| pubmed-article:8085660 | pubmed:abstractText | The pinealocytes in male roseringed parakeets (Psittacula krameri) were studied following bilateral castration and/or therapeutic administration of testosterone during the preparatory (June-July), progressive (Nov.-Dec.), pre-breeding (Jan.-Feb.) and breeding (March-April) phases of the annual testicular cycle. The responses of the pineal to either treatment were found to be almost identical throughout the investigation. In each reproductive phase, the pineal appeared to be hypertrophied following castration and the effect was reversed by therapeutic administration of testosterone, while hormonal treatment to the intact parakeets induced regressive changes in the pinealocytes. Collectively, the results of the current study support the hypothesis that the testis through its hormone testosterone exerts inhibitory influences on the activity of pineal, and may thus be considered as being involved in the determination of an inverse relationship between the pineal and the testis during the annual cycle of free-living parakeets. | lld:pubmed |
