Induction of maternal behavior in non-parturient adoptive mares

How Relevant is the Systemic Oxytocin Concentration for Human Sexual Behavior? A Systematic Review

Introduction

Despite its role in social cognition and affiliative behavior, less is known about the role played by oxytocin in human sexual behavior.

Aim

In the present systematic review, we aimed to find the levels of oxytocin related to human sexual arousal and orgasm.

Methods

We conducted the study according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. We performed a systematic search in the principal databases for studies that reported collection of salivary or plasmatic samples, with dosage of oxytocin in relation to sexual activity during induction of sexual arousal and orgasm.

Results

414 articles were obtained. After duplicates removal and the application of pre exclusion criteria, 16 articles were considered eligible and 13 articles were included with a Cohen's k of 0.827. Most of the studies used sexual self-stimulation and collected plasmatic or salivary samples to measure oxytocin. The sexual arousal and orgasm were assessed based on subjective reports.

Main Outcome Measure

The primary outcomes were the oxytocin levels collected during the induction of sexual arousal and orgasm.

Conclusions

Several studies collected only subjective reports about the sexual arousal and the orgasm. Most of the studies found higher levels of oxytocin during the orgasm or ejaculation. Given the sexual arousal evoked by self-stimulation in which sexual fantasies play an important role, it should be possible to postulate for a role of the oxytocin in sexual desire. In particular, we hypothesize a complex role of the oxytocin in the modulation of sexual fantasies and thoughts that are relevant in the sexual desire and help to trigger genital and sexual arousal.

Cera N, Vargas-Cáceres S, Oliveira C, et al. How Relevant is the Systemic Oxytocin Concentration for Human Sexual Behavior? A Systematic Review. Sex Med 2021;9:100370.

Cesarean Section or Natural Childbirth? Cesarean Birth May Damage Your Health

The increasing popularity of Cesarean birth has become a social concern in many countries. This paper reviews the literature on the effects of Cesarean section on children's psychological health. The results show that Cesarean birth may have adverse effects on children's sensory perception, sensory integration ability, neuropsychiatric development, and the infant-mother relationship. However, there remain deficiencies in extant research methods, research content, subject groupings, and interpretation of research results. Future research should improve research methods, broaden the research content, and refine the grouping of children born by Cesarean section. The exploration of neural mechanisms is also needed, as well as research directed toward suggesting effective interventions to reduce unnecessary Cesarean sections.

High interindividual and intraindividual variation of oxytocin secretion in estrous mares exposed to stallions, but no significant link to mate preferences

Oxytocin is a hormone that may not only influence reproductive mechanisms in mammals but also their social behavior, including pair bonding. We therefore tested if the concentrations of oxytocin and other hormones reveal mate preferences of 13 mares in estrus. Each mare was first exposed to two stallions (haphazardly selected out of seven) and her behavior recorded. The mare was then returned to her box (i.e., no contact to stallions during that time). Approximately 4.5 hours later, venous blood samples were collected every minute during 30 minutes preceding exposure to one of the two previously used stallions, 6 minutes during exposure, and 30 minutes after exposure back in the mare's box. The procedure was repeated in the consecutive estrus cycle, with the difference that the mare was each exposed to the other of the two stallions during oxytocin measurements. In 20 of the 26 trials, oxytocin concentrations were significantly elevated during exposure to the stallion, without significant associations to cortisol and estradiol concentrations. We found no significant association between oxytocin secretion and preferences in the previous choice situation. While estradiol concentration showed a high repeatability over the two cycles, we found considerable intraindividual differences in oxytocin and cortisol plasma concentration among the two cycles. Partially, the variation in oxytocin concentrations could be linked to the time of ovulation, with lower oxytocin plasma concentrations in mares which ovulated later than expected. In conclusion, when teasing under experimental conditions, we found high interindividual and intraindividual variation among mares in the increase of oxytocin plasma concentrations, depending on the timing of ovulation. However, oxytocin levels seemed to be no predictor of mare preference.

A wild Indo-Pacific bottlenose dolphin adopts a socially and genetically distant neonate

Alloparental behaviour and adoption have been reported in many mammals and birds. Such behaviours are energetically costly, and their causes and functions remain unclear. We observed the adoption behaviour of a wild Indo-Pacific bottlenose dolphin (Tursiops aduncus) near Mikura Island, Japan. A calf was seen with its mother on six observation days. Following the mother's death, the calf was observed with a sub-adult female on all 18 observation days from May to September 2012. On three days, the calf was observed swimming with this female in the suckling position and milk was seen leaking from the female's mammary slit. A five-year dataset revealed no significant social or kin relationships between the biological mother and allomother, indicating that kinship and social relationships did not play an important role in the observed adoption.

Management of the pregnant mare and long-term consequences on the offspring

The study of early developmental conditioning of health and disease in adulthood is particularly relevant in the horse, which is bred mainly to perform in demanding sport challenges. On the basis of this concept, the management of the broodmare could be considered an effective means to produce animals with the desired features. Knowledge on the Developmental Origins of Health and Disease in the equine species remains relatively scarce, with some experimental studies and one single epidemiologic study. Data highlight the determinant role of the maternal environment for postnatal body conformation, immune response, energy homeostasis, osteoarticular status and thyroidal, adrenocortical, and cardiovascular functions of the foal. Most research, however, focuses on the first months/years after birth. Long-term effects on the adult horse phenotype have not been investigated so far.

Foal Rejection - Characteristics and Therapy of Inadequate Maternal Behaviour in Mares

The bond between the mare and her newborn foal is usually a strong one. However, some factors can lead to aberrations of maternal behaviour. Failure to protect and nurse the foal is defined as foal rejection. With a long period of gestation and increasingly high value of foals, foal rejection causes severe losses to breeders. Horse owners and breeders should have knowledge of risk factors, types, prevention rules and treatment of inadequate maternal behaviour. In the case of foal rejection it is important to use fostering techniques in raising such foals.

Oxytocin role in enhancing well-being: a literature review

OBJECTIVES

Oxytocin (OT) has long been implicated in maternal bonding, sexual behavior and social affiliation behaviors. This paper reviews the wide effects of oxytocin and its key role in well-being.

METHODS

Studies were identified through Medline, Pubmed, and PsychINFO search of the English-language literature from the past sixty years (1959 to 2009) using the key word "oxytocin" in human studies. Of the 287 articles identified, 102 were selected for review.

RESULTS

OT induces a general sense of well-being including calm, improved social interactions, increased trust, and reduced fear as well as endocrine and physiological changes. Some central effects of OT are temporary and its release is associated with induction of secondary biochemical actions which mediate long-term benefits including blood pressure reduction, calm and affiliative behavior. As OT release is augmented by touch and physiological support so the hormone is involved in both the cause and benefits of social interactions. Just as OT has widespread effects in factors encompassing well-being, its dysfunction is associated with morbidity and decreased quality of life as observed neuropsychiatric conditions such as autism, schizophrenia and social phobias.

CONCLUSIONS

Oxytocin (OT) is of potential use in enhancing interpersonal and individual well-being, and might have more applications in neuropsychiatric disorders especially those characterized by persistent fear, repetitive behavior, reduced trust and avoidance of social interactions.

Pharmacokinetics of carbetocin, a long-acting oxytocin analogue, following intravenous administration in horses

REASON FOR PERFORMING STUDY

Current therapy protocols to treat persistent post mating endometritis and retained fetal membranes in mares typically include the administration of ecbolic drugs. Evaluation of the pharmacokinetics and tolerability of carbetocin, a long-acting oxytocin analogue, after i.v. administration is required.

OBJECTIVES

To determine the pharmacokinetic parameters (principally half-life) of carbetocin in horses.

METHODS

Five mature mares and one gelding received 0.175 mg carbetocin i.v. All animals were monitored periodically throughout the study for elevation in rectal temperature, heart rate, respiratory rate and signs of pain or discomfort. Plasma samples were collected for determination of carbetocin concentrations by radioimmunoassay.

RESULTS

Administration of carbetocin was well tolerated by all horses and its half-life was 17.2 min.

CONCLUSIONS

The half-life of carbetocin is greater than that previously reported for oxytocin (6.8 min).

POTENTIAL RELEVANCE

Carbetocin is an attractive alternative to oxytocin therapy in broodmare management.

Maternal brain response to own baby-cry is affected by cesarean section delivery

A range of early circumstances surrounding the birth of a child affects peripartum hormones, parental behavior and infant wellbeing. One of these factors, which may lead to postpartum depression, is the mode of delivery: vaginal delivery (VD) or cesarean section delivery (CSD). To test the hypothesis that CSD mothers would be less responsive to own baby-cry stimuli than VD mothers in the immediate postpartum period, we conducted functional magnetic resonance imaging, 2-4 weeks after delivery, of the brains of six mothers who delivered vaginally and six who had an elective CSD. VD mothers' brains were significantly more responsive than CSD mothers' brains to their own baby-cry in the superior and middle temporal gyri, superior frontal gyrus, medial fusiform gyrus, superior parietal lobe, as well as regions of the caudate, thalamus, hypothalamus, amygdala and pons. Also, within preferentially active regions of VD brains, there were correlations across all 12 mothers with out-of-magnet variables. These include correlations between own baby-cry responses in the left and right lenticular nuclei and parental preoccupations (r = .64, p < .05 and .67, p < .05 respectively), as well as in the superior frontal cortex and Beck depression inventory (r = .78, p < .01). First this suggests that VD mothers are more sensitive to own baby-cry than CSD mothers in the early postpartum in sensory processing, empathy, arousal, motivation, reward and habit-regulation circuits. Second, independent of mode of delivery, parental worries and mood are related to specific brain activations in response to own baby-cry.

Mother and newborn baby: Mutual regulation of physiology and behavior— A selective review

This article reviews 30 years of work demonstrating that interactions between mother and newborn infant in the period just after birth influence the physiology and behavior of both. Close body contact of the infant with his/her mother helps regulate the newborn's temperature, energy conservation, acid-base balance, adjustment of respiration, crying, and nursing behaviors. Similarly, the baby may regulate--i.e., increase--the mother's attention to his/her needs, the initiation and maintenance of breastfeeding, and the efficiency of her energy economy through vagus activation and a surge of gastrointestinal tract hormone release resulting in better exploitation of ingested calories. The effects of some of these changes can be detected months later. Parallels to animal research and possible mechanisms are discussed.

Induced lactation with a dopamine antagonist in mares: different responses between ovariectomized and intact mares

The aim of this study was to compare the effects of treatment with repeated injections of sulpiride (a dopamine D2 antagonist) on prolactin secretion and induced lactation in ovariectomized and intact adult mares and to verify if this induction was possible at the beginning and at the end of the birth season. Two experiments were carried out in September [experiment (expt) 1], and in March (expt 2), in France (48 degrees N). In expt 1, three groups of five mares were tested: intact-control, intact-treated and ovariectomized-treated mares. In expt 2, mares previously subjected to artificial photoperiod were assigned in two groups: four intact-control and five intact-treated mares. The cyclicity of intact mares was previously synchronized with PGF2alpha injections, then all the mares were in the follicular phase at the beginning of treatment. Sulpiride was intramuscularly injected (0.5 mg/kg of BW), twice a day. Mares were milked at 7:30, 11:45, 16:00 and 20:15 hours. Blood samples were collected every day during the treatment for progesterone, total oestrogen and prolactin assays. In the two experiments, only treated intact mares produced milk, with a large inter-animal variability. Prolactin increase after sulpiride treatment was not so great in the ovariectomized-treated mares as in the intact-treated mares. The total correlations between prolactin, progesterone, oestrogen plasma concentrations and daily milk production were significant (0.57, 0.25, 0.17 respectively). This induction of lactation can be performed during the entire birth season in intact mares, but not in ovariectomized mares, indicating that steroids are necessary for this induction in mares treated by dopamine D2 antagonist.