Oxytocin

Despite the dominant role of the hormone oxytocin (OT) in social behavior, little is known about the role of OT in the perception of social relationships. Furthermore, it is unclear whether there are sex differences in the way that OT affects social perception. Here, we employed a double-blind, placebo-controlled crossover design to investigate the effect of OT on accurate social perception. Following treatment, 62 participants completed the Interpersonal Perception Task, a method of assessing the accuracy of social judgments that requires identification of the relationship between people interacting in real life video clips divided into three categories: kinship, intimacy and competition. The findings suggest that OT had a general effect on improving accurate perception of social interactions. Furthermore, we show that OT also involves sex-specific characteristics. An interaction between treatment, task category and sex indicated that OT had a selective effect on improving kinship ...

There is now a well-established link between childhood maltreatment and psychosis. It is, however, unclear what the mechanisms are by which this occurs. Here, we propose a pathway linking the experience of childhood maltreatment with biological changes in the brain and suggest a psychological intervention to ameliorate its effects.

A 41-year-old woman with breast cancer was referred to the pain management clinic for a course of acupuncture for intense pain following a subcutaneous mastectomy and a latissimus dorsi flap reconstruction. She was treated with a standard course of acupuncture for breast pain, using paravertebral segmental points, trigger points, plus contralateral LI4 on the non-lymphoedematous arm. She experienced an episode of galactorrhoea six days following the first treatment and during the second treatment. She had not previously lactated for four years. CT and MRI of the brain revealed no focal abnormality. Acupuncture has been used in to promote lactation in the Traditional Chinese literature using the ‘Tianzong’ acupoint SI11. This acupoint coincided with a trigger point over infraspinatus that was included in the neurophysiologically based acupuncture treatment. Quantitative analysis has shown an increase in the production of prolactin and oxytocin following acupuncture. These hormones ar...

Cranial visceral afferents travel via the solitary tract (ST) to contact neurons within the ST nucleus (NTS) and activate homeostatic reflexes. Hypothalamic projections from the paraventricular nucleus (PVN) release oxytocin (OT) to modulate visceral afferent communication with NTS neurons. However, the cellular mechanisms through which OT acts are poorly understood. Here, we electrophysiologically identified second-order NTS neurons in horizontal brainstem slices by their low-jitter, ST-evoked glutamatergic EPSCs. OT increased the frequency of miniature EPSCs in half of the NTS second-order neurons (13/24) but did not alter event kinetics or amplitudes. These actions were blocked by a selective OT receptor antagonist. OT increased the amplitude of ST-evoked EPSCs with no effect on event kinetics. Variance-mean analysis of ST-evoked EPSCs indicated OT selectively increased the release probability of glutamate from the ST afferent terminals. In OT-sensitive neurons, OT evoked an inwa...

We conducted this study to determine what receptor mediates the effect of oxytocin to increase osmotic water permeability (Pf) in the rat inner medullary collecting duct (IMCD). Reverse transcription-polymerase chain reaction (RT-PCR) experiments demonstrated that mRNA for both the oxytocin receptor and the V2 receptor is present in the rat terminal IMCD. In isolated perfused IMCD segments, we found that the V2 vasopressin receptor antagonist [d(CH2)5(1),D-Ile2,Ile4,Arg8]vasopressin, but not oxytocin receptor antagonists, blocked the hydrosmotic response to 200 pM oxytocin. The selective oxytocin receptor agonist [Thr4,Gly7]oxytocin did not increase water permeability. Oxytocin also increased urea permeability in IMCD segments. Studies in IMCD suspensions showed that oxytocin increases adenosine 3',5'-cyclic monophosphate production in a dose-dependent fashion with a half-maximal (EC50) response at 5.2 nM. The dose-response curves were virtually identical for IMCD suspension...

Oxytocin, the peptide well-known for its hormonal role in parturition and lactation, is present in several extrahypothalamic brain areas besides the neurohyophyseal system. The peptide is found in neurons which send their projections to brain areas containing specific oxytocin-binding sites. Oxytocin is also released from its synapses in a calcium-dependent fashion and may be the precursor of potent behaviorally active neuropeptides. These findings suggest that this ancient neuropeptide acts as a neurotransmitter in the central nervous system. We have attempted to review the most recent behavioral, morphological, electrophysiological and neurochemical studies providing evidence that oxytocin plays an important role in the expression of central functions, such as maternal behavior, sexual behavior (penile erection, lordosis and copulatory behavior), yawning, memory and learning, tolerance and dependence mechanisms, feeding, grooming, cardiovascular regulation and thermoregulation.

Autism spectrum conditions (autism) affect ~1% of the population and are characterized by deficits in social communication. Oxytocin has been widely reported to affect social-communicative function and its neural underpinnings. Here we report the first evidence that intranasal oxytocin administration improves a core problem that individuals with autism have in using eye contact appropriately in real-world social settings. A randomized double-blind, placebo-controlled, within-subjects design is used to examine how intranasal administration of 24 IU of oxytocin affects gaze behavior for 32 adult males with autism and 34 controls in a real-time interaction with a researcher. This interactive paradigm bypasses many of the limitations encountered with conventional static or computer-based stimuli. Eye movements are recorded using eye tracking, providing an objective measurement of looking patterns. The measure is shown to be sensitive to the reduced eye contact commonly reported in autis...

The uterotonic characteristics and effectiveness of a single treatment with either oxytocin or carbetocin were quantified in early postpartum dairy cows after normal, uncomplicated calvings. Both the short-term (within 4 h), and the long-term effects (between 12 and 36 h) of the two treatments were compared. Between 14 and 16 h after parturition, 27 multiparous Holstein-Friesian dairy cows, without fetal membrane retention, were selected and divided into three groups. The first group (n = 9) was administered 50 IU oxytocin intramuscularly, the second group (n = 10) received 0.35 mg carbetocin, while animals of the third group (n = 8), serving as a control, were administered 5 mL saline solution. A transcervically introduced open tip catheter system was used for the non-invasive acquisition of the intrauterine pressure (IUP) recording. After digitalization, the signals were analyzed, using a specially adapted graphical software program. A significant short-term effect was found both ...