Oxytocin modulates fear responses by enhancing the maintenance of social memories. Rats that are genetically modified to have a surplus of oxytocin receptors display a greater fear response to a previously conditioned stressor. Oxytocin enhances the aversive social memory, leading the rat to display a greater fear response when the aversive stimulus is encountered again. Mood and depression
Oxytocin produces antidepressant-like effects in animal models of depression, and a deficit of it may be involved in the pathophysiology of depression in humans. The antidepressant-like effects of oxytocin are not blocked by a selective antagonist of the oxytocin receptor, suggesting that these effects are not mediated by the oxytocin receptor. In accordance, unlike oxytocin, the selective non-peptide oxytocin receptor agonist WAY-267,464 does not produce antidepressant-like effects, at least in the tail suspension test. In contrast to WAY-267,464, carbetocin, a close analogue of oxytocin and peptide oxytocin receptor agonist, notably does produce antidepressant-like effects in animals. As such, the antidepressant-like effects of oxytocin may be mediated by modulation of a different target, perhaps the vasopressin V1A receptor where oxytocin is known to weakly bind as an agonist.Oxytocin mediates the antidepressant-like effects of sexual activity. A drug for sexual dysfunction, sildenafil enhances electrically evoked oxytocin release from the pituitary gland. In accordance, it may have promise as an antidepressant. Sex differences
It has been shown that oxytocin differentially affects males and females. Females who are administered oxytocin are overall faster in responding to socially relevant stimuli than males who received oxytocin.
Maffucci syndrome is a very rare disorder in which multiple benign tumors of cartilage develop within the bones (such tumors are known as enchondromas). The tumors most commonly appear in the bones of the hands, feet, and limbs, causing bone deformities and short limbs.It is named for the Italian pathologist Angelo Maffucci who described it in 1881. Fewer than 200 cases of this syndrome have been reported. Signs and symptoms
Patients are normal at birth and the syndrome manifests during childhood and puberty.The enchondromas affect the extremities and their distribution is asymmetrical. The most common sites of enchondromas are the metacarpal bones and phalanges of the hands. The feet are less commonly affected. Disfigurations of the extremities are a result. Pathological fractures can arise in affected metaphyses and diaphyses of the long bones and are common (26%). The risk for sarcomatous degeneration of enchondromas, hemangiomas, or lymphangiomas is 15–30% in the setting of Maffucci syndrome. Maffucci syndrome is associated with a higher risk of CNS, pancreatic, and ovarian malignancies. Multiple enchondromas may present in three disorders: Ollier disease, Maffucci syndrome, and metachondromatosis. It is important to make the distinction between these diseases, particularly Ollier disease and Maffucci syndrome. Ollier disease is more common than Maffucci syndrome, and presents with multiple enchondromas often in a unilateral distribution. However, hemangiomas and lymphangiomas are not seen in Ollier disease. Metachondromatosis demonstrates autosomal-dominant transmission and presents with both multiple osteochondromas and enchondromas.It is associated with multiple cavernous hemangioma and phlebolith. Lymphangiomas may also be apparent.