Reciprocal changes in corticosterone and testosterone levels following acute and chronic handling stress in the tree lizard, Urosaurus ornatus
To examine the reciprocal interactions among gonadal and adrenal steroid secretion, male tree lizards (Urosaurus ornatus) were subjected to two forms of stress. They were subjected either to the acute stress of being held in collecting bags for up to 4 hr or to the chronic stress of being maintained in individual cages in the […]
Effects of short postcapture confinement on plasma reproductive hormone and corticosterone profiles in Rana esculenta during the sexual cycle
The effects of short-term confinement (24 hours) on the plasma levels of gonadal hormones and corticosterone have been evaluated in Rana esculenta, which is widely used in amphibian reproductive physiology studies. A 24-h confinement has been chosen since this is the time that usually elapses from frog capture to utilization. Although short confinement does not […]
Activity pattern, reproductive behaviors and gonadal hormones in the raccoon dog (Nyctereutes procyonoides)
Abstract The objectives of this study were to (1) assess year-round behaviors and activity patterns of captive raccoon dogs (Nyctereutes procyonoides) and (2) characterize the species’ reproductive endocrinology. Behaviors and activity patterns of 12 (5.7) animals were recorded over a 1-year period. During that time, fecal samples were collected 2–7 times/week from 16 (7.9) individuals […]
Organizational effects of estrogen on male-type vulnerability to early weaning
Abstract We previously reported that early-weaned (postnatal day 14) male ICR mice, compared to normally weaned animals, exhibited a persistent increase in anxiety-related behavior in the elevated plus maze test. In this study, we examined whether steroid hormone manipulations on postnatal day 0 and at the ages of 2 or 3 weeks affected male-type vulnerability […]
Testosterone inhibits facilitating effects of parenting experience on parental behavior and the oxytocin neural system in mice
Abstract Parental behavior in mammals is facilitated by sensory experiences from infant, and by endocrine hormones. However, the interactions between these factors in the parental behavior of nonreproductive adults are not understood. We examined the interactive effects of gonadal hormones and the experience of repeated pup exposure on parental behavior in sexually naive mice. We […]