mg/kg for both rats and mice), the anti-androgen cyproterone acetate (25 and 50 mg/kg for rats and mice) and the anti-oestrogen tamoxifen (500 and 1000 μ for rats and 50 and 100 μ for mice). Accessory gland weights were obtained to confirm treatment effectiveness. Similar data were obtained for rats and mice with complex treatment effects on social encounters. Offense <i>and</i> sexual behaviour were reduced by castration whereas immobility increased. Testosterone treatment of ovariectomized females generated offense. Progesterone reduced offense but increased immobility. Cyproterone acetate reduced offense and sexual behaviour. Tamoxifen mainly reduced offense. Significant changes in defence always seemed consequences of attack to which animals were subjected. Immobility could not be simply regarded as passive defence. Organ weight changes generally confirmed treatment effectiveness. Such tests are valuable for revealing complexities of drug/hormone actions but the data was often similar to that obtained from 'standard opponent' tests.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:637237 |
| Date | January 1987 |
| Creators | Hasan, S. A. |
| Publisher | Swansea University |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
Page generated in 0.0016 seconds