Estrogen receptor-alpha in the bed nucleus of the stria terminalis regulates social affiliation in male prairie voles (Microtus ochrogaster).

Estrogen receptor alpha (ERalpha) typically masculinizes male behavior, while low levels of ERalpha in the medial amygdala (MeA) and the bed nucleus of the stria terminalis (BST) are associated with high levels of male prosocial behavior. In the males of the highly social prairie vole (Microtus ochrogaster), increasing ERalpha in the MeA inhibited the expression of spontaneous alloparental behavior and produced a preference for novel females. To test for the effects of increased ERalpha in the BST, a viral vector was used to enhance ERalpha expression in the BST of adult male prairie voles.

Sex steroids are necessary in the second postnatal week for the expression of male alloparental behavior in prairie voles (Microtus ochragaster).

Sex steroids play a significant role in organizing male social behavior, which is associated with low levels of pro-social behavior and high levels of aggression. However, the role of steroids in organizing behavior in highly social males is unclear. The authors tested the hypothesis that low levels of sex steroids facilitate the expression of pro-social behavior in male prairie voles (Microtus ochragaster), predicting that inhibition of testosterone and estradiol would reduce spontaneous-alloparental behavior.

Photoperiod alters central distribution of estrogen receptor alpha in brain regions that regulate aggression.

Testosterone or its metabolite, estrogen, regulates aggression in males of many mammalian species. Because plasma testosterone levels are typically positively correlated with both aggression and reproduction, aggression is expected to be higher when males are in reproductive condition. However, in some photoperiodic species such as Siberian hamsters (Phodopus sungorus), males are significantly more aggressive in short day lengths when the testes are regressed and circulating testosterone concentrations are reduced.

The organizational effects of oxytocin on the central expression of estrogen receptor alpha and oxytocin in adulthood.

Background: Previous studies have demonstrated that neonatal manipulation of oxytocin (OT) has effects on the expression of estrogen receptor alpha (ER alpha) and the central production of oxytocin observed in juveniles (at weaning, 21 days of age). The goal of this study was to determine whether the effects of neonatal manipulation of OT last into adulthood, and if the effects differ from those observed during the early postnatal period. On the first day of life, prairie voles (Microtus ochrogaster) received one of three doses of OT (High, 3 microg; Med, 0.

Early experience affects the traits of monogamy in a sexually dimorphic manner.

The goal of this study was to examine the effects of early life experiences on the subsequent expression of traits characteristic of social monogamy in prairie voles (Microtus ochrogaster). During cage changes parents and their offspring were either transferred between cages in a cup (zero manipulation, MAN0) or with a gloved hand (one manipulation, MAN1). Following weaning the offspring were tested for alloparental behavior.

Oxytocin: behavioral associations and potential as a salivary biomarker.

Oxytocin (OT) is a neuropeptide that is produced primarily in the hypothalamus and is best known for its role in mammalian birth and lactation. Recent evidence also implicates OT in social behaviors, including parental behavior, the formation of social bonds, and the management of stressful experiences. OT is reactive to stressors, and plays a role in the regulation of both the central and autonomic nervous system, including effects on immune and cardiovascular function.

Effects of stress on parental care are sexually dimorphic in prairie voles.

The effects of stress on parental care are poorly understood, especially in biparental species where males also display care. Data from previous studies in prairie voles, as well as parallels with pair-bonding behavior, suggest the hypothesis that a stressful experience might facilitate parental care in males but not in females. In the present study, male and female prairie voles were exposed to either a 3-min swim stressor or no stressor; 45 min later each animal was tested in a parental care paradigm.

Developmental effects of oxytocin on neural activation and neuropeptide release in response to social stimuli.

Previous studies have revealed that the neuropeptide hormone oxytocin (OT) has developmental effects on subsequent social behavior and on mechanisms underlying social behavior such as OT neurons and estrogen receptor alpha. This suggests that OT might also have developmental effects on neural responses to social stimuli. This was tested in socially monogamous prairie voles (Microtus ochrogaster) by manipulating OT on the first day of life and then assessing the response to a heterosexual pairing in adulthood.

Mechanisms underlying epigenetic effects of early social experience: the role of neuropeptides and steroids.

In mammals the neonatal period is a time of significant social interaction. This is true even in solitary species as females spend a significant amount of time nursing and caring for their offspring. In social species interactions may also include the father, older siblings and extended family members.

Estrogen receptor alpha and vasopressin in the paraventricular nucleus of the hypothalamus in Peromyscus.

The purpose of this study was to determine the presence of estrogen receptor alpha (ERalpha) and the relationship between neurons that express ERalpha and produce vasopressin (AVP) in the paraventricular nucleus of the hypothalamus (PVN) in new world mice of the genus Peromyscus. Brains were collected from male and female Peromyscus californicus, Peromyscus leucopus, Peromyscus maniculatus, and Peromyscus polionotus, and double labeled for the expression of ERalpha and AVP immunoreactivity (IR). The number of cells expressing ERalpha-IR and AVP-IR was determined in the medial and posterior region of the PVN.

Early exposure to oxytocin affects the age of vaginal opening and first estrus in female rats.

Neonatal exposure to exogenous oxytocin (OT) can have long-term effects on the subsequent expression of adult behavior and physiology. Here, we test the prediction that early postnatal exposure to OT can affect the timing of sexual maturation in females, as indicated by the age of vaginal opening and the onset of first estrus. To test this hypothesis, female Sprague-Dawley rats received one of four treatments beginning on the day of birth and continuing for the next 6 days.

Developmental effects of oxytocin on stress response: single versus repeated exposure.

Both exogenous and endogenous oxytocin (OT) are associated with an attenuated stress response. Increased levels of OT in the early postnatal period have been shown to affect behavior and physiology in rodents, and these effects last into adulthood, suggesting an organizational role for OT during development. We investigated the effects of neonatal exposure to OT on the development of the stress response in male and female prairie voles (Microtus ochrogaster).